GEOL 104 Dinosaurs: A Natural History
Essays 1-3: Dinosaur Growth, Behavior and Physiology

DUE: Friday, Dec. 1

For each of these homework assignments (counted separately in terms of grades), answer in the form of a short essay (about one paragraph long each).  You don’t need to cite your sources (lectures, chapters in the textbook, etc.), nor do you need to use exact quotes, but the information must be factual.  In some cases you will have two or more possible paragraph essays to write: you get to choose which one you use.

Throughout, be VERY CAREFUL about your taxonomic grammar!!  Points will be taken off for lack of italics (or underlining, if you are writing by hand) for generic and specific names, or for using italics/underlining in non-generic or specific names.  Be careful of when to capitalize and when not to capitalize, as well.

Essay 1 Dinosaur Growth (use essay A or B)
Essay A)  Some Mesozoic dinosaurs seem to have been precocial (mobile from birth), and others altricial (nest bound).  Describe the evidence used to decide of a hatchling dinosaur was precocial or altricial (that is, what evidence would be used to show it was precocial vs. what evidence would suggest it was altricial).

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Essay B) In what way was the growth of dinosaurs from hatching to adulthood different from that of typical non-avian reptiles?  In what way was the growth of dinosaurs from hatching to adulthood different from that of modern placental mammals?

Essay 2 Dinosaur Behavior (use essay C, D, E, or F)
Essay C) Paleontologists use four main types of evidence to figure out the behavior of extinct animals: phylogenetic distribution of traits; broad analogies with modern animals; biomechanics; and geological (or other hard physical) evidence.  Explain what each of these types of evidence is, and give an example of each.

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Essay D) Sauropods were once thought to have been primarily aquatic, but very few modern paleontologists would take this concept seriously.  What evidence has been used to suggest that these dinosaurs could not have been snorkeling swamp-dwellers?

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Essay E) Both major clades of marginocephalians (Pachycephalosauria and Ceratopsia) contain members with anatomical specializations suggesting some form of direct intraspecific combat.  What specializations in Pachycephalosauria suggest such combat (give at least two examples)?  What specializations in Ceratopsidae (give at least two examples)?

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Essay F) Many dinosaurs show specializations which might have been some forms of visual (sight) and aural (sound) display structures.  Give at least two examples of possible visual displays, and two examples of possible aural display mechanisms, and indicate which dinosaurs possessed these.

Essay 3 Dinosaur Physiology (use essay G, H, or I)
Essay G) What are at least four (4) lines of evidence that suggest that non-avian dinosaurs were warm-blooded?  Explain how each line of evidence supports a warm-blooded model.

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Essay H) What are at least three (3) lines of evidence that suggest that non-avian dinosaurs were not warm-blooded?  Explain how each line of evidence supports a non-warm-blooded model.

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Essay I) Recent evidence suggests that non-avian dinosaurs had specialized ways of breathing and getting rid of heat.  Describe the anatomical features associated with these.