Fossils Sci. 3.1

Fossil: Preserved remains or traces of living things Only in sedimentary rock Can tell how, when, and where a thing lived From Latin fossus “having been dug up”

Question 1 1a. What kind of rocks are fossils found in? igneous, metamorphic, sedimentary, all of the above 1b. Fossils can tell what about a living thing? Where it lived, how it lived, when it lived, all of the above 1a. What kind of rocks are fossils found in? igneous, metamorphic, sedimentary, all of the above 1b. Fossils can tell what about a living thing? Where it lived, how it lived, when it lived, all of the above

Conditions must be just right Usually a quick burial in sediments Protected from scavengers, microorganisms, etc… Most organisms do not end up being fossils

Question 2 2a. It is not very likely that an individual organism will become a fossil. T/F 2b. If an organism is not quickly buried in sediments: scavengers can tear it up, waves can destroy it, microorganisms can cause it to decay, all of the above 2a. It is not very likely that an individual organism will become a fossil. T/F 2b. If an organism is not quickly buried in sediments: scavengers can tear it up, waves can destroy it, microorganisms can cause it to decay, all of the above

Hard parts More likely to be fossilized

Question 3 3a. Which part of an octopus would most likely become a fossil? Tentacles, beak, head, all of the above 3b. Which type of animal would you be more likely to find fossils of? Snails with shells, slugs without shells, worms, leeches 3a. Which part of an octopus would most likely become a fossil? Tentacles, beak, head, all of the above 3b. Which type of animal would you be more likely to find fossils of? Snails with shells, slugs without shells, worms, leeches

Permineralized remains Minerals replace original (partially or completely) Petrified wood, process by which porous spaces in the shell, wood, or bone are filled with minerals (often silica). Sometimes some of the original material remains encased in the mineral. The minerals filling the void spaces are carried in solution within groundwater moving through the sediment/ sedimentary rocks the fossils are buried in. Permineralized or petrified wood is most common in sediments also containing volcanic ash because the ash provides a source of silica to permineralize the wood.

Question 4 4a. In some permineralized fossils, none of the original material that made the organism is left. T/F 4b. In some permineralized fossils, some of the original material that made the organism is encased. T/F 4a. In some permineralized fossils, none of the original material that made the organism is left. T/F 4b. In some permineralized fossils, some of the original material that made the organism is encased. T/F

Carbon films Left over C forms a silhouette All living things contain carbon, hydrogen, oxygen, and nitrogen. Heat and pressure cause volatilization of H, O and N, leaving C behind. Good type of fossil for showing soft parts of an organism

Question 5 5a. A carbon film fossil is a three dimensional version of the original organism. T/F 5b. Carbon film fossils often show details of the soft parts of an organism. T/F 5a. A carbon film fossil is a three dimensional version of the original organism. T/F 5b. Carbon film fossils often show details of the soft parts of an organism. T/F

Coal C from prehistoric plants

Question 6 6a. Coal is mainly what’s left over from prehistoric plants. T/F 6b. Coal formation takes a great deal of: time, pressure, heat, all of the above 6a. Coal is mainly what’s left over from prehistoric plants. T/F 6b. Coal formation takes a great deal of: time, pressure, heat, all of the above

Mold Cavity left after organism has decayed

Cast A copy of original made of sediments or minerals

Question 7 7a. A cup cake pan is a: mold, cast 7b. A cup cake is a: mold, cast 7a. A cup cake pan is a: mold, cast 7b. A cup cake is a: mold, cast

Original remains Extremely rare Ex: amber, ice, tar Jurassic park

La Brea tar pits

Question 8 8a. The most common type of fossils are original remains. T/F 8b. In which situation could original remains be preserved for thousands to millions of years? An organism is: encased in tree sap, frozen in ice, tar, all of the above 8a. The most common type of fossils are original remains. T/F 8b. In which situation could original remains be preserved for thousands to millions of years? An organism is: encased in tree sap, frozen in ice, tar, all of the above

Trace fossils Footprints, trails, burrows Fossilized evidence of organisms’ activity. Would include dino dung. Can tell a lot about how an organism lived. Sauropod tracks, large on outside, shielding young.

Question 9 9a. Trace fossils can include actual remains. T/F 9b. Which kind of fossil is the preserved evidence of past activity? Permineralized, carbon film, mold/cast, trace 9a. Trace fossils can include actual remains. T/F 9b. Which kind of fossil is the preserved evidence of past activity? Permineralized, carbon film, mold/cast, trace

Index fossils Common species that existed for a short time

Question 10 10a. A good index fossil is of an organism that was: common/abundant, rare, not widely distributed 10b. A good index fossil is of an organism that: existed for a long time, existed briefly, lived in only specific places 10a. A good index fossil is of an organism that was: common/abundant, rare, not widely distributed 10b. A good index fossil is of an organism that: existed for a long time, existed briefly, lived in only specific places

Fossils describe ancient environments 310 mil. Years ago

Question 11 11a. What type of terrain was here 310 million years ago (when we were below the equator)? Swamps, deserts, deep seas, shallow seas 11b. Was this area above or below the equator 310Ma (Mega-annum)? Above, below 11a. What type of terrain was here 310 million years ago (when we were below the equator)? Swamps, deserts, deep seas, shallow seas 11b. Was this area above or below the equator 310Ma (Mega-annum)? Above, below