Fossil Identification Using the two fossils provided and the geologic map of Pennsylvania. 1.What types of rocks are the two samples? (igneous, sedimentary, metamorphic) Greenish-Brown Rock Sample 2.What type of organism is fossilized in this rock sample? 3.This rock sample was found on top of a mountain in Center County PA near Penn State. What is the age range of rock in Center County? 4.What type of environment did these organisms live in? 5.What does this tell you about the area where the fossil was found during the time when the fossil was alive? 6.How did this fossil and rock type get on top of a mountain in PA? Coal (Black Rock) Sample 7.What type of organism is fossilized in this rock sample? 8.The rock type is coal. What type of environment did this organism once live in? 9.Which county in PA could these fossils been found in? MontgomeryLancasterSchuylkillErie 10.How old would the fossils be if they were from this county?

Interpreting Fossil Prints When paleontologists study fossils they must often make inferences (educated guesses) about the events that produced the fossils they are studying. At this station you will work with sketches of a set of fossil footprints made by animals more than 100 million years ago Make FIVE observations (facts) about the fossilized footprints. Consider such factors as size, shape, and position of the footprints Make FIVE inferences (educated guess) about the prints that reconstruct the events that could have caused this pattern. There is more than one possible answer.

Transitional Species Also called common ancestors or missing links are searched for to show the evolutionary connection between species & how they change over time. Match the first appearance of each animal in the fossil record with its fossil. Archaeopteryx (birds)Coelophysis (dinosaurs)Tiktaalik (amphibian) A. afarensis (Hominid)reptilevertebrate

Relative Age Dating Answer the following questions using the diagram above. 1.Which letter represents the oldest rock layer? 2.What law explains your answer? 3.Provide TWO organisms that would be a good index fossil? 4.Briefly explain why they are good index fossils. 5.Which species would be the worst example of an index fossil? 6.According to the rock layers put the following animals in order of evolution (oldest to youngest). dinosaurbirdfishtrilobitemammal 7.Provide an example of an unconformity by its letter. 8.What could explain why there is no sedimentary rock layer “D” at site 2? 9.What type of rock is E, C, X & V? (igneous; sedimentary; metamorphic)

Unconformities & Relative Age Dating Matching

Unconformities & Relative Age Dating

Absolute Age Dating 1. Carbon-14 has a half-life of 5,730 years. You begin with 600 grams of Carbon-14 in a sample of bone. At the end of the first half-life, how many grams of Carbon-14 is still in the bone? 2. After 3 half-lives, how many grams of Carbon-14 are still in the bone? 3.If a radioactive rock has a half- life of 10,000 years and the sample that is being measured is only 12.5% radioactive (87.5% of the rock is stable) how old is the radioactive rock? Pb U U U U U U U UUU NCCC C C C N N NN NNN N N N N N N N N N N

Example of Radioactive Decay