Mike Kozina SASS July 18, Dino Scienc e

What is a dinosaur? 2

That’s right—birds are now dinosaurs! 3

Types of Dinosaurs 4 Sauropods Theropods Marginocephalia Saurischia: Lizard-Hipped Ornithischia: Bird-Hipped NBA Players Thyreophorans Ornithopods

Dino Sizes 5 NameHeightLengthWeight Ankylosaurus (armored lizard) 7 ft. 2.1 m 35 ft m 10,000lbs 4,536kg. Apatosaurus (deceptive lizard) 15 ft. 4.5 m 75 ft m 66,000lbs 29,937kg. Argentinosaurus (Argentina lizard) 70 ft m 120 ft m 220,000lbs 99,792kg Brachiosaurus (arm lizard) 50 ft m 100 ft m 100,000lbs 45,360kg Compsognathus (elegant jaw) 2 ft. 0.6 m 3 ft. 0.9 m 8lbs 3.6kg Corythosaurus (helmet lizard) 16 ft. 4.9 m 30 ft. 9.1 m 8,860lbs 4,019kg Deinonychus (terrible claw) 5 ft. 1.5 m 9 ft. 2.7 m 175lbs 80kg Iguanodon (iguana tooth) 18 ft. 5.5 m 30 ft. 9.1 m 10,000lbs 4,536kg Seismosaurus (tremor lizard) 84 ft m 150 ft m 200,000lbs 90,720kg Stegosaurus (plated lizard) 11 ft. 3.4 m 30 ft. 9.1 m 6,000lbs 2,722kg Triceratops (three-horned face) 9.5 ft. 2.9 m 26 ft. 7.9 m 14,000lbs 6,350kg Tyrannosaurus (tyrant lizard) 23 ft. 7.0 m 50 ft m 14,000lbs.6,350kg Velociraptor (swift robber) 2 ft. 0.6 m 6 ft. 1.8 m 250lbs.113kg

Dino Sizes 6 NameHeightLengthWeight Ankylosaurus (armored lizard) 7 ft. 2.1 m 35 ft m 10,000lbs 4,536kg. Apatosaurus (deceptive lizard) 15 ft. 4.5 m 75 ft m 66,000lbs 29,937kg. Argentinosaurus (Argentina lizard) 70 ft m 120 ft m 220,000lbs 99,792kg Brachiosaurus (arm lizard) 50 ft m 100 ft m 100,000lbs 45,360kg Compsognathus (elegant jaw) 2 ft. 0.6 m 3 ft. 0.9 m 8lbs 3.6kg Corythosaurus (helmet lizard) 16 ft. 4.9 m 30 ft. 9.1 m 8,860lbs 4,019kg Deinonychus (terrible claw) 5 ft. 1.5 m 9 ft. 2.7 m 175lbs 80kg Iguanodon (iguana tooth) 18 ft. 5.5 m 30 ft. 9.1 m 10,000lbs 4,536kg Seismosaurus (tremor lizard) 84 ft m 150 ft m 200,000lbs 90,720kg Stegosaurus (plated lizard) 11 ft. 3.4 m 30 ft. 9.1 m 6,000lbs 2,722kg Triceratops (three-horned face) 9.5 ft. 2.9 m 26 ft. 7.9 m 14,000lbs 6,350kg Tyrannosaurus (tyrant lizard) 23 ft. 7.0 m 50 ft m 14,000lbs.6,350kg Velociraptor (swift robber) 2 ft. 0.6 m 6 ft. 1.8 m 250lbs.113kg

When did Dinosaurs rule the earth? 7

Dinosaur Motion/Mechanics How fast did dinosaurs go? How could they support such large bodies? Did land dinosaurs swim? 8

Similarity Simple scaling does not necessarily reproduce the same results 9 E.g.: Animal mass ~ bone volume; Bone strength ~ bone cross section  can’t just scale up

So, how can we relate big to small? 10

Other similarity terms you may have heard 11

12 Estimate speed of dinosaurs using: 1.Stride length (from footprints) 2.Hip height 3.Froude number for modern day mammals So, how fast? 1.Sauropods ~ 1m/s 2.Fastest tracks (from horse-sized biped) ~12m/s Problems: 1.Even for mammals scaling fails for small sizes because movement pattern very different 2.Footprints only tell velocity in certain types of terrain (those likely to have tracks saved)—not representative How fast could they run, and how do we know?

Other ways to estimate velocity Relate bone strength to general athleticism – E.g. Triceratops estimated to be in between elephant and rhino in speed Computer simulations: – Genetic algorithms search to extremize parameters such as energy consumption or speed – Some require knowing motion patterns  Can use constraints to eliminate impossible orientations 13

Some simulation results 14

Size Problems: How could Littlefoot grow so big? 15

What about blood flow? Open question Extremely robust hearts? Possibility that long necks never raised above ~30degrees? 16

Did dinosaurs swim? 17

Why did they die out? Hormonal problems leading to thin eggshells Volcanos put dust in the air blocking the sun Over predation by carnosaurs Slipped disks in vertebral column Blindness from cataracts Climate became 1.Too hot 2.Too cold 3.Too wet 4.Too dry Constipation Fluctuations in the gravitational constant, somehow affecting dinosaurs Radiation from a supernova Uranium poisoning 18

Really, why did they die out? Overwhelming evidence for asteroid colliding with the earth Sharp break in fossil type—K/T boundary High levels of iridium in soil Large crater in Chixhulub, Mexico 65.5 MYA Estimate size of asteriod ~10km diameter (since iridium at K/T found worldwide) 19

More evidence for asteroid impact Shocked quartz caused by impact Microtektites—bits of glass ejected from impact site 20

Dino-related Research at SLAC Use synchrotron to pick out different chemicals left in Archaeopteryx fossil Can link chemicals to pigment density 21

Selected Bibliography Dinosaur Diversity – Wang, PNAS (2006) Dinosaur Biomechanics/Motion – Sellers, Proc. R. Soc. B (2007) – Alexander, Scientific American, April 1991 – Alexander, Proc. R. Soc. B (2006) Sauropod Size Issues – Seymour, Biol. Lett (2009) – Sander, Science (2008) – Henderson Proc. R. Soc. Lond. B (Suppl.) 271 S180-S183 (2004) General Dino Stuff (includes all info I used about extinction) – Fastovsky, D. and Weishampel, D. Dinosaurs: A Concise Natural History. Cambridge University Press (2009) Dino research at SLAC – Bergmann, PNAS (2010) Similarity in other contexts (non-dino) – Landau, L.D. and Lifshitz, E.M. Fluid Mechanics: Course of Theoretical Physics Vol nd Ed. Butterworth-Heinemann (2010) – 22

23 Thanks for listening!