Big Questions Did whales once live on land? How are birds and dinosaurs related? Why do we study fossils? What do fossils tell us? In what ways do fossils support the theory of evolution? 1

What are fossils? Fossils are the preserved remains or evidence of once living organisms. 2

How do fossils form? Fossils form when the evidence or parts of the organism are preserved after death. Usually soft parts are eaten or decomposed and hard parts are too scattered to form useful fossils. 3

What kinds of fossils are there? Trace Fossils: these fossils show evidence of an organisms behavior or movement. Foot prints, nests, teeth marks are trace fossils. Why do you think these types of fossils would be useful? 4

What kinds of fossils are there? Mineralization Fossils: these fossils are formed when the body is buried under mud or sand in a stream. Minerals replace the original material and harden into rock. Most of these fossils are from bone or shell but wood can also be mineralized. Why do you think these types of fossils would be useful? 5

What kinds of fossils are there? Carbonization Fossils: these fossils form when a dead organism is compressed over time and all the liquid and gas is driven out. The only thing left is a carbon outline or film of the organism. Why do you think these types of fossils would be useful? 6

What kinds of fossils are there? Mold Fossils: these fossils are formed when an organisms shell or bone makes an impression in the mud which then hardens. A mold of the organisms' external features is left behind. Why do you think these types of fossils would be useful? 7

What kinds of fossils are there? Cast Fossils: these fossils are formed sediments fill in a mold fossil and harden. A cast or copy of the organisms' external features is left behind. Why do you think these types of fossils would be useful? 8

What kinds of fossils are there? Original Material Fossils: these fossils are formed when an organism is trapped in ice, tar or amber. This prevents the soft tissue form decaying. Frozen mammoths and insects in amber are original material fossils. Why do you think these types of fossils would be useful? 9

What is the fossil record? There are many different types of fossils and they all give different types of information. Together, all the fossils found make up the fossil record. The fossil record gives us evidence of how living things have changed over time. 10

What is the fossil record? The fossil record is incomplete. There are gaps due to the difficulty in forming fossils and the fragility of existing fossils. However, there is sufficient evidence to support the theory of evolution (organisms changed over time and current species evolved from earlier species) 11

Examples of Timelines Following are some examples of evolutionary timelines. As we study them, consider how these organisms changed. Were the changes quick or slow? Do the changes support the theory of evolution? Why or why not? 12

Example 1 What do you notice in the picture below? Which limb is oldest? How do they change over time? 13

Example 1 The picture below shows changes in the forelimb (fin to foot) as fish evolved into tetrapods. 14

Example 2 What do you notice in the picture below? Which organisms are represented? How do they change over time? Does this evidence support the theory of evolution? How? 15

Example 2 The picture below shows a small predatory dinosaur, several types of archeopteryx and a modern bird. Can you see the similarities and changes to the skeletons as time passes? 16

Example 3 Groups Pakicetus Ambulocetus Maiacetus Dorudon Balaena ~55 mya Ambulocetus ~50 mya Maiacetus ~45 mya Dorudon ~40 mya Balaena ~30mya-now 17

Example 4 Independent 18

Image Credit Slide 4 – labeled for reuse, courtesy of Wikimedia https://upload.wikimedia.org/wikipedia/commons/thumb/7/7a/Dinosaur_State_Park_(Rocky_Hill,_CT)_- _close-up.JPG/320px-Dinosaur_State_Park_(Rocky_Hill,_CT)_-_close-up.JPG Slide 5 – labeled for reuse, courtesy of Wikimedia https://upload.wikimedia.org/wikipedia/commons/f/f3/PetrifiedWood.jpg Slide 6 – labeled for reuse, courtesy of Flickr https://www.flickr.com/photos/jsjgeology/15359852239 Slide 7 – labeled for reuse, courtesy of Wikimedia https://commons.wikimedia.org/wiki/File:Aviculopecten_subcardiformis01.JPG Slide 8 – labeled for reuse, courtesy of Wikimedia https://commons.wikimedia.org/wiki/File:Acadoparadoxides_briareus_fossil_trilobite_(Middle_Cambrian;_Si di_Abdallah_ben_el_Hadj,_Morocco)_2_(15083893830).jpg Slide 9 – labeled for reuse, courtesy of Wikimedia https://upload.wikimedia.org/wikipedia/commons/c/c8/Spider_in_amber_(1).jpg Slide 13 & Slide 14 – labeled for reuse, courtesy of Wikimedia http://upload.wikimedia.org/wikipedia/commons/2/23/Fishapods_tetrapods.JPG Slide 15 & Slide 16 – “Compsognathus” labeled for reuse, courtesy of Wikimedia https://upload.wikimedia.org/wikipedia/commons/9/97/Compsognathus_longipes.jpg “Archaeopteryx” labeled for reuse, courtesy of Wikimediahttps://upload.wikimedia.org/wikipedia/commons/thumb/5/55/Archaeopteryx_skeletals.jpg/600px- Archaeopteryx_skeletals.jpg “Bird Skeleton” labeled for reuse, courtesy of Wikimedia https://upload.wikimedia.org/wikipedia/commons/thumb/8/8f/Processus_uncinatus.png/220px- Processus_uncinatus.png Slide 18 – “Equine Evolution” labeled for reuse, courtesy of Wikimedia https://commons.wikimedia.org/wiki/File:Equine_evolution.jpg#/media/File:Equine_evolution.jpg; “Evolution of the Horse” labeled for reuse, courtesy of Wikimedia https://commons.wikimedia.org/wiki/File:Horseevolution.png#/media/File:Horseevolution.png

Image Credit cont. Slide 17 – “Pakicetus” labeled for reuse, courtesy of Wikimedia https://upload.wikimedia.org/wikipedia/commons/thumb/3/34/Pakicetus_BW.jpg/220px-Pakicetus_BW.jpg “Ambulocetus” labeled for reuse, courtesy of Wikimedia https://upload.wikimedia.org/wikipedia/commons/thumb/e/e6/Ambulocetus_BW.jpg/220px- Ambulocetus_BW.jpg “Maiacetus” labeled for reuse, courtesy of Wikimedia https://upload.wikimedia.org/wikipedia/commons/9/92/Maiacetus_NT.jpg “Dorudon” labeled for reuse, courtesy of Wikimedia https://upload.wikimedia.org/wikipedia/commons/thumb/8/81/Dorudon_BW.jpg/220px-Dorudon_BW.jpg “Bowhead Whale” labeled for reuse, courtesy of Wikimedia https://upload.wikimedia.org/wikipedia/commons/thumb/6/6c/Balaena_mysticetus.jpg/220px- Balaena_mysticetus.jpg “Pakicetus Skeleton” labeled for reuse, courtesy of Wikimedia http://upload.wikimedia.org/wikipedia/commons/e/e8/Pakicetus_fossil.png “Ambulocetus Skeleton” labeled for reuse, courtesy of Wikimedia https://upload.wikimedia.org/wikipedia/commons/7/70/Ambulocetus_fossil_remains.JPG “Maiacetus Skeleton” labeled for reuse, courtesy of Wikimedia https://upload.wikimedia.org/wikipedia/commons/e/e6/Maiacetus_inuus-lateral.jpg “Dorudon Skeleton” labeled for reuse, courtesy of Wikimedia https://upload.wikimedia.org/wikipedia/commons/5/5a/Dorudon_atrox-lateral.jpg “Bowhead Whale Skeleton” labeled for reuse, courtesy of Wikimedia https://upload.wikimedia.org/wikipedia/commons/5/5c/GreenlandWhaleLyd3.jpg