Lab 12: Mesozoic B Observations How This Lab Will Work 1. Open a Word doc or similar on your computer 2. At various points I will ask you to answer a question based on the activities in this lab. 3. I will indicate these points by this symbol: Please answer these questions in your Word doc. 4. After you have assembled the answers into your Word doc, go to the course Canvas page. 5. On the module for this week there is a link to TurnItIn. 6. Please upload your document using the TurnInIt. 7. That completes the lab assignment. :) Topics Today: 1. Phylum Chordata: Hadrosaurs 2. Phylum Chordata: Therizinosaurus claw 3. Phylum Chordata: Therizinosaurus 4. Phylum Chordata: Tyrannosaurus rex tooth 5. Phylum Chordata: Velociraptor 6. Phylum Chordata: Deinonychus 7. Phylum Chordata: Utahraptor 8. Phylum Chordata: Spinosaurus Phylum Chordata: Hadrosaurs The Hadrosauridae were large herbivorous herd animals of the late Cretaceous. These are sometimes called “duck bills,” because of the duck-like shape of their mouths. They were also known for large crests on their heads, the purpose of which is contentious. Some claim these head structures could have been used for vocalizations. Read this about them from the UCMP: https://ucmp.berkeley.edu/diapsids/ornithischia/hadrosauria.html https://sketchfab.com/3d-models/parasaurolophus-walkeri-1fd82baa09584cc182ffbb4bd6262cad https://sketchfab.com/3d-models/young-maiasaura-skull-b8c1443629364d19a7c454efd3af47fa https://sketchfab.com/3d-models/dinosaur-skin- impression-1d95213d5ed94f8dbab77e2a61252074 Geology 121 Lab 12: Mesozoic B, page 1 of 6 https://sketchfab.com/3d-models/edmontosaurus-jaw- fragment-3c7cee8c9cf24e68b7db2a63a584f36f 9. What is an outlandish proposal for their head crest? _____________ 10. Could they swim? Why/why not? ____________________ 11. Looking at the Maiasaurus skull, what about it suggest the name “duck bill”? _____________ 12. Looking at the skin impression, what living animal does this most resemble? ______________________ 13. Looking at the tooth fragment, what does the shape of the teeth suggest about their diet? _________________ Please answer these questions in your Word doc. Phylum Chordata: Therizinosaurus claw The place to start is to ask what “therizo” means. It means scythe. https://sketchfab.com/3d-models/therizinosaurus-cheloniformis- ae046fe64b2a48f2b9d51efb96bf22cc 14. What does this claw look like to you? How might it have been used? _____________ It’s hard to get a sense of scale here from just this claw, so let this help: 15. Judging from this diagram, how long were their claws? _____________ Please answer these questions in your Word doc. Geology 121 Lab 12: Mesozoic B, page 2 of 6 Phylum Chordata: Therizinosaurus These were huge, truly frightening animals are known for their claws, said to be the longest known animal claws. These “scythes” look ready to kill giant prey… however, the truth may not be as straight-forward as that. https://sketchfab.com/3d-models/therizinosaurus-1c4497e339f64f0a96b2e923e85e9147 http://museum.wa.gov.au/explore/dinosaur-discovery/therizinosaurus 16. What did they eat? ____________ 17. How two things might they have used their unusual claws? __________ , ___________ Please answer these questions in your Word doc. Phylum Chordata: Tyrannosaurus rex tooth While therizinosauruses were herbivores, T. rex were definitely meat eaters. But were they hunters who stalked their prey? Or merely scavengers? Let’s look at a tooth: https://sketchfab.com/3d-models/tyrannosaurus-tooth-dant- tyranosor-69c7a7be73c44893972bb8a10a123c5d https://www.livescience.com/51672-theropod-serrated-teeth.html https://www.si.edu/newsdesk/factsheets/tyrannosaurus-rex 18. This first example shows seeming “cracks” in the tooth. But after reading the second article, what might these cracks have represented? _____________ 19. According to the article, did T. rex have serrated teeth, like a steak knife?? _________________ Please answer these questions in your Word doc. Geology 121 Lab 12: Mesozoic B, page 3 of 6 Phylum Chordata: Velociraptor Ok, everybody loves velociraptors because of that movie, so let’s take a look: https://sketchfab.com/3d-models/velociraptor-mongoliensis-skeleton- aa80c819afb04934834069618180cecb https://sketchfab.com/3d-models/velociraptor-mongoliensis- skull-4a1551d6fedc47ccbc82bdb1a346f814 20. What is the structure of the tail telling you? Does it look like it could flex its tail? _____________ 21. What do you make of the length of the arms compared to the rest of the body? How does that contrast with T. rex? _________________ 22. Zoom inside the skull and take a look at the teeth from the perspective of where the tongue would be. What can you say about the curvature of the teeth that might have helped velociraptor hunt its prey? _____________ 23. In? _________________ Please answer these questions in your Word doc. Phylum Chordata: Deinonychus As I said in lecture, that movie used velociraptors because the name sounded cool, butn velociraptors were turkey-sized. The animal really portrayed was probably meant to be: https://sketchfab.com/3d-models/deinonychus-velociraptor-claw- ba0ed7ec94e84af385cca0cb425fe5f1 https://sketchfab.com/3d-models/deinonychus-decimated-8d0bc8afae2b4b0d9094a9e564fd5377 https://sketchfab.com/3d-models/deinonychus-69977bfadc214496835a9a34d8f2e92c https://www.smithsonianmag.com/science-nature/you-say-velociraptor-i-say- deinonychus-33789870/ 24. Describe how the claws might have been used to kill prey? _____________ Geology 121 Lab 12: Mesozoic B, page 4 of 6 25. Align its head so that you are looking it right in the face. Can you see its two eyes, and can they see you? How might this “binocular vision” have been useful when hunting prey? (Hint: we use binocular vision during activities such as driving car) _________________ Please answer these questions in your Word doc. Phylum Chordata: Utahraptor In addition to Deinonychus, another more recent raptor would have even better fit the description of that movie. https://dinopedia.fandom.com/wiki/Utahraptor https://sketchfab.com/3d-models/utahraptor-skeleton-3aba8c3fd175480b89f87252c53854bf https://sketchfab.com/3d-models/utahraptor-block-north-f91ce89db4f644a38980d862e188c3a2 26. What is a difference compared to Deinonychus? _____________ 27. What does the fossil block suggest to you in terms of the difficulty of studying such fossil specimens? _________________ Please answer these questions in your Word doc. Geology 121 Lab 12: Mesozoic B, page 5 of 6 Phylum Chordata: Spinosaurus Well, we can’t leave the Cretaceous without talking about Spinosaurus, which was surely one of the most bizarre and frightening animals of the time. https://www.nationalgeographic.com/science/2020/04/first-spinosaurus-tail-found-confirms- dinosaur-was-swimming/ https://sketchfab.com/3d-models/spinosaurus-skeleton-ver-2018-by-vi- models-6081bdb0e8ce4096a8d3258c008a5471 https://sketchfab.com/3d-models/spinosaurus-4f2332ee93874d59a55fb60ed2873ec2 28. What distinction in terms of size/diet does Spinosaurus have? ___________ 29. How did this animal live and hunt? _____________ 30. What are some suggestions about the purpose of the huge spinal bones? _____________ 31. If this was a aqueous ambush hunter, in the same manner as a modern alligator, how might the back sail have not helped it hunt? ______________ 32. What was weird about its tail? _________________ Please answer these questions in your Word doc. Geology 121 Lab 12: Mesozoic B, page 6 of 6 .