Today – 1/18 Critter in the news / weather report Reading background

Today – 1/18 Critter in the news / weather report Reading background
End of the dinosaurs (?) First writing assignment Reading background will be a little rough. Today’s lecture will be a lot about the human side of the story - the people who have hunted dinosaurs, how the fossils have been interpreted, and how they have been presented to the public. We will introduce many of the concepts that will be reinforced and fleshed out during the semester. We will also be refreshing you about the dinosaurs that you are probably already familiar with, a warm-up for when tackle the whole lot of them! End sed rx with geo maps and how to find the treas!

Possible test question
Peter Ward and Roger Smith in Gorgon want: To learn how mammals survived the end-Permian extinction event Evidence of dinosaur ancestors To determine if the Permo-Triassic extinction was sudden or gradual All of the above

Administration: “Get to know you” form worth 2 pts XC
Ross’ OH in Gould-Simpson 205

Boned found in Spain in The formal description was just published last month. These bones are very big! This is the largest dino ever found in Europe. The humerus is 6 ft long. Fossils are so beautiful!

Teeth tell us about the diet of this animal
Teeth tell us about the diet of this animal. These teeth aren’t suited for eating meat. Nor are they well suited for chewing. They are good for stripping vegetation.

Not the most realistic drawing, but this is what was released to the press.

Turiasaurus End of the Jurassic, 145 Ma
100+ feet long! Almost 100,000 lbs! sauropod - member of clade Sauropoda Other super-giants like Brachiosaurus and Seismosaurus more closely related to each other than to Turiasaurus Scientists used to think that all of the super-giants were fairly close to each other on the family tree, but this shows that sauropods farther away on the tree could also get humongous.

Last time: Biostratigraphy – Principle of faunal succession
Mammal-like reptiles of the late Permian* Mass extinctions

Meandering river Braided streams
Owens R, Ca. Note old channels and meanders. Conditions which promote braided channel formation are: an abundant supply of sediment rapid and frequent variations in water discharge erodable banks You can see the old channels in the meandering river photo. Not only is its current course meandering around on the flat plan, but the whole river meanders across the plane through time. Will cut off to form oxbow lakes. Meandering river Braided streams /

Meandering v. braided stream:
Braided streams: networks of interconnected channels that form where there is a large sediment supply, large fluctuations in flow levels, erodable banks Meandering river: think of large single channel slowly winding its way across a gently sloping plain. E.g. Mississippi R. Banks stabilized by well-established vegetation

Point out protons, neutrons, and electrons
Point out protons, neutrons, and electrons. Describe how protons define carbon, electrons can change in ions, C-12. Carbon atom

Carbon Isotopes All carbon atoms have 6 protons
98.9 % of carbon atoms have 6 neutrons, called C-12 1.1 % have 7 neutrons, called C-13 Plants prefer C-12 Scientists measure ratio in rocks, try to explain observations Stable isotopes, not radioactive like C-14 Example of the kind of story scientists make up to explain ratios: C-13 relative abundance spikes in limestone, therefore that is a time great biological activity, because the photosynthetic organisms are pulling C-12 out of the atmo, increasing atmo C-13 abundance, which dissolves in ocean, becomes incorporated in ls. At the same time, C-13 would be going down in terrestrial sediments, because so much organic material would be incorporated into it.

Ubiquity of this excursion allows for carbon isotope stratigraphy!
As with other extinctions, a major and abrupt 13C isotopic excursion has been documented in numerous PTB sections distributed across the entire earth, including Greenland, West Spitzbergen, the Carnic Alps Austria, Slovenia, northwest Iran, Armenia, Turkey, Nepal, Pakistan, New Zealand, several locations in China, and elsewhere (Baud et al. 1989; Magaritz et al. 1983; Dolenec 1996, 1998; Krull et al. 2000; Twitchett et al. 2001). Similar carbon isotope excursions have also recently been documented from P-Tr marine boundary sections in Slovenia (Dolenec et al., 2001), Japan (Musashi et al., 2001), and New Zealand (Krull et al., 2000). The shape of the curve in the most complete sections shows a relatively gradual decline beginning in the late Permian, with a sharp negative decline right at the boundary. Evidence presented by Rampino et al. (2000) from the Austrian GK-1 core indicate that the sharp drop at the P-Tr developed within less than 3-40ky, which is substantially shorter than the U-Pb estimate of Bowring et al. (1998) of less than 165k yr. It is important to note that this excursion shows up in both carbonate carbon [d13C(carb)], such as brachiopod and conodont shells and corals, but also in organic carbon such as kerogen [d13C(org)], which can is extracted from carbonates or other sedimentary rocks by leaching away carbonate. As noted below, the negative excursion even shows up in the bone apatite of terrestrial vertebrates. Although marine sections contain the most complete records of this carbon isotopic shift, it has also been documented in terrestrial PTB sections, for instance in paleosols and/or organic carbon from PTB sediments of the Karoo Basin, South Africa (Smith and Ward, 2001), Antartica (Krull and Retallack, 2000), and Australia (Retallack, 1999). One interesting aspect of the Karoo d13C profile is that two were constructed, one using the tusks of the mammal-like reptiles Dicynodon and Lystrosaurus, and another using paleosol carbonate nodules. The two resulting curves covary, with a large negative excursion occurring in the overlap zone of these two taxa. [In the portion of the section containing both Dicynodon and Lystrosaurus occur, they both yield similar values.] As a side note, one of the Antarctic early Triassic paleosols described by Krull and Retallack is a deeply weathered, well-developed Ultisol which is estimated to have formed over ~40-60Ky. As Erwin notes, "the isotopic signatures are so similar from sections ranging from restricted basins to open marine that the only reasonable conclusion is that the major shifts are globally synchronous events" (p. 198). As noted above, this shift has now been documented in carbonate and organic carbon in terrestrial sediments as well. What caused this negative carbon isotope excursion? Part of the excursion may have been caused by the release of volcanic CO2, or by the oxidation of buried organic matter as a result of the Changxingian regression. However, these alone do not explain the major spike seen at the P-Tr, since this spike developed very quickly (~>40k yrs; Rampino et al. 2000). A shift of the magnitude and rapidity seen at the P-Tr would seem to require the addition of isotopically very light carbon to the ocean-atmosphere system. CO2 from volcanic gasses (about -5) would not produce such a large shift. The oxidation of buried sedimentary organic matter (-20 to -25) could produce the shift, but it doeesnt seem likely to explain the rapid spike seen at the P-Tr, since calcuations show that gigatons would have to be oxidized and returned to the ocean-atmosphere system within less than a few hundred thousand years to produce the observed isotopic shift (Erwin, 1994, ). Methane carbon in the form of gas hydrates, on the other hand, is isotopically very 'light,' meaning that has a very low carbon C13/12 ratio. Gas hydrate is a "solid, ice-like substance, composed of rigid cages of water molecules that enclose molecules of gas, mainly methane" (Kevenholden). Massive amounts of methane hydrates (1x10^19 - 2x10^19g) exist in continental slope sediments today, at depths greater than ~ m. It is assumed that a similar amount existed in the Permian. Methane has a delta 13C value of -60, and calculations show that the P-Tr carbon isotope changes could be produced by dissociation of between 10 and 25% of existing resevoirs. The other explanatory advantage is that, unlike the buried organic carbon resevoir, the methane resevoir can be rapidly discharged into the ocean-atmosphere system, by oceanic warming. Converted to the gaseous state, the methane rapidly diffuses into the ocean and the atmosphere, is oxidized by methanotropic bacteria to form light CO2 and water [CH4+2O2->2H20+CO2]. The light CO2 is mixed with the oceans and atmosphere and incorporated into carbonates and organic matter, thus producing the observed carbon isotopic shift. Methane and CO2 are both greenhouse gasses. Thus, once methane begins to dissociate, the ocean-atmosphere system warms even more, releasing even more methane, etc., and a positive feedback is initiated. Perhaps the warming was initiated by volcanism, and the coup de grace was delivered by methane dissociation.

Features of the P-T carbon isotopic excursion
Ubiquitous – global, all kinds of rocks including limestone, paleosol nodules, kerogen, and vertebrate teeth! Means that something big happened and that this can be used to find the boundary anywhere rocks deposited across the right time span are exposed So fast and so extreme that it cannot be explained by volcanism or other “normal” processes In the previous example, C-13 went opposite in ls and terrestrial deposits, so this spike is unusual.

Release of methane from methane hydrates possible mechanism for isotope excursion. See notes on 2nd previous slide. My department is deeply involved in the study of methane hydrates. USGS

Methane hydrate mechanism:
Enormous amounts of natural gas are stored in solid H2O (ice – but not quite the ice we are used to) cages at the bottom of the sea and under permafrost. This methane is enriched in C-12! Methane is a powerful greenhouse gas so release of some would initiate warming, perhaps starting a positive feedback

Proposed causes of dinosaur extinction
Out-competed by smarter, egg-eating mammals Disease Falling sea level Volcanically driven climate change Asteroid strike! (had been written off by 1980 because no crater had been found) Address all of these - mammals had failed to outcompete them for 160 Ma, disease affecting plankton and dinos? Sea level had been much lower for much of the Jurassic when dinos really took off than it was at the end of the Cretaceous, volcanism causes warming (long-term), and it had been extremely warm earlier in the Cretaceous, although this is the most reasonable of the first four. It also can cause short-term acid rain, but the major volcanism ended 300 Ka before the extinction

1980 - Walter and Luis Alvarez discover iridium rich clay layer
Walter and Luis Alvarez discover iridium rich clay layer

Location of the Chicxulub crater - site of the K-T impact!
Location of the Chicxulub crater - site of the K-T impact!

Chicxulub - “tail of the devil”
The Chicxulub crater lies buried, straddling the northwest coastline of the Yucatán peninsula. In this plot three concentric gradient features outline a circular gravity low ~180 km in diameter. The crater's negative anomaly is complicated by regional anomalies, including a low extending to the south and fan-shaped anomalies extending to the north. The crater was named Chicxulub because its center lies near the coastal town of Puerto Chicxulub Three-dimensional Bouguer gravity anomaly map over the Chicxulub crater (North is up.). Compare with the regional Bouguer map also showing the shaded horizontal gradient. The crater is represented by the near-circular low central to the figure (with contained concentric structure). Notice that regional gravity anomalies interfere with the circular pattern (fan shape to the north and double low to the south) and that a gravity low expressed as a trough occurs to the east side. The origin of most of the regional anomalies is not yet known, but correlations to regional magnetic anomalies suggests that many are related to variations in the basement rocks of the peninsula.Note that this image is not showing the shape of the crater; the negative gravity anomaly of the crater corresponds to the relatively low densities of the rocks within the crater (breccias and the melt sheet) and the Tertiary sediments filling the crater. The double humped central gravity high corresponds to the central uplift buried deep within the crater. The Chicxulub crater has no central topographic feature - the central peak characteristic of smaller complex craters. Chicxulub is a peak-ring crater with a poorly known topographic ring occurring at 40 to 45 km radius from the crater's center. A few minutes after the impact the crater probably looked like a slightly larger version of the 165 km-diameter peak-ring crater Strindberg on Mercury . Subsequent erosion probably substantially removed the rim of Chicxulub before it was buried. (Image courtesy Geological Survey of Canada) Jan Smit was one of these scientists. In the early 1980's Washington paleontologist Thor Hansen was attracted to the area along the Brazos River in central Texas. This river is not decorated by many outcrops, but passes through a sandy bed. Hansen dated this bed as K-T in age, but surprisingly, didn't cause much excitement in the world of paleontology. But, one scientist who became excited was Jan Smit, who had an odd hunch. This hunch told him that the Brazos River was the key to the mysteries of the where to locate the crater. Smit first traveled to this Brazos River bed in the early 1980's, and immediately recognized its significance.In a 1985 paper co-authored with Ted Romein Smit included this statement about the Brazos, "This may be the first evidence of impact (?tsunami) triggered sediment." After Smit published his paper University of Washington paleontologist Judy Bourgeois followed his lead and traveled to this river bed to study the impact deposits. To her it was clear-only a very large tsunami could cause these sand beds. In 1988 Canadian scientist Alan Hildebrand decided that the Brazos River tsunami was the key in finding the elusive K-T crater.Just why, you ask? According to Walter Alvarez's book on the extinction, "T. rex and the Crater of Doom," "He knew that the tsunami could only have come from the south of Texas, because that was the direction toward deep water 65 million years ago, just as it is now. He reckoned that the impact site could not have been too distant from Texas, because the Gulf of Mexico is an enclosed body of water, protected from any tsunami that came from far away. Alan (then) focused his attention on the Gulf of Mexico and the Caribbean . " By the time Hildebrand egan his search Walter Alvarez thought of a new way of proving the theory that the impact occurred in or near the Gulf. "For some reason, I had never been particularly impressed with what I had heard about the Brazos River, but one day in early 1990 I had a new idea for a way to look for evidence of a tsunaminot by looking for the sedimentary deposits of the tsunami, but by looking for a gap in the sedimentary record due to tsunami erosion. I reasoned that an impact in an ocean would send tsunamis crashing into all the surrounding shorelines, eroding the continental-margin sediment.After the event was over, deposition would resume, and the result would be an unconformity-a gap in the sedimentary record-with the upper part of the Cretaceous missing, but the very basal Tertiary present. Even if the impact site had been on oceanic crust that had been subducted, tsunami erosion of the surrounding continental margins might reveal where the crater had been," Alvarez explained. Once he thought up his brilliant idea Alvarez began to comb through the records of hundreds of oceanic sediment cores taken by the Ocean Drilling Project.According to the great geologist, "There was only one place in the world with that kind of a gap in the record-it was the Gulf of Mexico. Suddenly, I started taking Alan Hildebrand's ideas very seriously." Later Hildebrand got his hands on a group of magnetic maps of the Caribbean sea floor and noticed a large circular pattern of gravity anomalities near the Yucatan. This suggested a buried crater. Hildebrand rushed to meet two local geologists-Antonio Camargo and Glen Penfield- who were experts on this site.In a captivating moment for paleontology-and science in general-the crater, called by the name Chicxulub, was found to be K-T in age. In a 1991 paper Hildebrand published his findings. According to Alvarez, "It was a bombshell. The Crater of Doom was found at last!Thor Hansen's fossil age, Jan Smit's hunch, Jody Bourgeois's detailed study, and Alan Hildebrand's relentless search had come to fruition." Since the discovery of the crater Smit has partaken in two major research projects aimed at proving that the crater is "The Crater." The first project began in February of 1991, and started off with a disappointment.Alvarez and Smit, who by chance was visiting Alvarez's Berkeley at the time, had set out on an expedition to Mexico in hopes of proving that the Chicxulub crater was not only K-T in age, but that it caused tsunamis. The trip started off on a down note, with no major discoveries, but on the last night of the trek Smit and Alvarez laid their eyes on what Alvarez describes as the most beautiful outcrop he has ever seen. Named Arroyo el Mimbral, this outcrop contained alternating beds of rippled sand and fine clay, which was caused by the infamous tsunami, which as Smit proved, really existed.In 1997 Smit tagged along on a NASA expedition to Belize and Mexico that was, once again, aimed to prove that Chicxulub was the K-T crater. On the expedition Smit's team discovered two important new sites which further proved just what happened one fateful day 65 million years ago.According to expedition co-leader Kevin Pope of Geo Eco Arc Research of California, "The (Mexico) site contains two layers of material, or ejecta, thrown out by the impact that flowed across the surface like a thick fluid, known as fluidized ejecta lobes. This is the closest surface exposure of ejects to the Chicxulub crater that has yet been found and the best example known on Earth from a really big impact crater."Following the trip to Mexico was a trip to Belize, where Smit and local geologist Brian Holland guided the expedition to a new ejecta site about 290 miles from the rim of the Chicxulub crater. This site in Belize contains tiny spheres of "altered green glass called tektites. " These tektites are rocks that have been melted to glass by the severe heat of an impact. Smit noted that these tektites were similar to those found in Haiti and northern Mexico. According to Smit, this finding links the stratigraphy of the Belize sites to the more distant Caribbean and Mexican ejecta sites. o, like with his research concerning the Arroyo el Mimbral outcrop, Smit further proved that Chicxulub was the crater. Smit, who works at the Free University in Amsterdam, is noted by Alvarez as a K-T expert.

Animation of Chicxulub crater formation

Evidence for K-T impact
World-wide clay layer with iridium, shocked quartz, spherules, and carbon 65 Ma tsunami deposits ringing the Caribbean Chicxulub crater

It was a BIG explosion! Asteroid or comet was 10 km (6 mi) across
Moving at 75,000 km/hr (45,000 mi/hr) 5 billion times the energy of Hiroshima World-wide forest fires, tsunamis, acid-rain, year-long “nuclear winter” At least 75% of all species went extinct, including 90% of all plankton The world’s leading experts on impacts are right here at the UA.

Add picture of meteor strike

Meteor crater, N AZ, 50ka, ¾ mi across, object was only 150 ft across!
July 1, 1999 Rutgers Researchers Team With International Group To Investigate One Of The Most Famous Meteorites In The World NEW BRUNSWICK/PISCATAWAY, N.J. -- Researchers studying remains of the Canyon Diablo impactor have been able to describe the changing character of the meteoroid as it traversed Earth's atmosphere and hit its surface, ascertain how the remaining fragments were formed, and determine where within the body of the meteoroid the fragments originated. Meteoroid refers to a natural object that moves through interplanetary space, as opposed to the term meteorite, which refers to such an object after it has fallen to Earth. The team, which included Rutgers chemists Dr. Christoph Schnabel and Dr. Gregory Herzog together with colleagues in Arizona, California and Australia, used ultrasensitive measurements and computer modeling to gain insight into meteoroid dynamics. The Canyon Diablo impactor was the object responsible for excavating Meteor Crater, the famous Arizona landmark. It struck the desert near Winslow, Ariz., some 50,000 years ago, producing a crater about 4,000 feet wide and 570 feet deep. This was the first crater on Earth to be identified as having been created by a meteoroid. "The original meteoroid was thought to have been about 100 feet in diameter weighing approximately 60,000 tons, but little of it remains intact today," said Schnabel, a postdoctoral associate in the department of chemistry at Rutgers. "Two types of material survive from the Canyon Diablo impactor - iron meteorites, which did not melt during the impact, and spheroids, which did," said Herzog, professor of chemistry with the Faculty of Arts and Sciences-New Brunswick. "Our challenge has been to determine the processes involved in the impact and the formation of the resulting products, specifically the spheroids -- millimeter-size fragments found in the soils around the crater." In the July 2 issue of Science, the authors describe how they were able to deduce the original depth within the body of the meteoroid of the material that melted to form the spheroids. At the Australian National University, co-author Dr. L. Keith Fifield and his group employed accelerator mass spectrometry to analyze a rarely measured radioisotope of nickel (59Ni). Known as a cosmogenic nuclide, the 59Ni was produced by cosmic ray bombardment in the outer shell of the meteoroid while in space, and the relative concentration of this nuclide serves as a good indicator of depth of origin of the spheroid fragments. The resulting depth figures were then compared with predictions from computer-modeled simulations of the impact that were carried out at the University of Arizona by another co-author, Dr. Elisabetta Pierazzo. Conclusions based on this comparison yielded new information about the dynamics of meteoroid strikes on Earth or other solid objects in the solar system, information that may be applied in general to medium-size meteoroids when they impact. For example, the researchers were able to conclude that the trailing hemisphere of the meteoroid was the likely location for the molten material that gave rise to the spheroids. They further assert that material in the leading hemisphere of the meteoroid would more readily have mixed with and been lost in a large volume of rock at the impact site. Four batches of spheroids had been analyzed with average masses in each group ranging from 1 to 10 mg. On average, the spheroids contained six to seven times less 59Ni than the meteorites. The 59Ni measurements yield evidence that the liquid material that formed the spheroids came from depths of 1.3 to 1.6 meters beneath the surface of the meteoroid. The researchers also concluded that most of the spheroids did not form when atmospheric resistance to the incoming meteoroid melted surface material and blew molten droplets away, as had been previously held. Rather, computer numerical modeling of the meteoroid and its impact suggests explosive or shock melting of most of the object and dispersal of the spheroid fragments upon impact. They contend that little, if any, of the meteor vaporized. Moreover, the impact modeling suggests that the impact velocity of Canyon Diablo was higher than the velocity normally assumed for such an impact. Full copies of the Science article, "Shock Melting of the Canyon Diablo Impactor: Constraints From Nickel-59 Contents and Numerical Modeling," can be obtained by contacting the American Association for the Advancement of Science at (202) ; fax (202) ; or NOTE

Asteroid 1950-DA, March 16, 2880 Asteroid (29075) 1950 DA was discovered on 23 February It was observed for 17 days and then faded from view for half a century. Then, an object discovered on 31 December 2000 was recognized as being the long-lost 1950 DA. (As an aside, this was New Century's Eve and exactly 200 years to the night after the discovery of the first asteroid, Ceres.) Radar observations were made at Goldstone and Arecibo on 3-7 March 2001, during the asteroid's 7.8 million km approach to the Earth (a distance 21 times larger than that separating the Earth and Moon). Radar echoes revealed a slightly asymmetrical spheroid with a mean diameter of 1.1 km. Optical observations showed the asteroid rotated once every 2.1 hours, the second fastest spin rate ever observed for an asteroid its size. Detection of A Potential Hazard When high-precision radar meaurements were included in a new orbit solution, a potentially very close approach to the Earth on March 16, 2880 was discovered to exist. Analysis performed by Giorgini et al and reported in the April 5, 2002 edition of the journal Science ("Asteroid 1950 DA's Encounter With Earth in 2880: Physical Limits of Collision Probability Prediction") determined the impact probability as being at most 1 in 300 and probably even more remote, based on what is known about the asteroid so far. At its greatest, this could represent a risk 50% greater than that of the average background hazard due to all other asteroids from the present era through 2880, as defined by the Palermo Technical Scale (PTS value = +0.17) DA is the only known asteroid whose hazard could be above the background level. A University of Michigan-led research team has discovered that for the first time in history, scientists will be able to observe how the Earth's gravity will disrupt a massive asteroid's spin. Scientists predict a near-miss when Asteroid Apophis passes Earth in An asteroid flies this close to the planet only once every 1,300 years. The chance to study it will help scientists deal with the object should it threaten collision with Earth. Only about three Earth diameters will separate Apophis and Earth when the 400-meter asteroid hurtles by Earth's gravity, which will twist the object into a complex wobbling rotation. Such an occurrence has never been witnessed but could yield important clues to the interior of the sphere, according to a paper entitled, "Abrupt alteration of the spin state of asteroid Apophis (2004 MN4) during its 2029 Earth flyby," accepted for publication in the journal Icarus. The team of scientists is led by U-M's Daniel Scheeres, associate professor of aerospace engineering, and includes U-M's Peter Washabaugh, associate professor of aerospace engineering. Apophis is one of more than 600 known potentially hazardous asteroids and one of several that scientists hope to study more closely. In Apophis' case, additional measurements are necessary because the 2029 flyby could be followed by frequent close approaches thereafter, or even a collision. Scheeres said not only is it the closest asteroid flyby ever predicted in advance, but it could provide a birds-eye view of the asteroid's "belly." "In some sense it's like a space science mission 'for free' in that something scientifically interesting will happen, it will be observable from Earth, and it can be predicted far in advance," Scheeres said. If NASA places measuring equipment on the asteroid's surface, scientists could for the first time study an asteroid's interior, similar to how geologists study earthquakes to gain understanding of the Earth's core, Scheeres said. Because the torque caused by the Earth's gravitational pull will cause surface and interior disruption to Apophis, scientists have a unique opportunity to observe its otherwise inaccessible mechanical properties, Scheeres said. Throwing the asteroid off balance could also affect its orbit and how close it comes to Earth in future years. "Monitoring of this event telescopically and with devices placed on the asteroid's surface could reveal the nature of its interior, and provide us insight into how to deal with it should it ever threaten collision," Scheeres said. The asteroid will be visible in the night sky of Europe, Africa and Western Asia. The asteroid was discovered late last year and initially scientists gave it a 1-in-300 chance of hitting the Earth on April 13, Subsequent analysis of new and archived pre-discovery images showed that Apophis won't collide with Earth that day, but that later in 2035, 2036, and 2037 there remains a 1-in-6,250 chance that the asteroid could hit Earth, Scheeres said. Conversely, that's a percent chance that the asteroid will miss Earth.

Unlike the K-T impact that killed the dinos, the cause of the P-T extinction is still the subject of vigorous debate! Small but vocal group advocates extraterrestrial impact. No iridium layer found. Some very icy comet?

Tethys Sea Pangea X The blue planet, 260 Ma
Final assembly of Pangea proposed as mechanism – changing climate and currents. Too slow. Karoo basin just uncovered from ice, terrestrial ecosystem established The blue planet, 260 Ma

Siberian Traps http://dsc.discovery.com
This is apparently a gorgon in the Siberian basalt! One-two volcanic punch mechanism. Several of the classic P-Tr sections in South China are capped by 3-6cm thick altered volcanic ash layers containing bypyramidal quartz, melt spherules, glass shards and isotopic ratios typical of siliciclastic rather than basaltic volcanism. The volume of these ash layers is estimated to be about 1000km3, equal to the volume of water flowing through the Yangtze River in one year (Zhou and Kyte, 1988). Analysis of 40Ar/39Ar data from two tuffs in southern China yield dates of /- 0.2 million years ago for the Permian-Triassic boundary, which is comparable to the inception of main stage Siberian volcanism at /- 0.3 million years ago (Renne et al., 1995). This is consistent with biostratigraphic data -- the basal tuffs of the Siberian volcanics are interbedded with midle late Permian fossils (Kozur, 1998). The P-Tr boundary occurred at roughly the same time as the extrusion of the largest known Phanerozoic flood basalts, the Siberian Traps. Laser-heating 40Ar/39Ar plateau dating indicates that the bulk of these basalts was erupted over an extremely short time interval at mean eruption rates greater than 1.3 cubic kilometers per year (Renne et al. 1991). These volcanic flows presently cover an area of 337,000 square kilometers. They are estimated to have a volume of about (estimates vary) million cubic kilometers of solidified basaltic lava. Spread evenly over the earth's entire surface, this volume of lava would produce a layer 10 feet thick. Volcanism on this scale would release massive amounts of CO2 and SO2, as well as aerosols that would block a significant amount of sunlight. Initially, this would result in cooling. However, the SO2 would leave the atmosphere in the form of acidic rain, and within a few months most of the particulate matter would be gone from the atmosphere. This may have played some role in the extinctions on land. However, the CO2 would remain, and this would result in warming. Assuming a volume of 2 x 10^6 km3 of basalt, and release of 5 x 10^12g CO2 per km3 of basalt, then the Siberian Traps would have released 1 x 10^19g of CO2 (Wignall, 2001). Warming as a result of volcanic CO2 may have resulted in the dissociation of methane hydrates, and the development of anoxic conditions in the oceans. Warming promotes anoxic is two ways. First, the solubility of O2 in water decreases with increasing water temperature. Second, warming can promote anoxia if the equator-to-pole temperature gradient is weakened, since this would weaken oceanic circulation (Hallam and Wignall, 1997, p. 141). Finally, warming via volcanic CO2 may have caused the dissociation of gas hydrates, which would cause even more warming. Siberian Traps

Proposed causes of P-T extinction:
Final assembly of Pangea – changes ocean currents, climate Volcanism – Siberian traps flood basalt, Chinese explosive volcanism. Release CO2, causes warming, promotes ocean anoxia by weakening currents, lowering O2 solubility, and melting gas hydrates. Impact Combination

Insert pic of AC Petrified tree?
AC shot from above! With inset of teeth Before looking at the history of dinosaur fossil discoveries, let’s look at some of the reasons people collect fossils. I collect fossils because I think they are just the coolest things ever and fill me with a sense of awe at holding an ancient extinct animal in my hand. This is probably the driving passion for all fossil collectors, whether they buy fossils for their personal collection, dig them up and sell them, or study them as part of a professional scientific career. For those of us who go out into the hills to find to find our own fossils, the treasure hunt is huge rush. I often find myself over-stimulated. Tell ‘em about the teeth dreams!

What fossils tell us about dinosaurs
How they looked - size, shape, skin How they behaved - diet, locomotion, social life, as parents Physiology - thermal regulation, growth patterns History of life - speciation and extinction, relationships among groups Environmental reconstruction, rock ages geochemistry, paleogeography, interaction between physical and biological worlds Here are some of the scientific reasons to study fossils, and these are some of the questions we will be trying to answer about dinosaurs, pterosaurs, and marine reptiles. The first three bullets are all important in figuring out the relations (fourth bullet). Interaction between phys and bio worlds is part of environmental reconstruction and geochemistry. Interactions between bio and physical are responsible for sea, atmo, and soil chemistry. How they looked - how we define dinosaurs as dinosaurs (more details later in the course). Was their skin scaly like a snake, bumpy like a Gila monster, feathered, furry? Colors? How they behaved - what did they eat, who ate them (coprolites, vomit fossils!), were they fast (JP scene, footprints), were they loners or herders (flockers), did they care for their children or just lay an eggs and bail? Live birth? Physiology - warm- or cold-blooded?(bone structure, predator-prey ratios, overall morphology) Growth rates History of life - are birds dinosaurs? How are the different dinos related? How are the pteros, MR’s, and dinos related? Why were dinos, dinos? Why did they go extinct? How do the physical and biological worlds interact?

inspired by Protoceratops? ↓
← Griffin inspired by Protoceratops? ↓ web.ukonline.co.uk/conker/ A legend the Greeks borrowed from Central Asia in the seventh century B.C. According to some folklorists, pre-Christian oral tales from Greece and Rome describe the griffin, a half-bird, half-mammal that guarded large amounts of gold in the Altai Mountains along now what is the border between Mongolia and China. Griffins walked on all fours and had wings that originated in the shoulder region, a horn rising from the top of their head, and a large beak. Immediately south of the Altai Mountains, which is a highly productive gold mining region, lies the Gobi Desert, where a particular section of sedimentary rock known as the Nemget Formation is exposed. The formation is loaded with fossils. This is where Roy Chapman Andrews and his crew found the world’s first big nesting site of dinosaur eggs in Coincidently it is also where they found the first skeleton of a relatively small horned dinosaur called Protoceratops, followed by a many more Protoceratops skeletons. During the course of two summers Chapman and his crew excavated more than one hundred of these skeletons. Protoceratops is by far the most common dinosaur in the Nemget Formation. In an extremely arid, wind-ridden environment where fossils tend to be unusually well preserved, Protoceratops skeletons are also usually easy to find. The bones are white, whereas the desert rock they are lodged in is bright red. It has been this way for countless millennia, the bones of Protoceratops weathering out of the sandstone cliffs for anyone passing by to see, like the nomadic peoples who inhabited the area twenty-seven hundred years ago. Legend of the western US Sioux: bones remains of giant serpents that burrowed their way into the ground to die after being struck by lightning

Plot rejected the idea that fossil shells had ever been living creatures and suggested that they were actually the crystallizations of mineral salts, their zoomorphic appearance as coincidental as the regular shapes of stalactites or snowflakes. According to the neoplatonic school of thought, the whole cosmos is a web of hidden affinities, made visible in the resemblances between Man and his external world, between the heavens and the Earth, and between living and non-living entities. Neoplatonists could therefore attribute organic resemblances to the action of a pervasive moulding force or "plastic virtue" that governed the growth of living organisms, but also operated within the Earth. For Plot, this "plastic virtue" was crystallization, which he felt capable of remarkable feats. About the Meg femur: he wondered whether it (and others like it) might be the bones of elephants brought to Britain during the Roman invasions, but soon realised this could not be the case, and finally settled upon what is, to us, an even more bizarre suggestion: giant human! 1763: redescribed by Richard Brookes and named Scrotum humanum! 1677 – Robert Plot publishes first known description of a dinosaur bone. However, he mistakes it for the femur of a giant human!

1815 – William Buckland finds Megalosaurus jaw
Buckland teacher of Lyell, inventor of term “paleontology” – study of ancient life Found bone 1815, obtained some more over the next few years, finally published By then he had a First to realize that many of Britain’s surface deposits were the result of the action of glaciers. Strange appetites: legend has it that he once a treasured relic the heart of a French king 1815 – William Buckland finds Megalosaurus jaw

1830’s – Meet Meg, plus the happy water lizard
1831 1830’s – Meet Meg, plus the happy water lizard home.uchicago.edu/~shburch/dinopaper.html The view of these new creatures as lizards was brought to fullness in the prehistoric art at the time. When Megalosaurus, Iguanodon and Hylaeosaurus were first discovered and described, most prehistoric scenes, found as the frontspieces in books, primarily focused on marine reptiles and pterosaurs because their skeletons were more well known. Thus a scene including them, while fantastical, would still be accurate. Scientists and artists at the time did not generally include the new reptiles in their scenes because the true form of them was not known, and if they were included, it was in a lesser role. August Goldfuss, professor of zoology and mineralogy at Bonn, printed in his illustrated monograph Fossils of Germany an early representation of a Megalosaurus as part of a scene drawn for him by Nicholas Hohe (Plate 1). Called the "Jura Formation" and printed in 1831, the scene depicts the Megalosaurus on the shore near the back of the plate amongst the horsetails. The animals looks much like a large monitor lizard, its sharp teeth displayed prominently. It rests near the water like a crocodile, indicating the possibility of an amphibious nature, as Buckland had suggested. A few years later in 1833 nearly the same Megalosaurus graced the cover of Penny Magazine as part of a prehistoric scene very similar to Goldfuss's (Plate 2). John Phillps, professor of geology at King's College in London, designed to accompany a series of short articles. Again, the monitor-Megalosaurus appears near the edge of the water, looking rather vicious. These were the first representations of Megalosaurus to be published, but the image didn't change until much later. 1833

1836 – Gideon Mantell discovers the teeth of Iguanodon
After consulting numerous experts, Mantell finally recognized that the teeth bore an uncanny resemblance to the teeth of the living iguana, except that they were twenty times larger. In this paper, the second published description of a dinosaur, he concluded that he had found the teeth of a giant lizard, which he named Iguanodon, or "Iguana-tooth." He speculated that if the teeth bore the same relative proportions in the living and fossil animals, then the Iguanodon must have been upwards of sixty feet long. More fossils hard to come by, found only the “horn”

Iguanodon – notice the sprawling legs
Mantell envisioned Iguanodon as an enormous iguana, and so it would appear in early representations. A lizard that large would be terrifying whether it was carnivorous or herbivorous, and as such all the representations tend to emphasize this monstrous nature. Such fantastical beasts lent themselves well to inflating popular interest in science. Iguanodon – notice the sprawling legs 1842 – Richard Owen defines the “Dinosauria”, which translates as “terrible lizards”

Depiction by Owen circa 1850
1842 – Richard Owen defines the “Dinosauria”, which translates as “terrible lizards”. Gives them an upright more mammal-like stance, makes them smaller, notes that they all have a set fused pelvic backbones (sacral vertebrae) making their existence on land possible. Shows problem of scanty material for reconstructions. Upright stance an improvement. Things gathering steam – dino eggshells and bones found in France, prosauropod Plateosaurus found in Germany. It was at this time that "dinomania" experienced it's first outbreak. The new creatures were so popular that local newspapers covered paleontologists' public lectures, reporting in some depth on the new announcements or theories.43 The advances in printing and transportation meant that several newspapers could be read by people throughout the country, circulating ideas much more quickly than before. Magazines like Penny Magazine, Penny Cyclopaedia, and the Magazine of Natural History published articles on the dinosaurs and quickly distributed new ideas about prehistoric times.44 Popular geology books like Mantell's Wonders of Geology enjoyed many editions, constantly updated with new information. The desire for information about prehistoric times spread internationally, especially to continental Europe where more popular books like Figuier's the World Before the Deluge were released. Charles Dickens wrote the new dinosaurs into his novel Bleak House in 1852, writing in his opening lines: "Implacable November weather. As much mud in the streets as if the waters had but newly retired from the face of the earth, and it would not be wonderful to meet a Megalosaurus, forty feet long or so, waddling like an elephantine lizard up Holborn Hill." Depiction by Owen circa 1850

Benjamin Waterhouse Hawkins’ 1853 dinosaur reconstructions being prepared for display in the Crystal Palace, Hyde Park, London Still, these sources only exposed the literate and learned public to dinosaurs, and as such dinomania did not really hit the take over until the Crystal Palace Exhibition opened. The exhibition was hyped by the press, making it a terribly great publicity stunt for Owen and his dinosaurs. The London Illustrated News published several articles about the exhibition, including teasing pictures of the dinosaurs partly completed (Plate 16). Hawkins was flooded with requests to view the models before completion. On December 31, 1853 Owen and Hawkins invited 21 distinguished guests, including wealthy patrons and well known scientists, to dine in the belly of the partially completed Iguanodon. The event was covered by the newspapers and was generally a smashing success. The names of Cuvier, Buckland, Mantell and of course Owen were strung up on plaques around the Iguanodon, lending their authority to the new models.46 The dinosaurs were a sensation before they were even released to the public. When the exhibition did open to the public, forty thousand spectators visited the irresistible statues of prehistoric life.47 The Crystal Palace Park was easily accessible by an inexpensive suburban train to Sydenham, exposing the dinosaurs for the first time to a broad social range of London. The dinosaurs quickly became the subject of cartoons in newspapers and magazines as their popularity grew. Models and posters of the Crystal Palace Park sculptures were sold as souvenirs and found their way into classrooms.48 The restorations were taken to be representative of the highest point of knowledge on the subject, and Owen did nothing to encourage ideas of other forms. Owen's certainty of his new interpretation of dinosaurs is evident in his guide to the Crystal Palace Park Exhibition. He was so confident that he made it seem like the dinosaurs are well known as far as fossil evidence goes, in order for his theories to seem less speculative. In the introduction, Owen writes, "those extinct animals were first selected of which the entire, or nearly entire, skeleton had been exhumed."49 While many of the other prehistoric animals were complete, the dinosaurs were far from it, and only a few specimens had any articulated bones. He describes a long process to make the models accurate, including being "rigorously tested" by anatomical standards.50 Owen even mentions inaccuracies and limitations for other prehistoric species, but not the problems with the dinosaurs. He goes on in the guide to describe in some scientific detail a few of the more important bones of each dinosaur. In his discussion of the Iguanodon, he again gives the impression that much of the animal is known, and although Iguanodon was the best known dinosaur at the time it was far from being well known. He even includes an illustration (Plate 17), showing how the bones would be situated under the skin an muscles, and it is obvious from the picture how little of the dinosaur is actually known. Owen does concede that Hylaeosaurus is the least complete of all the dinosaurs, saying that "the major part of which... is necessarily at present conjectural."51 Owen's guide makes it seem like his theories of the characteristics of dinosaurs were unequivocally the correct ones. With the general public convinced of the appearance of dinosaurs, other restorations published afterward necessarily had to depict them in that manner. Had these new ideas and representations not been so well distributed, dinosaurs in other forms may have been seen in restorations at that time. Indeed, the appearance of dinosaurs would not shift until the late 19th century when dinomania exploded in America and dinosaur hunters there would find much more complete skeletons indicating different forms. The success of Owen's representations of the dinosaurs was due not to their accuracy, but to their popular exposure. Mantell had even suggested that Iguanodon could have been partially bipedal, but this theory was ignored and fell by the wayside until American paleontologists would find fossils that validated it and convince the public of it's accuracy.

Hyde Park restored, CP moved to Annerly Hill, burned down 1936, recently park restored with new museum Their importance lies in their being the first attempt in the world to interpret what full-scale prehistoric animals would have looked like, and in that they set ideas so firmly in the public’s mind that it affected the science of these creatures.

Megalosaurus (“big lizard”): 30 ft long, 12 ft high, over a ton

Iguanodon (“iguana tooth”): 33 ft long, 16ft tall, 5.5 tons

Nicholas Steno – “Father of stratigraphy”
Second half of the 1600’s Said fossils were remains of organisms Principle of Original Horizontality – rock layers laid down horizontally, any deviation from this due to later disturbance Law of Superposition – lower layers are older, upper layers are more recent Despite a relatively brief scientific career, Nicholas Steno's work on the formation of rock layers and the fossils they contain was crucial to the development of modern geology. The principles he stated continue to be used today by geologists and paleontologists. Steno was born as Niels Stensen, but he is better known by the Latinized forms of his name, Nicholas Stenonis or Nicholas Steno. A native of Copenhagen, Denmark, Steno left Denmark in 1660 to study medicine at the leading center for medical education of his time, the University of Leiden in the Netherlands. After brief stints in Paris and Montpelier, he moved to Florence, Italy in His studies in anatomy attracted the attention of the Grand Duke of Tuscany, Ferdinand II, who was also a patron of the sciences. Duke Ferdinand appointed Steno to a hospital post that left him ample time for his research. Steno was also elected to the Accademia del Cimento (Experimental Academy), a body of researchers inspired by Galileo's experimental and mathematical approach to science. Steno's anatomical studies focused at first on the muscular system and the nature of muscle contraction -- for example, he used geometry to show that a contracting muscle changes its shape but not its volume. However, in October 1666, two fishermen caught a huge shark near the town of Livorno, and Duke Ferdinand ordered its head to be sent to Steno. Steno dissected it and published his findings in The figure at right shows the figure published by Steno of the shark's head and teeth (click on it to view a larger version). While examining the teeth of the shark, Steno was struck by their resemblance to certain stony objects, called glossopetrae or "tongue stones," that were found in certain rocks. Ancient authorities, such as the Roman author Pliny the Elder, had suggested that these stones fell from the sky or from the moon. Others were of the opinion, also going back to ancient times, that fossils naturally grew in the rocks. Steno's contemporary Athanasius Kircher, for example, attributed fossils to a "lapidifying virtue diffused through the whole body of the geocosm." Steno, however, argued that glossopetrae looked like shark teeth because they were shark teeth, that had come from the mouths of once-living sharks, and come to be buried in mud or sand that was now dry land. There were differences in composition between glossopetrae and living sharks' teeth, but Steno used the "corpuscular theory of matter", a forerunner of atomic theory, to argue that fossils could be altered in chemical composition without changing their form. Steno's conclusion may seem so blatantly obvious as to be insignificant. Furthermore, Steno was not the first person to link "tongue stones" with sharks' teeth. Steno's contemporaries Robert Hooke and John Ray also argued that fossils were the remains of once-living organisms. The Italian naturalist Fabio Colonna had stated that "tongue stones" were shark teeth in a book published in 1616, and others had noticed the similarity even earlier. However, it is important to remember that shark teeth, and some other fossils such as relatively young clams and snails, are "easy fossils" -- they resemble living organisms very closely. A great many fossils do not look like familiar living organisms at all. They may be preserved in an unusual way; they may represent only a part or fragment of an organism; they may belong to extinct taxa; and/or their living counterparts may be unfamiliar or unknown. In Steno's time, in fact, the word "fossil" could mean virtually anything dug from the Earth. Naturalists did not always distinguish between "fossils" that resembled living organisms, and "fossils" such as crystals and ores that did form within the Earth. For all these reasons, the distinction between which objects found in rocks were and were not once-living organisms -- if, indeed, any of them were -- was not at all obvious in the seventeenth century. Steno's work on shark teeth led him to the more general question of how any solid object could come to be found inside another solid object, such as a rock or a layer of rock. The "solid bodies within solids" that attracted Steno's interest included, not only fossils as we would define them today, but minerals, crystals, incrustations, veins, and even entire rock layers or strata. Steno's ideas on how these could form were published in 1669, under the title De solido intra solidum naturaliter contento dissertationis prodromus, or Preliminary discourse to a dissertation on a solid body naturally contained within a solid. (The book's title is often simply abbreviated to Prodromus.) Assuming that all rocks and minerals had once been fluid, Steno reasoned that rock strata and similar deposits were formed when particles in a fluid such as water fell to the bottom. This process would leave horizontal layers. Thus Steno's principle of original horizontality states that rock layers form in the horizontal position, and any deviations from this position are due to the rocks being disturbed later. Steno stated another, more general principle in this way: If a solid body is enclosed on all sides by another solid body, of the two bodies that one first became hard which, in the mutual contact, expresses on its own surface the properties of the other surface. In other words: a solid object will cause any solids that form around it later to conform to its own shape. Steno was able to show by this reasoning that fossils and crystals must have solidified before the host rock that contains them was formed. If a "tongue stone" had grown within a rock, it would have been distorted by the surrounding rock, in much the same way that a tree root is distorted by growing into a crack in the earth. Instead, the "tongue stone" must have been buried in soft sediments which hardened later. Veins (mineral-filled cracks) and many crystals, on the other hand, must have formed after the surrounding rock was a solid, because they often did show irregularities of form caused by having to conform to the surrounding solid rock. These, Steno argued, must have grown from fluids percolating within the Earth, in the same manner that crystals could be made to grow in chemistry experiments. Finally, in the case of strata, layers on top of a set of strata conform to the shape of lower layers. . . and therefore, in a set of strata, the youngest layers must be those of the top, and the oldest must lie on the bottom. This conclusion also follows from Steno's reasoning that rock strata form when particles fall out of suspension in a fluid -- but it also applies to rocks that do not form in this way, such as many igneous rocks. This is now referred to as Steno's law of superposition: layers of rock are arranged in a time sequence, with the oldest on the bottom and the youngest on the top, unless later processes disturb this arrangement. It is Steno's most famous contribution to geology. Steno realized that other geological processes could create apparent exceptions to his laws of superposition and horizontality. He reasoned that the formation of caves might remove part of a lower layer, and that the collapse of a cave might transport large pieces of an upper layer downwards. He recognized that rocks might be uplifted by subterranean forces. Geologists now recognize that tilting, folding, and faulting may also complicate the analysis of a stratigraphic sequence. Molten rock may force its way through surrounding rocks and may sometimes squeeze between older rock layers, also forming an exception to Steno's law. However, such anomalies leave physical evidence in the disturbed rocks; for example, faulted rock layers may be cracked, broken, or metamorphosed along the fault line. It should also be remembered that Steno's law is a statement of relative time, not absolute time: two rock layers, in principle, could have formed millions of years apart or a few hours or days apart. Steno himself saw no difficulty in attributing the formation of most rocks to the flood mentioned in the Bible. However, he noticed that, of the two major rock types in the Apennine Mountains near Florence, the lower layers had no fossils, while the upper ones were rich in fossils. He suggested that the upper layers had formed in the Flood, after the creation of life, while the lower ones had formed before life had existed. This was the first use of geology to try to distinguish different time periods in the Earth's history -- an approach that would develop spectacularly in the work of later scientists. Steno essentially abandoned science after his conversion to Roman Catholicism in 1667, much to the dismay of some of his scientific colleagues. He was ordained as a priest in In 1677, he became a titular bishop, and spent the rest of his life ministering to the minority Roman Catholic populations in northern Germany, Denmark, and Norway. He never wrote the larger work for which his Prodromus was meant to serve only as an introduction. Yet his brief Prodromus was recognized as an important contribution in its own right; it was widely circulated and translated into English. The data and conclusions that Steno put forth in his "preliminary discourse" were enough to have earned him the title of "Father of Stratigraphy."

Early 1800’s geology comes alive!
1795 – Theory of the Earth by James Hutton: how rock layers form, hot inside, old, uniformitarianism, natural selection 1815 – Geologic map by William Smith: biostratigraphy – Principles of Geology by Charles Lyell: stratigraphy 1859: On the Origin of Species by Darwin Late 18th century geology as a science begins to mature. James Hutton in 1795 publishes Theory of the Earth after studying rock layers in Scotland, outlines the process of rock layer formation, idea that Earth was hot inside and that this was driving the formation of new rock (as opposed to “Neptunism”), that Earth was much older than a few thousand years (actually proposed infinitely old) and changed with uniformitarianism. Also proposed natural selection! William Smith from family of simple farmers invents biostratigraphy (“principle of faunal succession”), 1815 publishes wonderful geological map of England, has his work stolen by “distinguished gentlemen”, ends up in debtor’s prison, is eventually vindicated, given first Wollaston medal by the Geological Society of London in 1831! Charles Lyell’s Principles of Geology published really laid the groundwork for modern geology, especially stratigraphy. Charles Darwin unpaid naturalist on the HMS Beagle (in fact, Dad had to pay 30 pounds a year!). Visits Galapagos. Idea of evolution in the air, but he really nails it down Darwin finally publishes “On the Origin of Species” archaeopteryx found, Owen (British Museum) pays L700 for a collection of 1000 specimens including the “London specimen”, publishes on it 1863, presents it as a bird. Neptunism is a discredited and obsolete scientific theory of geology proposed by Abraham Werner in the late 18th century that proposed rocks formed from the crystallisation of minerals in the early Earth's oceans. Another theory about that time was Plutonism. It was named after Neptune, the ancient Roman name for the ancient Greek god of the sea, Poseidon. Neptunism lost mainstream scientific support in the early 19th century as the principle of uniformitarianism was shown to fit better with the geological facts as they became better known.

Archaeopteryx – London specimen, found 1861
1861 archaeopteryx found, Owen (British Museum) pays L700 for a collection of 1000 specimens including the “London specimen”, publishes on it 1863, presents it as a bird. One of the criticisms of evolution was lack of transitional forms, but here’s one. Found in Solnhofen limestone of Germany. Toward the end of the Jurassic, about 155 milion years ago, a warm shallow sea studded with islands covered much of what is now Germany. Sponges and corals grew on rises in this sea, forming reefs that divided up parts of this sea into isolated lagoons. These lagoons were cut off from the ocean and also from terrestrial runoff. Within these warm, isolated lagoons, the salinity rose, and the water may have been anoxic (depleted of oxygen) or even toxic at various intervals. Aside from cyanobacteria and small protists such as foraminifera, nothing could survive in the bottom waters of the lagoons for very long, including bacteria that decompose dead things or bioturbators. However, any organism that fell into the lagoons from the land, or that drifted or was washed into the lagoons from the ocean, was buried in soft carbonate muds. Thus, many delicate creatures were not consumed by scavengers or torn apart by currents. Anything that got into the lagoons soon died. Horesshoe crabs found fossilized at the end of their fossil trackways! Other things brought in by big storms. Lithography was the first fundamentally new printing technology since the invention of relief printing in the fifteenth century. It is a mechanical planographic process in which the printing and non-printing areas of the plate are all at the same level, as opposed to intaglio and relief processes in which the design is cut into the printing block. Lithography is based on the chemical repellence of oil and water. Designs are drawn or painted with greasy ink or crayons on specially prepared limestone. The stone is moistened with water, which the stone accepts in areas not covered by the crayon. An oily ink, applied with a roller, adheres only to the drawing and is repelled by the wet parts of the stone. The print is then made by pressing paper against the inked drawing.

Taphonomy - the study of how fossils get preserved
How sedimentary rock deposits are formed and how dead animals get in them Help us understand ancient ecosystems Helps us understand biases in the fossil record Some organisms and parts of organisms rarely preserved Taphonomy is such an important concept that it has become a whole field of study and we will be talking about it throughout the semester. It involves reconstructing the physical and biological environment using geological, physical, and biological principles to come up with a story about how a particular fossil or assemblage of fossils got where they are. Then we can try to reach conclusions about how the animals lived. Cleveland-Lloyd dinosaur quarry example. Ecosystems - for instance, the study of the Solnhofen environment lets us know that many of the organisms weren’t living right there, must have been transported there by unusual events. Therefore, these organisms aren’t a representative example of a typical marine community 155 Ma. Rare preservation - soft bodied organisms, tissues, plants and animals living in mountains Biases - for instance, the record of marine invertebrates is far more complete than for any other group of organisms. Live in ocean, many have hard shells that fossilize easily, extremely common, live near shore - a sedimentary environment that is more commonly preserved in the rock record than any other Scientists really want to understand the patterns of biological diversity through geological time so we can place our own time in context and understand what is happening to us now. Taphonomy lets us evaluate the quality of our knowledge about past life, and gives us an idea of what will never be well known.

Solnhofen specimen - 60’s
Arguably the most famous fossil in the world. Berlin specimen Solnhofen specimen - 60’s

Nice reconstruction of what Archae may have looked like with clawed fingers, bony tail, and teeth. Tail feathers are coming off the bony tail, not forming the tail like in modern birds.

Pterodactylus kochi www.hayashibara.co.jp/html/shinka/
Preview of coming attractions: pterosaurs. This one from Solnhofen limestone, wingspan about 1 meter. Later we will look at the differences between birds, bats, and pteros in depth. paleo.cc/paluxy/livptero.htm Pterodactylus kochi leute.server.de/frankmuster/P/Pterodactylus.htm

Ichthyosaur from Holzmaden
Ichthyosaur from Holzmaden shale with live baby. Shale formed near Solnhofen deposits. Likely a birthing ground for ichthyosaurs, some fossils show live young in the process of being born. Dolphin-like, but… see if anyone picks up on tail fins being vertical, unlike dolphin fluke. Ichthyosaur from Holzmaden

Brief history of bird origins debate
Archae has teeth, hand claws, and a bony tail like dinos; but feathers like birds 1926 Heilmann decides birds did not descend from dinos because dinos lack wishbones (since found) 1964 Deinonychus discovered 1972 Walker suggests birds descended from an ancestral crocodilian 1870 Thomas Huxley announces birds descended from dinosaurs. 1926 Gerhard Heilmann puts birds as coming from an older animal, because some older animals had wishbones and dinosaurs didn’t (wrong – they had been discovered and misidentified. Even T. had them) Bones are not re-evolved. Wings of birds, bats, and pteros serve same function, but have very different structures. 1964 John Ostrom of Yale discovers Deinonychus in central Montana. Obviously agile, active, must have had bird-like metabolism 1972 British paleontologist Alick Walker says birds from crocodiles on the basis of jaw and middle ear convergences. However, birds and dinos share over 125 synapomorphies such as pneumaticized bones, and the number is increasing. Only a few nutjobs are holding out. Crocodiles, however, are birds closest relatives among living animals. Note to self: In this class we will examine many of the characteristics that place birds with dinosaurs including behavior (parental care, brooding), morphology (footprints, skeletal characteristics, four-chambered heart with single aorta, feathers), physiology (predator-prey ratio, endothermy, medullary bone) Today, it is almost universally accepted that birds are the direct descendents of dinosaurs, I.e. birds are dinosaurs

Deinonychus www.dinosoria.com
Robert Bakker’s classic illustration to John Ostrom’s 1969 paper on Deinonychus. Deinonychus a dromeosaur, close relative of velociraptor, but bigger (10 ft long, more like the JP “velociraptor”). Various proposals about how Deinon used this claw to rip open its prey.

Ichnology: study of trace fossils
Connecticut Valley dinosaur tracks described by Edward Hitchcock First recorded notice of these prints by farmboy Pliny Moody Later studied by Hitchcock, thought they were giant birds! Also described fossil dino poop, coprolites. William Clark of Lewis and Clark saw giant bones in Montana 1806, thought they were of a big fish. Probably dino or mososaur. Dino (prosauropod) bones found 1818, mistaken for human. Hitchcock invented the term ichnology (shortened form of ichnolithology - study of traces in rocks). This has become a very sophisticated science. There is at least one person who has made an entire career of studying dino poop.

1856 - Joseph Leidy publishes first description of North American dinosaur fossils
This is a very short, two-page paper, with no illustrations to arrest the eye, but if one takes the time to read the text, or even just the headings, a remarkable document comes alive. Ferdinand V. Hayden, in 1855, had conducted a geological survey along the Judith River in the Nebraska Territory, and he had found a number of large fossilized teeth belonging to some unknown animals. Hayden sent the specimens to Joseph Leidy, a physician and eminent naturalist of Philadelphia. Leidy recognized that some of these were the teeth of very large reptiles, and in this paper he identified and named eight genera, of which three turned out to be dinosaurs: Trachodon, Troodon, and Deinodon. This paper is the first published description of dinosaur remains in the United States. Leidy truly understood what he had found; although his Trachodon was classified primarily on the basis of one tooth, Leidy observed that it was an animal similar to Iguanodon, and he commented that the Deinodon teeth, although fragmentary, resembled those of Megalosaurus. Leidy “father of vertebrate paleontology” in NA. Trachodon = “rough tooth”, Deinodon = “terrible tooth”

The teeth identified by Joseph Leidy in 1856 were valid but scanty evidence of North American dinosaurs. Much more dramatic evidence was forthcoming in 1858, when several large limb bones, numerous vertebrae, some jaw fragments, and a few teeth were discovered at Haddonfield, New Jersey, and presented to the Academy of Natural Sciences in Philadelphia. Leidy recognized the fossils as belonging to a dinosaur like Iguanodon, and he named it Hadrosaurus foulkii, after the discoverer and benefactor. More remarkably, Leidy noted the disparity between the long hind legs and the short front legs and concluded: "The great disproportion of size between the fore and back parts of the skeleton of Hadrosaurus, leads me to suspect that this great extinct herbivorous lizard may have been in the habit of browsing, sustaining itself, kangaroo-like, in an erect position on its back extremities and tail." This is the first suggestion anywhere that some dinosaurs might have been, at least on occasion, bipedal. Teeth of chewer. Same guy who did London stuff makes recostruction (next slide). Hadrosaur “duckbill”

Dino tail drag marks virtually unknown, still not quite right, but getting closer.

The Hayden surveys of 1855 had turned up a tooth of what appeared to be a carnivorous dinosaur, and Leidy had assigned it the name of Aublysodon, but it wasn't until 1866 that more substantial evidence was discovered of carnivorous dinosaurs in the United States. In that year there was discovered in Barnesboro, New Jersey, the fossil remains of a new dinosaur. The fossils consisted of a jaw fragment, several limb bones, and some phalanges, or claws, and it was evident to Edward Cope of Philadelphia that this was a predator much like Megalosaurus. He named it Laelaps aquilunguis, and he was pleased at finding a carnivorous counterpart to the herbaceous hadrosaur of Leidy. As Cope later put it: "The discovery of this animal filled a hiatus in the Cretaceous Fauna, revealing the carnivorous enemy of the great Herbivorous Hadrosaurus, as the Aublysodon was related to the Trachodon of the Nebraska beds, and the Megalosaurus to the Iguanodon of the European Wealden and Oolite. In size this creature equalled the Megalosaurus bucklandii, and with it and Aublysodon, constituted the most formidable type of rapacious terrestrial vertebrata of which we have any knowledge."Cope described his find in a number of scientific journals, but he chose a popular journal for a pictorial reconstruction of the dinosaurs of New Jersey. Laelaps is the foreground dinosaur standing on a rock, confronting a marine Elasmosaurus, while Hadrosaurus feeds from a tree in the background.Although the Elasmosaurus, not being a dinosaur, is outside the scope of this book, we cannot resist pointing out something about Cope's restoration. It is well known in the history of paleontology that Cope initially reconstructed the skeleton with the head on the wrong end, that is, on the end of the tail. His error was pointed out by Othniel C. Marsh, thus precipitating a life-long feud, and a mortified Cope attempted to buy up the plates with the erroneous reconstruction and replace them with correct versions. The skeletal restorations, in both versions, have often been reproduced, but it has not been generally noticed that in this restoration, Elasmosaurus has its head on the short end, which is unfortunately the wrong end. Cope was unable to correct this one. Note stance of critters - a step backward. Myth that Marsh named coprolites after Cope, named by Buckland much earlier “Bone wars” raided each other’s quarries

 Stegosaurus ungulatus
Many of our best known and beloved dinosaurs came to light as a result of the bone wars. The “Great Dinosaur Rush” started in 1877 when two different people reported separately to Cope and Marsh about big dino bones outside of Morrison, Colorado. The sedimentary environment these bones were fossilized in was common throughout the West, and the rocks that formed from these sediments are called the Morrison Formation, and are found in several states. Stegosaurus, Allosaurus, Brontosaurus (now called Apatosaurus) came from Marsh’s Como Bluff, Wyoming quarry (Morrison Formation). Review top of p79 in Martin The golden year of 1877, which provided the first evidence of sauropods, also saw the discovery of the first stegosaur, in the very same upper Jurassic beds. Marsh announced the new genus in 1877, and in 1878 he discovered a nearly complete specimen, which he named Stegosaurus ungulatus. In ensuing years Marsh recovered more than twenty different specimens, which he grouped into a small number of species. However, he was seemingly reluctant to attempt a restoration, perhaps because he was uncertain as to how the plates and spikes should be placed. But in 1886 Marsh recovered the jewel of all stegosaur fossils, an articulated skeleton of Stegosaurus stenops, with the skull, vertebrae, limbs, and dermal armor in almost the position they were in when the animal died (for more on this specimen, see item 37). Marsh finally published the restoration as a line engraving in 1891; we see it here. He said the restoration was based on the type specimen of S.ungulatus, with the parts, especially the armor, positioned in accordance with the S. stenops specimen.This is an impressive restoration; it would not be out of place in a modern textbook, and yet it was done over one hundred years ago. Moreover, it shows a very unusual animal, as Marsh himself admitted: "The series of vertical plates which extended above the neck, along the back, and over two-thirds of the tail, is a most remarkable feature, which could not have been anticipated, and would hardly have been credited had not the plates themselves been found in position." Stegosaurus stenops 

Not everyone immediately accepted the interpretation of Marsh
Not everyone immediately accepted the interpretation of Marsh. Here the plates are used as scales to make a giant armadillo! I can really see why dinos so gripped the imagination of the public - these giant, ancient, monsters with such weird features! Must know more!

Allosaurus fragilis Allosaurus “different lizard” described by Marsh 1877 Allosaurus was a powerful predator that walked on two powerful legs, had a strong, S-shaped neck, and had vertebrae that were different from those of other dinosaurs (hence its name, the "different lizard"). It had a massive tail, a bulky body, and heavy bones. Its arms were short and had three-fingered hands with sharp claws that were up to 6 inches (15 cm) long.Allosaurus was up to 38 feet long (12 m) and 16.5 feet tall (5 m). It weighed about 1400 kg. It had a 3 feet long (90 cm) skull with two short brow-horns and bony knobs and ridges above its eyes and on the top of the head. It had large, powerful jaws with long, sharp, serrated teeth 2 to 4 inches (5 to 10 cm) long.Gastralia (hanging belly ribs) are thin, fragile ribs that helped support and protect the internal organs (like the lungs) in the middle area of the body. These ribs were not attached to the backbone; they were attached to the skin in the belly area.The different species of Allosaurus varied in weight. Allosaurus fragilis, A. atrox, and A. ferox weighed about 1.1 to 1.9 tons (1 tonne to 1.7 tonnes); A. amplexus was much heavier and weighed about 2.7 to 5.5 tons (3 tonnes to 5 tonnes).Point out cycad

1878 - Iguanodon mass grave found in Belgium
In 1878, deep underground in Bernissart, Belgium, miners tapped into what would prove to be a true mother lode of dinosaur fossils--dozens of Iguanodon skeletons jumbled together in a rocky matrix, many fully articulated. The fossils were slowly excavated, and Louis Dollo began to publish a series of papers based on the finds. Two different species were discovered, the smaller I. mantelli that was well known from the English Weald, and a new, larger species, I. bernissartensis. One conclusion was inescapable--after decades of debate over whether Iguanodon was bipedal or quadrupedal, the Bernissart specimens confirmed that Iguanodon was bipedal, and Dollo had it restored with a very upright posture.The first published restoration of I. bernissartensis appeared in this journal in 1882, but we chose for exhibition an 1884 restoration of I. mantelli, because of the unusual nature of the plate. First of all, it is a print made directly from a photograph, rather than a drawing. Second, it is a photograph of an actual mount, with the structural supports readily visible. If this is not the first published illustration of an actual skeletal mount, it is a close contender.Dollo's pose determined how iguanodons were be exhibited for nearly a century, especially when the British Museum in 1895 acquired a cast of a Bernissart Iguanodon and set it up in their Reptile Gallery. In April 1878 some Belgian coalminers discovered a mass of giant bones 322 metres underground at Bernissart, Belgium. 31 skeletons were extracted by scientists from the Royal Museum of Natural History in Brussels, under the direction of Louis Dollo. It seemed that all 31 adults had died in a deep ravine, though not necessarily at the same time. Dollo was able to prove that the Iguanodon was two-legged, and that the spike which Mantell and Owen had placed on it’s nose was in fact a thumb.Dollo spent nearly all his working life studying and reconstructing these skeletons, and his work took the study of dinosaurs to a new level. The skeletons were reconstructed in a church - the only building large enough - before being transferred to the museum, where they can still be seen today. Besides his extensive studies of Iguanodon, Dollo helped establish what is now known as paleobiology. He found that detailed studies of fossil anatomy could be used to reconstruct the adaptations of extinct animals. In 1893, he established Dollo's Law, also known as the Law of Irreversible Evolution. He hypothesized that organisms could evolve particular specializations but could not later lose those specializations. Horses, for example, could not re-evolve the side toes they had already lost. Advocated kangaroo like pose for life reconstruction, but did better fitting bones together. Some curators have even broken bones to make them fit their preconceptions. Up to 33 ft long, 5.5 tons

Brontosaurus, now called Apatosaurus
A nearly complete Brontosaurus skeleton was found in Lake Como, Wyoming, in 1879, by parties under the direction of Othniel C. Marsh. Marsh published a full skeletal restoration in Unfortunately, the skeleton lacked a head when found, so Marsh added a skull that was modelled on one found quite some distance away. We now know that the skull Marsh used belonged to a Camarasaurus, which is quite a bit shorter and wider than the proper skull (see detail at left). Marsh neglected to mention in the text that the restored skull was conjectural; later restorations continued to adopt the Camarasaurus-like skull for nearly a century (see item 41).In 1877, Marsh had found the bones of another large sauropod, which he had named Apatosaurus. Apatosaurus and Brontosaurus are now recognized to be synonyms, so the later name Brontosaurus is no longer scientifically valid, although it remains in public use. There is evidence for the herding behavior shown in this slide. Apatosaurus/Brontosaurus was one of the largest land animals that ever existed. The dinosaur Brontosaurus is now called Apatosaurus. This enormous plant-eater measured about feet (21-27 m) long and about 15 feet (4.6 m) tall at the hips. It weighed roughly tons (30-35 tonnes). Its head was less than 2 feet long; it had a long skull and a very tiny brain. This plant-eater had a long neck (with 15 vertebrae), a long whip-like tail (about 50 ft = 15 m long), a hollow backbone, peg-like teeth in the front of the jaws, and four massive, column-like legs. Its hind legs were larger than the front legs. Fossilized Apatosaurus footprints (called trackways) have been found (in Colorado, USA) that were about a yard wide. Brontosaurus, now called Apatosaurus

Ornithischia - “bird-hipped”
Saurischia - “lizard-hipped” Heads of animals off to left. Between 1866 and 1883, various authorities on dinosaurs, including Huxley, Cope, and Marsh, had produced classification schemes that attempted to bring order to the great variety of dinosaur specimens that had been and were being discovered. Marsh, in particular, had proposed to divide dinosaurs into four orders: sauropods, theropods, stegosaurs, and ornithopods; Cope had offered a different scheme. Most of the systems were based on foot structure, with teeth also taken into account.But in a paper delivered in 1887 and published in 1888, Harry G. Seeley pointed out that the term dinosaur was being used for two rather different kinds of reptiles. There were those, like Marsh's theropods and sauropods, that had a pelvis with a forward protruding pubic bone. And there were those, like the stegosaurs and ornithopods, that had a divided pubis, with one branch extending backwards along the ischium. Seeley saw this as a critical difference, and the basis for a fundamental dichotomy. Since the backward-protruding pubis is characteristic of modern birds, he called this group Ornithischia, the bird-hipped dinosaurs, and gave it the status of an order. The sauropods and theropods were placed in another order, Saurischia, or lizard-hipped dinosaurs. In the line drawing which he printed with the paper, the top two figures represent the Ornithischia, and the bottom two the Saurischia. Note that it would have been impossible for Seeley to have conceived his scheme much earlier than he did, for the sauropod and stegosaur orders (reduced by Seeley to sub-orders) had only just been discovered (see items 18 and 19). Ornithopods include hadrosaurs and iguanodonts. These obviously resemble each other and it would be reasonable to suppose that they are closely related. But stegosaurs look very different. However, when one looks at details, in particular the structure of the pelvis, one sees that they have strong similarities. Analogously, big meat-eaters like Allosaurus and giant long-necked herbivores like Apatosaurus look so different superficially, but their pelvic structures are clearly related. Pelvic structure can be used to lump all dinosaurs into two main groups - Ornithiscia and Saurischia. Ironically, birds descended from Saurishcians.

1889 - 1892 Hatcher finds 32 ceratopsians
All of the familiar characters we met in the last few slides, Allosaurus, Stego, Apato, were from Morrison Formation rocks, deposited in the late Jurassic Period, about Ma. Another employee of Marsh’s, John Bell Hatcher, did an amazing job of bringing us another familiar character from more recent rocks - Triceratops. In just three years, he found 32 skulls and skeletons of ceratopsians, mostly Triceratops, in Wyoming. Triceratops was a rhinoceros-like dinosaur. It walked on four sturdy legs and had three horns on its face along with a large bony plate projecting from the back of its skull (a frill). One short horn above its parrot-like beak and two longer horns (over 3 feet or 1 m long) above its eyes probably provided protection from predators. The horns were possibly used in mating rivalry and rituals. It had a large skull, one of the largest skulls of any land animal ever discovered. Its head was nearly one-third as long as its body. Triceratops hatched from eggs. Triceratops was about 30 feet long (9 m), 10 feet tall (3 m), and weighed up to 6 tons. It had a short, pointed tail, a bulky body, column-like legs with hoof-like claws, and a bony neck frill rimmed with bony bumps. It had a parrot-like beak, many cheek teeth, and powerful jaws. Hatcher invents first quarry map while working for Carnegie (diplodocus quarry). Helps us reconstruct taphonomy of early finds Hatcher finds 32 ceratopsians

Torosaurus Pentaceratops www.peabody.yale.edu
Full-size bronze of Torosaurus at Yale Peabody museum Torosaurus latus ("broad bull lizard") was a ceratopsid dinosaur species. It had the biggest head of any land animal known, reaching 8.5 feet (2.6 meters) in length — at least until a 10 foot (3 meter) skull of a Pentaceratops was discovered.About half the body of the Torosaurus was head, excluding the tail. In total, it was about 25 feet (7.6 meters) long and weighed 8 to 9 tons (7 to 8 tonnes). After this slide do exercise with ladder and tape measure to show how big these animals were. Also, do calcs using average weight = 150 lbs. Triceratops: 26 ft long, 8 tons, 10 ft tall T rex: 42 ft long, 13 ft tall at the hips, 7 tons Apatosaurus: 70 ft long, 15 feet tall at the hips, 33 tons

Restoration trach looks like it’s doing some sort of fancy dance step
Charles H. Sternberg and his sons--George, Charles F., and Levi--comprised one of the most formidable dinosaur hunting teams that ever attacked the fossil fields of the American and Canadian West. In 1908, in Converse County, Wyoming, they unearthed one of the most renowned of dinosaur fossils, the Trachodon mummy. Dinosaur skin impressions had been found before, but this specimen had the skin almost completely preserved, along with portions of muscle, and nearly the entire skeleton. Sternberg sold the mummy to the American Museum of Natural History for a considerable sum, and it immediately went on display.

Western Diamondback Rattlesnake
Western Diamondback Rattlesnake

Komodo Dragon

Pangolin  Rhinoceros skin  www.petinfo4u.com
Skin doesn’t tell us much about relationships - pangolin looks more like the incorrect stego restoration than anything else, and the hadrosaur skin looks a lot like the rhino! Pangolin  Rhinoceros skin 

Ceratosaurus - first (1884) really good carnivore skeleton
Even fifty years after the discovery of Buckland's Megalosaurus jaw, carnivorous dinosaurs remained a poorly understood group. Cope's Laelaps was known only from assorted fragments, and although a new carnivore, Allosaurus, was discovered in 1877, it too was represented only by assorted bits of teeth and bone. Finally, in 1884, the first reasonably complete skeleton of a theropod was found; it was named Ceratosaurus by Marsh, and Marsh published a restoration of the skeleton in As Marsh commented at the time, not only was the skeleton complete, but all the elements, including the skull, were found in position. Marsh restored it as a biped, with a stance similar to that of Dollo's Iguanodon.

Charles Knight - the first great dinosaur illustrator
Edward D. Cope had originally conceived of the American carnivore Laelaps as a fairly sedentary, if bipedal, predator (see item 11), but in his later years he began to envision carnivorous dinosaurs as capable of leaping through the air. Shortly before his death in 1897, he engaged Charles Knight to construct models of some of his dinosaur discoveries, and one of these was a marvelous realization of Cope's thoughts on active dinosaurs. Since the name Laelaps had been ruled invalid, due to prior use, the cavorting carnivores were now called Dryptosaurus. Charles R. Knight was the first great illustrator of dinosaurs, and perhaps still the champion of the art. We have already seen his 1898 model of a pair of dryptosaurs, his 1901 sculpture of Triceratops, and his 1907 painting of the browsing Diplodocus. By 1914 his fame was such that the American Museum Journal devoted an entire article to his craft. We are used to seeing color reproductions of his paintings today, but in the early decades of the century it was only the visitor to the American Museum or the United States National Museum who could see the original color canvases. Reproductions were scarce, and then always in black and white.One of Knight's finest drawings is shown above: Ornitholestes catching Archaeopteryx. Since it was executed in charcoal, nothing is lost but size in the black-and-white reproduction.

The most famous of all dinosaurs, Tyrannosaurus rex, was discovered by Barnum Brown in 1902 in Hell Creek, Montana, and it was first described here by Henry F. Osborn. The skeleton was not complete, but enough was present to attempt a reconstruction. So we have in this article the very first picture of T. rex. One of the nice features of the restoration is that it involved the collaboration of four of the truly great figures in the history of dinosaur discovery: Brown, who discovered the skeleton; Osborn, who named and described it; Richard S. Lull, who prepared the skeleton; and William D. Matthew, who drew the restoration. Lull and Matthew are featured later in this exhibition (see item 38 and item 42 respectively).A distinctive feature of the drawing is the inclusion of a human figure for scale. This is not the first time for such a comparison; Osborn had compared a human to a Diplodocus skeleton in 1899 (see item 25a). But the comparison is especially effective here; without it, the true size of T. rex could not be conveyed by this small text illustration. Matthew commented in a letter to his wife that the toothy smile of T. rex reminded him of President Roosevelt, and so he had taken to calling it "Teddysaurus.” Having found the first Tyrannosaurus specimen in 1902, Barnum Brown and the recovered a second one for the American Museum of Natural History in 1908, in the same location, Hell Creek, Montana. Between the two the Museum had a virtually complete skeleton, wanting only the belly ribs and fore-arms. Consequently the 1908 skeleton was prepared for mounting, supplemented as necessary with casts from the 1902 specimen, and the mount was completed in In this dramatic photograph, taken by Abram Anderson, we see the power of this wonderful mount. The jaw is wide, the head is cocked, the tail is sinuously curved, and the animals strides forcefully forward. Too many fingers. 1902, 08 - Tyrannosaurus rex found at Hell Creek, Montana by Barnum Brown

1910 - new kinds of hadrosaurs
Until 1910 or so, most hadrosaur specimens looked more or less alike, with similar flat, duck-bill-shaped heads, which was why paleontologists had trouble trying to decide whether they were dealing with one genus or several, and why there was such a confusion of names. Then, rather suddenly, a great variety of hadrosaurs, with unmistakably different head crests, began to be recovered from the Red Deer River in Alberta. Foremost in the hunt was Barnum Brown, who discovered Kritosaurus, Saurolophus, and Prosaurolophus in short order. But the prize specimen found by Brown was a skeleton of what he called Corythosaurus, after the helmet-shaped crest on the skull. The first specimen was found in 1912 and proved to be virtually complete and articulated, with even some skin impressions on one side. Although Brown published his find initially in 1914, we exhibit his second paper, because it includes a life restoration of Corythosaurus in its natural habitat (see illustration above). Brown thought Corythosaurus was a swimmer, for interesting reasons. He said that if you place the type specimen in a horizontal position, it looks like it is swimming (see second illustration at left). And indeed, the swimming figure in the restoration has exactly the same pose as the fossil. It is doubtful that Brown really thought that a Corythosaurus, having swum through life, would maintain this same posture as it died and awaited fossilization. Nevertheless, he looked at the fossil and saw a swimmer.

Roy Chapman Andrews - the real Indiana Jones
Went to find hominid fossils. Resulted in a series of expeditions that found many exciting critters, including Velociraptor. Ended with the rise of communism. Recently, E Asia has been the site of incredibly exciting dino finds. One of the most sensational events of the 1920s was the discovery of dinosaur remains in Mongolia. The Central Asiatic Expeditions were sponsored by the American Museum of Natural History and led by the flamboyant Roy Chapman Andrews. In 1923 they found abundant remains of a new kind of dinosaur, a primitive ceratopsian that was named Protoceratops andrewsi. The illustration at left shows a skull that was photographed as it was found, after some of the fine red sandstone had been chiseled away and cleaned up. The discovery of Protoceratops Another photograph in this issue (see right) shows Andrews holding a clutch of stone eggs. Perhaps the most newsworthy find of the expedition was the discovery of dinosaur nests containing fossilized eggs, for this was the first positive evidence that dinosaurs did indeed lay eggs. Since the eggs were found associated with more than seventy specimens of Protoceratops, it was naturally assumed that Protoceratops laid the eggs. Recent discoveries suggest that the nests actually belonged to Oviraptor, another dinosaur discovered on the Expedition, which for fifty years has been accused of stealing eggs, rather that laying them. Another dinosaur first described in this article was Velociraptor. The specimen consisted only of a skull with jaws, and some phalanges with a claw, but that was enough to indicate that Velociraptor was a small, light, and probably very swift predator. The skull, interestingly, was found lying right next to a Protoceratops skull, suggesting the identity of at least one of its prey.

Looked for sexual dimorphism, bone structure, very original thinker
Looked for sexual dimorphism, bone structure, very original thinker. By examining bone structure, he determined that a duckbill regarded as a new species was in fact a juvenile. Nopcsa was born to a long line of Hungarian aristocrats in 1877 in Transylvania, which at that time was a part of Austria-Hungary. In 1895 Nopcsa's younger sister Ilona discovered dinosaur bones from the family estate in Szentpéterfalva. This led to Nopcsa's enrolment to the University of Vienna to study the bones. He advanced quickly in his studies and gave his first lecture in the age of 22.In addition to dinosaurs Nopcsa had another passion: Albania. He was one the few outsiders who ventured into the hostile and mounaneous tribal areas in the North of the country. He learned local dialects and customs and eventually became to lead resistance against the Turks who occupied the region. He gave passionate speeches and smuggled in weapons. In 1912 the Balkan states joined forces to drive out the Turks. This was succesfull, but the newly-liberated states were immediately plunged into internal conflicts. Out of these conflicts Albania appeared as an independent state. In an international conference aiming to clarify the status of Albania Nopcsa was a contender for the throne of that country, but eventually lost.In the First world war Nopcsa was a spy for Austria-Hungary and also led a group of Albanian volunteers. At the end of the war Transylvania was ceded to Romania and Nopcsa lost his estates and other possessions. He was forced to pick up a job and became the head of the Hungarian Geological Institute.Nopcsa's tenure in the Geological Institute was short-lived. He moved to Vienna with his long-standing Albanian lover and secretary Bayazid Doda to study fossils. There he run into financial difficulties and was sidelined in his work. To cover his depts he had to sell his fossils to the Natural History Museum in London. Nopcsa became depressed and finally, in 1933, he shot first his lover and then himself. Franz Nopcsa

Scan cover of Dinosaur Dynasty and insert
Scan cover of Dinosaur Dynasty and insert. Available for 2 bucks plus shipping on Amazon.

Portions of the 1947 Zallinger mural at Peabody Museum, 110 ft wide by 16 ft high
If Charles Knight almost single-handedly determined how the public saw dinosaurs during the first half of the twentieth century, then Rudolf Zallinger did the same for the ensuing twenty-five years. In 1947 he completed an enormous fresco mural for the Peabody Museum at Yale University. It was a tour-de-force on all counts, and it came to the attention of the general public when Life Magazine included a reduced copy of the mural as a foldout in its series, "The World We Live In," which then appeared in book form. Oddly, the magazine reversed the painting; in the original mural, the dinosaurs appear in chronological order from right to left, but in the magazine, the older dinosaurs are at the left and the more recent dinosaurs at the right. Included animals from before dinos. Reflected popular and scientific thought until the 70’s. Things started to change with Deinonychus, Antartic dinos, bird-dino link, K-T impactor (dinos no longer seen as evolutionarily inferior), more.

Two kinds of fossils: Body fossils: preserved body parts such as bones, shells, eggs, skin impressions Trace fossils: preserved marks on the planet left by activity of ancient organisms such as footprints, nests, toothmarks, coprolites, fossil regurgitates. Trace fossils are especially important because they tell us about behavior! Body fossils are pieces of the animals. Some of the trackway stories are great! The nesting grounds that have been found in the last two decades are just amazing. Eggs with embryos in them! Oviraptor. Puking is bad for humans, but for many birds, it’s a way of life. Owl pellets, feeding young. Not much evidence for it in dinos.

How to fossilize a bone:
Death followed by burial Permineralization – pore spaces in the bone are filled with minerals precipitated from groundwater Replacement –original material is replaced by other minerals. Rare in bones, common in wood. Complete permineralization and replacement = petrification. 10,000 years minimum fossilization time Pass around fossils. More on burial next slide. Shells easiest to fossilize, then wood, bones. Soft parts very difficult, although probably if people excavating bones had been looking for it, more soft parts and skin impressions would have been found. Bones must be buried before they can be destroyed by scavengers or decomposed by bacteria. Some are transported long distances before burial (taphonomy). Skeletons are often disarticulated, scattered, only one or a few bones get buried. It can be a real mystery trying to figure our why there are only a couple of bones, wondering where the rest are. Some bones take much longer than 10,000 years to fossilize.

Sedimentary rocks Igneous rocks
How do you bury a bone? Usually in sediments, sometimes volcanic ash. The third kind of rock is metamorhic, that’s when you take one of these and squeeze it and bake it until there is no chance any bones are left. Even in this case, all info about life is not necessarily lost. Carbon isotope evidence of early life. Sedimentary rocks form when you take preexisting rocks, break them up and pile the fragments up in a low spot. They form horizontal layers (strata). Strata upturned by mountain building (as around here). Magma chamber and associated basalt flows. Igneous rocks

Sedimentary Rocks Record Environment
Sedimentary rocks – accumulations of fragments of pre-existing rocks lithify OR minerals precipitate from aqueous solution So how do they get buried. Usually found in sed rx, although sometimes in volcanic ash. Understanding how sedimentary rocks form is important for reconstructing the environment the dinos lived in, understanding how they did or didn’t get preserved (taphonomic analysis), and figuring out where the best place to look for dinos is. A = Sandstone (beach environment) B = Shale (shallow marine environment) C = Limestone (deeper marine environment)

Marine transgression – sea level rises
Take time with this diagram. Marine transgressions are very important, because seas can form on continents, much deposition happens. Things get preserved. Marine transgression – sea level rises

Stratigraphic column resulting from a marine transgression
limestone sandstone limey shale silty shale silty shale limey shale sandstone limestone Real life is not always so perfect, for instance around here in early Cretaceous sea transgressed, but shale is often missing from the rocks. Draw the simplified three-layer version on the digital dry-erase board. Beat it to death. Stratigraphic column resulting from a marine transgression Stratigraphic column resulting from a marine regression

Sediments come from eroding mountains Sediments sort by weight, so sand deposited at beaches, nearshore: makes sandstone Mud / clay deposited offshore: makes shale (too fine-grained to see individual grains) Calcite precipitated by marine organisms. Deposited in deeper waters where influx of terrestrial material is low: makes limestone Cement is produced from limestone, 50% world’s oil production comes from limestone traps

Sandstone and shale can also be formed from desert dunes, lake, river and floodplain, and delta deposits Most dinosaurs found in river, especially floodplain deposits A distinctive set of strata is called a formation

Western Interior Seaway – 80 Ma
During the latter part of the Cretaceous there was a fantastic transgression/regression event in N America. Subduction was happening along the W coast and the Rockies were forming as a result. Adjacent to the rockies the crust was pulled down, plus the climate was extremely warm, no ice caps, sea comes all the way from Gulf of Mexico to Artic. Use cellophane analogy. All along the western coastal plains of the WIS, big rivers ran out of the Rockies, fed into the sea, and deposited sediment that contains dinosaurs. This event provides us with a wonderful record of Cretaceous dino, marine reptile, and pterosaur life in N America. And everything else. Similar events are responsible for much of the fossil record. Shark eating tylosaur. Next day, big brother ate the shark! Western Interior Seaway – 80 Ma

Morrison Formation www.wvup.edu/ecrisp/fieldstudiesinutah.html
The Morrison Formation is extremely widespread, covering more than 1.5 million sq. Km of western USA. Within its spread it represents a number of environments, from hot, arid desert in the southwestern portions to a much wetter and swampier environment in the north. It has been radiometrically dated to Ma (Late Jurassic , Kimmeridgian ). It has yielded fish, frogs, salamanders, lizards, crocodiles, pterosaurs , small mammals, dinosaur eggs, and, of course, many dinosaurs, particularly sauropods . Within the Morrison Formation there are a number of famous and important localities. Canon City This site was first worked by Marsh and Cope in 1877, but many of the early specimens are now considered as nomina dubia . The most prolific site was the Marsh Quarry 1, which yielded 12 species including sauropods , theropods , ornithopods and stegosaurs , while sauropods were also found by Cope. The first named dinosaur from Canon City was Nanosaurus agilis, and the most important recent discovery is that of an almost complete specimen of Stegosaurus stenops with most of its armour preserved in place. This find has helped to establish that Stegosaurus actually had 2 alternating rows of plates along its back. Cleveland-Lloyd Quarry This quarry is part of the Brushy Basin member of the Morrison Formation from central Utah. It dates from the Tithonian and is one of the largest dinosaur accumulations. Work was begun in 1937 by Stokes and it is still being studied today. Representing a floodplain environment, possibly a ground-water fed wetland, the preserved fauna is almost all dinosaurs, and includes Allosaurus (material from at least 44 individuals that make up almost 75% of all remains), Ceratosaurus, Stokesosaurus, Marshosaurus, Camarasaurus, unidentified sauropods , Camptosaurus, Stegosaurus and a possible ankylosaur . The is ample evidence of both predation and scavenging . Como Bluff Como Bluff is one of the most renowned collecting areas in the USA. It is located in the Laramie Basin in south-eastern Wyoming and contains not only the late Jurassic Morrison Formation, but also the Cretaceous Cloverly Formation, a marine Jurassic formation (Sundance) and some Triassic beds. It has been worked since 1877, initially by Marsh and to a lesser extent Cope, and then the the American Museum of Natural History and many other teams. One of the best terrestrial faunas in the world, it contains vitrually everything from bivalves to pterosaurs , including lungfish, frogs and salamanders, turtles, lizards, rhynchocephalians , crocodiles and early mammals. Dinosaurs include a number of sauropods (Apatosaurus, Diplodocus, Camarasaurus, Pleurocoelus and Barosaurus) as well as Stegosaurus, Camptosaurus, Laosaurus, Othnielia, Drinker, Dryosaurus, Allosaurus, Ceratosaurus, Ornitholestes and Coelurus. Dry Mesa Quarry Dry Mesa Quarry is yet another of the Brushy Basin quarries of the Morrison Formation, and like most Morrison Formation sites, it contains no plant fossils. It does, however, have a diverse vertebrate fauna , including fish, amphibians , turtles, crocodiles, prototherian mammals, pterosaurs and, of course, dinosaurs, having the most diverse dinosaur fauna of any Morrison quarry. Camarasaurus, Diplodocus, Apatosaurus, Stegosaurus, Ceratosaurus, Marshosaurus, Stokesosaurus, Torvosaurus, Dystylosaurus, Supersaurus, Brachiosaurus and a nodosaurid have all been found there. It has a comparitively recent history, being opened in 1972 and worked ever since by teams from Brigham Young University. The Morrison Formation is a distinctive body of rock in the western United States and Canada that has been the most fertile source of dinosaur fossils in North America. It is composed of mudstone, sandstone, siltstone, and limestone; and is light grey, greenish gray, or red. Most of the fossils occur in the green siltstone beds and lower sandstones, relics of the rivers and floodplains of the Jurassic period. It is centered in Wyoming and Colorado, and includes parts of Montana, Saskatchewan, Alberta, North Dakota, South Dakota, Nebraska, Kansas, the panhandles of Oklahoma and Texas, New Mexico, Arizona, Utah, and Idaho. It covers an area of 1.5 million square km (600,000 square miles), though only a tiny fraction is exposed and accessible to geologists and paleontologists. Over 75% is still buried under the prairie to the east, and much of the rest was destroyed by erosion as the Rocky Mountains rose to the west. It was named for Morrison, Colorado, where the first fossils were discovered by Arthur Lakes in The same year, it became the center of the Bone Wars, a rivalry between early paleontologists Othniel Charles Marsh and Edward Drinker Cope. Geologic History According to radiometric dating, the Morrison Formation is between 145 and 154 million years old (Ma), which places it in the latest Oxfordian and Kimmeridgian stages of the late Jurassic. This is similar in age to the Solnhofen Limestone Formation in Germany, and the Tendaguru Formation in Tanzania. Through out the western US it variously overlays the Middle Jurassic Summerville, Sundance, Bell Ranch, Wanakah, and Stump Formations. At the time, the supercontinent of Laurasia had recently split into the continents of North America and Eurasia, though they were still connected by land bridges. North America moved north, and was passing through the subtropical regions. The Morrison Basin, which stretched from New Mexico in the south to Saskatchewan in the north, was formed when the precursors to the Front Range of the Rocky Mountains started pushing up to the west. The deposits from the basin, carried by streams and rivers from the Elko Highlands (along the borders of present-day Nevada and Utah), and deposited in swampy lowlands, lakes, and river channels, and floodplains, became the Morrison Formation. In the north, the Sundance Sea, an extension of the Arctic Ocean, stretched through Canada down to the United States. Coal is found in the Morrison Formation of Montana, which means that the northern part of the formation, along the shores of the sea, was wet and swampy, with more vegetation. Eolian sandstones are found in the southwestern part, which indicates it was much more arid — a desert, with sand dunes. In the Colorado Plateau region, the Morrison Formation is further broken into into four sub-divisions, or members. From the oldest to the most recent, they are: DINO 11541, an Allosaurus skull from the Salt Wash Member of the Morrison Formation. Windy Hill Member: The oldest member. At the time, the Morrison basin was characterized by shallow marine and tidal flat deposition along the southern shore of the Sundance Sea. Tidwell Member: The Sundance Sea receded to Wyoming during this member, and was replaced by lakes and mudflats. Salt Wash Member: The first purely terrestrial member. The basin was a semi-arid alluvial plain, with seasonal mudflats. Brushy Basin Member: Much finer-grained than the Salt Wash Member, the Brushy Basin Member is dominated by volcanic ash-rich mudstone. Rivers flowed from the west into a basin that contained a giant, saline alkaline lake called Lake T'oo'dichi' and extensive wetlands that were located just west of the modern Uncompaghre plateau. Deposition in the Morrison Formation ended about 145 Ma. It is followed by a 15 to 20 million year gap in the fossil record, marked by a calcrete layer, or limestone, which replaced the original sediment during soil formation. The next recognizable units are the Lower Cretaceous Cedar Mountain, Burro Canyon, Lytle, and Cloverly Formations. Fossil finds Though many of the fossils are fragmentary, they are sufficient to provide a good picture of the flora and fauna in the Morrison Basin during the Kimmeridgian. Overall, the climate was dry, similar to a savanna, but since there were no grasses, and no flowering plants or trees (angiosperms), the flora was quite different. Conifers were the dominant species of plant life at the time, with relatives of the modern ginkgo, cycads, tree ferns, and horsetail rushes. Much of the vegetation was riparian, living along the river valleys. Insects were very similar to modern species, with termites building 30 m (100 ft.) tall nests. Along the rivers, there were fish, frogs, salamanders, lizards, crocodiles, turtles, pterosaurs, crayfish, clams, and monotremes (prototherian mammals, the largest of which was about the size of rat). The dinosaurs were most likely riparian, as well. Hundreds of dinosaur fossils have been discovered, such as the Camptosaurus, Ornitholestes, and the Stegosaurus; mostly notably a very broad range of sauropods (the super-giants of the Mesozoic era). Since at least some of species are known to have nested in the area (Camptosaurus embryoes have been discovered), there are indications that it was a good environment for dinosaurs, and not just home to migratory, seasonal populations. Sauropods that have been discovered include the Diplodocus (most famously, the first nearly-complete specimen of D. carnegiei, which is now exhibited at the Carnegie Museum of Natural History, in Pittsburgh, Pennsylvania), Brachiosaurus, Apatosaurus (aka Brontosaurus), Camarasaurus, Titanosaurus, and the Seismosaurus. The very diversity of the sauropods has raised some questions about how they could all co-exist. While the body shape is very similar (long neck, long tail, huge elephant-like body), they must have had very different feeding strategies in order to all exist in the same time frame. Roughly three quarters of all Allosaurus fossils known have also been recovered from the Morrison Formation. The total is more than 60 partial and nearly-complete skeletons, including the first one ever unearthed (the holotype specimen). Sites and quarries Locations where significant Morrison Formation fossil discoveries have been made include: Workers inside the Dinosaur Quarry building, at the Dinosaur National Monument. Bone Cabin, Wyoming Canon City, Colorado: One of the three major sites excavated by the paleontologists Othniel Charles Marsh and Edward Drinker Cope during the Bone Wars in 1877, though most of the specimens were too incomplete to classify (nomina dubia). In 1992, a specimen of Stegosaurus stenops was discovered with its armor still in place, which confirmed that the dinosaur had two rows of plates on its back. Cleveland-Lloyd Quarry, Utah: First excavated by Lee Stokes in In the Jurassic, the quarry was a mudhole where several enormous sauropods got stuck, and apparently caused a feeding frenzy that lured and trapped many carnivorous dinosaurs. Most of the allosaurs are from this site, as well as the unique Stokeosaurus and Marshosaurus. Como Bluff, Wyoming: One of the most renown fossil sites in North America. It was first worked by Cope and particularly Marsh in 1877, and has been the source of many different sauropods and non-dinosaur species. The Cloverly Formation from the Cretaceous and some Triassic strata are also exposed at this location. Dinosaur National Monument, Utah Dry Mesa Quarry, Colorado: A wide variety of fauna, as well as the most diverse set of dinosaurs from any Morrison Formation quarry. The first dig was in 1972, by the Brigham Young University. Unique specimens include the longest dinosaur known, the Supersaurus, the chimeric Ultrasauros, and the largest carnivore on the continent, the Torvosaurus. External links and references Morrison Natural History Museum ( home page. Dinosaurs and the History of Life ( Columbia University lecture on the Morrison Formation. Geology of the (Dinosaur National Monument) Quarry ( from the National Park Service. The Morrison Formation ( from the Dinosaur Encyclopedia, including data on the major sites. Stump Formation (160 million years before present) Redwater Member: What was it like in this area before the dinosaurs lived here? Around 160 million years before present, a mountain range extended north-south along what is today the western border of Utah. While the southern half of the state was a terrestrial environment, an arm of the ancestral Pacific Ocean had advanced from the north, inundating Wyoming and parts of adjoining states including the Uintah Basin, and deposited sand, shale and lime mud that was later transformed into the Stump Formation. This ocean supported a diverse fauna that included belemnites, clams, snails, and ammonites. Toward the end of deposition of the Stump Formation, the area we now call Dinosaur National Monument was covered by the ocean. As these waters began to retreat, a new period of deposition was ushered in that would later become the Morrison Formation. It was during this time that dinosaurs roamed the region. The Morrison Formation has four members in the monument, each member representing a gradual progression of changes in the environment. Morrison Formation (155 to 147 million years before present) Windy Hill Member: Makes contact with the Stump Formation and is the oldest rock of the Morrison (155 million years before present). The Windy Hill is marine, deposited in an ocean with a regressive shoreline. Tidwell Member: Overlies the Windy Hill and represents broad coastal mud flats. As time passed the deposits became less marine as the influence of fresh water from rivers increased and river deposits increasingly became more dominant than marine deposits. The Tidwell has been dated at 155 million years before present. Salt Wash Member: Overlies the Tidwell and was a fully terrestrial environment. Braided rivers flowed down from moderately high mountains situated along today's Nevada/Utah border. This Morrison mountain range to the west, known as the Elko Highlands, was probably similar to the Sierra Nevada range in length, height, width, and effect. The mountains were high enough to cause a rain shadow over the Morrison landscape, which stretched out as a flat plain to the east. Some of the drainage was north toward present-day Wyoming, and some was east toward the present-day Mississippi River Valley. Salt Wash rivers shifted their courses often and reworked the deposits of sand, gravel, and mud transported by the rivers (The new species of Allosaurus jimmadsoni was found in river channel sands from this member of the Morrison.) The climate of this landscape east of the mountains was semi-arid. Prevailing winds, blowing from the west, picked up sand from river channels on the alluvial plain, and deposited it in dunes at and near the present-day Four Corners area. Occasionally the rivers flowed strong enough to reach the eastern plain creating seasonal mud flats. Breaking through this monotonous flat land were hills or low mountains, the ancestral beginnings of the Rocky Mountain range we know today. Brushy Basin Member: Overlies the Salt Wash and features two environmental characteristics that are different from the previous deposit. One of these was the rivers being confined to fairly straight, shallow valleys not present during the Salt Wash period. The mud embankments that formed the sides of the river valleys kept the rivers confined to straight or moderately sinuous courses running from the Elko Highlands to the west and the Mogollon Highlands to the southwest. Overbank flooding deposited mud rather than any considerable quantity of sand and gravel. The gradient of the rivers probably was less than during Salt Wash time. This entire region consisted of a gently sloping alluvial plain; the main topographic features being the gradual gradient to the east, the slight depressions of the river valleys, and the low ancestral Rocky Mountains to the east. The semi-arid climate persisted. Discharge waters from the rivers collected in the vast, landlocked Lake T'oo'dichi'. Here the evaporation rate was high, gradually concentrating salts, washed down by the rivers, into the lake. A second environmental difference to this landscape were volcanoes that arose in the mountain ranges to the west and began to eject ash into the atmosphere that eventually settled in this area. Each ash fall probably resulted in an accumulation of several inches, and, occasionally, several feet. Some of these falls may have had deadly effects on the plant and animals as well as the aquatic life in the rivers. The Dinosaur Quarry is in the Brushy Basin Member of the Morrison Formation. Because of the rain shadow caused by the mountains, the climate was semiarid, probably much like it is today, but without the cold winters. An example of how dry nonriparian communities could become is found at Deerlodge Park, where the Salt Wash Member of the Morrison outcrops. Here there is evidence of wind-blown sand dunes, suggesting a dry environment. The source of sand for the dunes was from river sandbars and beaches situated toward the southeast. The prevailing wind blew from the southwest to the northeast. The climate was also warm-warm enough that dinosaurs had no problems regulating their body temperature-but exactly how warm is not known. Typical river residents were aquatic insects, freshwater clams, crayfish, fish, turtles, crocodiles, and probably frogs and salamanders. In the shallow river valley, equiseturn, ferns, cycads, tree ferns, and conifers grew in abundance as riparian vegetation. On the land situated slightly above the river valley, plants of unknown species, probably used the same strategies to survive in the semi-arid environment as plants do today. They were probably widely dispersed with broad lateral root systems to gather up any rain that fell. Other xeric plants probably thrust roots deep into the soil to reach the water table, which was fairly close to the surface. Pollen and spore studies suggest there was a good diversity of plants considering the semiarid environment. This diversity was much lower on the arid lands than in the riparian community. Perennial and ephemeral ponds dotted the landscape. Perennial ponds were fed by the high water table. The origin of the high water table may have been water that percolated through the alluvial deposits that sloped down from the mountains. Ephemeral ponds were the result of overbank flooding from the river valleys into depressions. Since the climate was semiarid, the evaporation rate was fairly high and the humidity was probably low, resulting in a short life span for ephemeral ponds. Much like the creatures that inhabit today's slickrock potholes, ephemeral pond creatures had to hatch, mature, and lay eggs quickly. Ostracods and concostracons meet these requirements. In perennial ponds, frogs, salamanders, turtles, and crocodiles were typical residents. In its broader aspects, the Morrison landscape was varied. The area to the north in present-day Montana was close to the coast of the Late Jurassic ocean that extended into Canada. Here the Morrison has coal beds, representing a wetter environment with swamps and abundant vegetation. To the south of our region, beginning around present-day Grand Junction, Colorado and extending to near Albuquerque, New Mexico, there was a huge alkaline/ saline lake, a result of the arid climate during the latter part of Morrison deposition. What strikes me about the Morrison is that plants and animals faced a fairly harsh environment. The scarcity of water was the limiting environmental factor, like today. Natural events such as drought, drifting sand dunes, shifting riverbeds, floods, and volcanic ash falls could and did destroy parts of the ecosystem's communities, setting back plant succession and repopulation by wildlife. After an ash fall and subsequent to rains, the rivers probably flowed like thick soup, choked with silicious ash, suffocating and burying river residents. Herbivorous dinosaurs probably concentrated in the riparian community, although some species probably were adapted to the arid plains between the rivers. On the arid lands, bones of dinosaurs probably were not covered over and protected quickly enough to berome fossilized. So we do not know if one or more of the herbivorous species we have collected from the river channel sandstone in the Quarry would have foraged in these areas, or if some species, as yet undiscovered, lived on the dry plains. Was there enough plant material for the dinosaurs, or did they have to migrate to survive? From eggshell fragments and a Camptosaurus embryo we have found, we know that some of the dinosaurs nested here. That's an indication that the local environment met most of their habitat needs. Museum of the Rockies Paleontologist Jack Horner offered some of the following thoughts on this question. It is not logical to assume dinosaurs consumed food at the same rate as such contemporary large mammals as elephants. If you observe reptiles today, such as snakes, they eat several mice and won't eat again for a week or two. So the amount of plant material needed to sustain herbivorous dinosaurs was probably lower than we might assume at first. Also, why assume the dinosaurs were racing around burning up their energy, or that their digestive efficiency was as poor as mammal herbivores? Horner believes the dinosaurs lived here year-round, and didn't migrate, and that there was plenty of vegetation to sustain them. This may have been true for Montana, where coal swamps existed, but it doesn't seem to apply farther south on the Colorado Plateau, where coal is lacking and there are extensive deposits that indicate a dry or fairly dry environment. We also need to keep in mind that dinosaur populations probably rose and fell with the abundance of vegetation. It may be that the number of dinosaurs living in this area year round was small, given the harsh environmental conditions and the probable relatively low density of vegetation overall. The Morrison depositional period ended about 147 million years before present. The formation is overlain by the Lower Cretaceous Cedar Mountain Formation. The boundary between the Morrison and Cedar Mountain is marked by an unconformity and there is one or more layers of limestone called calcrete at or near this contact. The unconformity represents a 15 to 20-million-year gap in the rock record due to the erosion that took place during this period. Calcrete is a replacement limestone that forms below the surface of the ground from the action of highly calcareous ground water. To further illustrate that each rock formation represents an extinct ecosystem, and that the environments and their ecosystems continually change throughout time, I will describe. Talk about Tucson’s old high water table Morrison Formation

Laurasia Gondwana rainbow.ldeo.columbia.edu
Tendaguru in Africa fauna very similar to Morrison. Pangea has split into two supercontinents, which have begun to splinter, although this picture doesn’t show Gondwana coming apart, Australia and Antartica are just starting to break off of South America-Africa. Most workers on the Morrison believe the climate was at least seasonally dry. If we were to pick a modern environment with a similar climate, it might be in Kenya in the Serengeti Plain. This area is said be a Savanna, and it has often been said that the Morrison Formation had a Savanna-type climate. However, a Savanna is defined as being a vegetation type consisting of scattered trees with a ground cover of grasses or shrubs, with the trees covering less than 40% of the ground. It is usually assumed that the primary control of vegetation type is climate - so if you know the vegetation type you know the climate. However, during the Jurassic, there were no grasses, and there were no trees belonging to the flowering plants (angiosperms). So what does it mean to say that the area was a Savanna in the Jurassic? - not much! In fact, the most we can say is that the types of fossil soils present in the Morrison resemble those of a Savanna-type vegetation, and that it was at least seasonally dry. What we know of Morrison vegetation itself, which is not much, is that it was dominated by conifer trees of the Cheirolepidiaceous kind (as earlier in the Jurassic) along with trees related to the modern Gingko, ferns, and horsetail rushes. An important point to remember is that flowering plants were not at all common, if they were present at all. Insect communities were getting quite modern in appearance. Termites are especially important insects because they eat (and hence respire) huge amounts of plant matter. Although fossil termite nests have been found in Triassic strata (Chinle), by the Late Jurassic some termites were building gigantic nests some 30 m in height. The Ginkgo (Ginkgo biloba), sometimes also known as the Maidenhair Tree, is a unique tree with no close living relatives. It is classified in its own division, the Ginkgophyta, comprising the single class Ginkgoopsida, order Ginkgoales, family Ginkgoaceae, genus Ginkgo and just the one species. It is one of the best examples of a living fossil known. In the past it has also been placed in the divisions Spermatophyta or Pinophyta. Ginkgo is a gymnosperm (as opposed to an angiosperm), meaning "naked seed"; its seeds are not protected by a fruit. For centuries it was thought to be extinct in the wild, but is now known to grow wild in at least two small areas in Zhejiang province in eastern China, in the Tian Mu Shan Reserve. However, as this area has known human activity for over a thousand years, the wild status of ginkgos there is as of yet uncertain. Ginkgos are medium-large deciduous trees, reaching m tall (some specimens in China being over 50 m), with an The Ginkgo is a living fossil, with fossils recognisably related to modern Ginkgo from the Permian, dating back 270 million years. They diversified and spread throughout Laurasia during the middle Jurassic and Cretaceous, but became much rarer thereafter. By the Paleocene, Ginkgo adiantoides was the only Ginkgo species left in the Northern Hemisphere (but see below) with a markedly different (but not well-documented) form persisting in the Southern Hemisphere, and at the end of the Pliocene ginkgo fossils disappeared from fossil record everywhere apart from a small area of central China where the modern species survived. It is in fact doubtful whether the Northern Hemisphere fossil species of Ginkgo can be reliably distinguished; given the slow pace of evolution in the genus, there may have been only 2 in total: what is today called G. biloba (including G. adiantoides) and G. gardneri from the Paleocene of Scotland. Much more on Wikipedia.

Morrison Formation Late Jurassic, 154-145 Ma
Covers 1.5 million km2 western NA – outcrops in 13 states and 2 provinces of Ca Seasonally dry, especially in the south. Wetter and swampy (coal beds) in the north All kinds of plants and animals – conifers, ginkos, cycads, horsetails, frogs, fish, salamanders, pteros, mammals, dinos, probably mostly from riparian areas. Perennial water sources even in arid areas. Huge are of deposition shows what the right environment can do. Stan has collected Triassic horsetails from N AZ that were from plants 50 feet tall. Talk about Tucson’s old high water table. Climate reconstruction from paleosols. Certainly great dino finds to be made in AZ’s underexplored Morrison (res).

Morrison dinos – Camarasaurus, Allosaurus, many

The evocatively titled Hell Creek Formation (67-65 million years old) of the northern Great Plains is a mixture of deltaic sub-environments including swamps, river channels, floodplains, shoreface deposits, tidal inlets, estuaries, and delta plains. The last of the non-avian dinosaurs lived during the time of its deposition, and pronounced global climatic changes were taking place. The Area - Badlands in the southwest corner of North Dakota consist of mudstones, shales, siltstones, and sandstones of Upper Cretaceous and Tertiary strata. Most famous among these is the Upper Cretaceous Hell Creek Formation. Usually considered to represent alluvial plain deposits, detailed investigation of the facies, trace fossils, and vertebrate fossils suggest another interpretation. During deposition of the Hell Creek Formation, Laramide uplifts were shedding tremendous volumes of sediments into foreland basins. The resulting progradation of fluvially-dominated deltas resulted in rapid sedimentary in-filling of shallow marine basins. The abrupt progradation of these deltas has been conventionally misinterpreted as a drop in eustatic sea level rather than an increase in basin-fill sediment supply. The mosaic of sub-environments recognizable in the Hell Creek Formation includes estuaries, tidal inlets, tidally-influenced fluvial channels, fluvial channels, alluvial plains, lacustrine basins, and coal swamps. All of these are components of a much larger delta that was probably of a scale similar to the modern Mississippi River Delta. Hell Creek Formation

Hell Creek Formation Latest Cretaceous, 67-65 Ma
Montana, N and S Dakota, Wyoming K-T boundary, “fern spike” Rockies rising to west, huge amounts of sediment being shed into WIS, forming all kinds of great deposits – estuaries, tidal inlets, tidally-influenced fluvial channels, fluvial channels, alluvial plains, lacustrine basins, and coal swamps. Probably all related to a huge delta a la the Mississippi In the Hell Creek Formation, the boundary section that represents the transition from the Cretaceous period to the Paleogene is surprisingly thin (as well as being surprisingly unremarkable in it's overall appearance; a person who isn't a geologist would probably be unable to recognise it in the field). The duration of this period of change appears to have been short. In fact, new evidence bolsters the long-held belief that the change was sudden (Reference.: Mukhopadhyay, S., K. A. Farley, and A. Montanari A Short Duration of the Cretaceous-Tertiary Boundary Event: Evidence from Extraterrestrial Helium-3. Science 291: ) The so-called 'boundary bed' (see illustration) is (quoting from Retallack, 1996) "2 centimeters thick, pink to white, kaolinitic, micro-spherulitic, and vuggy". It appears to represent a highly acid-leached layer from impact-caused air-fall shortly after the impact. Retallack (1996) says "...it is now regarded as an early-settling fraction of altered ejecta from bolide impact....it's distinctive kaolinitic composition requires reaction with acid...." Retallack believes that this leached layer is a result of acid-rain that was produced by the impactor (bollide) hitting anhydrite target rock at Chicxulub1, Mexico. Anhydrite rock (a form of dehydrated gypsum) produces sulfur dioxide when vaporized. When sulfur dioxide mixes with atmospheric water, it creates sulfuric acid. The subsurface of the Chicxulub area is rich in anhydrite rock (Brett, 1992). Overlying the "boundary bed" is another impact-related layer (the so-called "impact bed"; see illustration). Quoting from Retallack (1996), the 'impact bed' is "one centimeter thick, gray, smectitic, and layered, with shocked quartz and an iridium anomaly." This layer is not acid-leached as the underlying layer was, and it probably settled-out of the atmosphere over a longer period of time, thereby avoiding the prolonged effects of acid-rainfall. Overlying the 'impact bed' is a layer of low-grade coal (called lignite), which represents quiet-water deposition, possibly in a swamp, a shallow lake, or an oxbow. Compared to the lower parts of the Hell Creek Formation, the roughly 10 centimeters of rock and lignite that overly the impact bed contain an unusually large amount of fossil fern spores (which, according to paleobotanist Kirk Johnson, comprises 90% of all surviving flora). The scientific literature refers to this sudden increase in fossil fern spore abundance as the "fern spike". In modern environments that have experienced forest fires, fern "blooms" are often the first re-colonizers in the devastated area. From the illustration above, note that the very top of the Hell Creek Formation is Paleocene in age, not Cretaceous. This rock formation boundary is, for all practical purposes, arbitrary, and was defined in the early part of this century as "the lowest persistent bed of lignite" that is above the highest in-place dinosaur (Calvert, 1912; Brown, 1952). Once a definition of a formation boundary has been published, it becomes authoritative and has priority. Only in recent years has it been discovered that the Cretaceous-Tertiary boundary (a time boundary) does not coincide exactly with the Hell Creek Formation-Tullock Formation boundary (a rock boundary). Depending on where you look, the stratigraphic distance (vertical thickness) between the iridium anomaly and the lignite layer can vary from as little as a couple of centimeters to over a meter. In most places, the iridium anomaly is entirely absent. Paleocene erosion of the iridium-containing boundary clay layer is probably the most likely culprit, although the effects of burrowing animals (called "bioturbation") during the earliest Paleocene also could destroy any sign of the clay layer. Further complicating the stratigraphic picture is that this "basal" lignite is not found in all places where the K-T boundary exists. And in some cases, the "lowest persistent lignite" occurs below the the K-T boundary. In North Dakota, there is one instance of a Triceratops skeleton occuring in the overlying Fort Union Formation (Johnson et al.), however, the fossil was still 1.4 meters below the K-T boundary. This means that the "lowest persistent lignite" bed cannot be used as a reliable indicator of the position of the K-T boundary. It is, however, an excellent criterion for recognizing the contact between the Hell Creek Formation and the overlying Tullock ("Fort Union") Formation.

So what’s it like to hunt for dinos
So what’s it like to hunt for dinos? Some days fossil hunting can be like this.

So how do I find a dinosaur?
Get a geologic maps Colors represent a combination of age and type of rock exposed at surface Find an outcrop on non-marine, Mesozoic sedimentary rocks, go there Put this on the test.

Geologic Map of Arizona
So how do I find a dinosaur?

Clades: how we think about relatedness in this class
Derived character: a feature of an organism that has changed from the ancestral condition. “Evolutionary novelties” Primitive character: a feature of an organism that has not changed from the ancestral condition Clade: a group of organisms that share derived characters A clade is a group of organisms that are more closely related to each other than they are to any other organisms last bit of background info before we start doing the dinosaurs. Go over a lot of examples. An evolutionary novelty or derived character arises in a species, and then all of its descendent species have that novelty and so can be grouped into a “clade”. Caveats: novelties can change, convergence – two or more lineages independently evolve similar novelties. For instance, upright posture in dinos and mammals. Can be distinguished by careful analysis of the bones. Another e.g. that we will look at in detail later is flight in pteros, birds, and bats. Wing structures very different.

Need all these together. AM ankle shared with pteros
Need all these together. AM ankle shared with pteros. Three pelvic bones make up the pelvis. In dinos, these fit together so that there is a big hole for the ball of the femur, allowing the legs to be under the body. These features that allowed dinos to stand upright and walk with their legs underneath their bodies are really what made dinos dinos because it allowed for their high activity levels. Add slide about lung metabolic constraint from Cowen, if still valid. Dinosaurs are the only animals that share all of these derived characters (and some more) so this makes them a clade. Birds have these same features, but some of them have continued to change and are now much more derived (hands are now part of wings).

Dinosaur “A reptile-like or bird-like animal with an upright posture that spent its life on land” Evolutionary novelties (shared derived characters): advanced mesotarsal ankle, femur with ball, pelvis with hole for femur ball. Allowed upright posture with legs under the body, not sprawled to side. This allowed high levels of activity! Three of more pelvic (sacral) vertebrae Upright posture allowed for more efficient breathing. Sprawling gate is always cramping one of the lungs when running or walking. Long thought that no sprawling reptiles could breath while moving, but recently found that crocs use pelvic motion to force air in and out when walking, monitor lizards use specialized throat muscles to gulp air. Still, probably nothing compared to the efficiency of a bird, mammal, or dinosaur.

Phylogenetic tree = family tree
Younger Time → In the phylogenetic tree, the closer the branches are too each other (as measured by the branching off point), the more closely related to each other they are. Lower on the diagram is older, higher is more recent. This is not the best diagram from the point of view of time Older Phylogenetic tree = family tree

Today – 1/18 Critter in the news / weather report Reading background

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Today – 1/18 Critter in the news / weather report Reading background

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Presentation on theme: "Today – 1/18 Critter in the news / weather report Reading background"— Presentation transcript:

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