EART 65 Spring 2008 EXAM 2 REVIEW SHEET To prepare for the upcoming exam in EART 65 you should: What to bring? 1. A scantron test form (#F1712: ‘big pink one’) and a Number 2 pencil 2. One 8.5x11” sheet on which you can use one side to write notes. Other Issues 1. Review your lecture notes. The test will cover material from the lecture on 4/24/08 up to and including the material on Ornithopods on 05/13/08. 2. Review the relevant text chapters (including figures and cladograms). 3. Review the section assignments and quizzes for these weeks. The test will include bone identification questions that flow from your work over the last two weeks in section. 4. Make sure you can read and manipulate cladograms. There will be questions on this subject, just like on the last exam. 5. Look over the review sheet and make sure you can answer questions and know the importance of different terms. 6. Don’t forget the geologic time scale!! 7. Do not bring electronics to the exam. No iPods, cellphones, etc. If you are spotted using such a device during the exam, your exam will be confiscated. 8. There will be no makeup exams. Show up and take the exam, or give me the name of your doctor who will vouch for your absence. 9. The test will be one hour long. Class will continue after the exam, though we’ll only be checking out a video on Cretaceous animals. 10. Don’t forget the geologic time scale!! 11. The test will have ~50 questions. ***Note: There will be diagrams and cladograms on the exam so don’t forget to review visuals. BASIC ANATOMY There will be a figure on the exam, with lines pointing to bones. You will need to pull the name for those bones from a list (matching exercise). I will also expect you to know the major anatomical direction (anterior, posterior, dorsal, ventral, etc.) Below, SDC means Shared Derived Characters. GC means General characters that relate to the ecology of the animals. 1 SAUROPODOMORPHA Sauropodomorpha: SDC: Small head, long neck, elongate peg-like teeth, large thumb with claw, long femur, large foramen in pubis; GC: all are herbivores Prosauropoda: SDC: whopping big thumb claw, elongate neck vertebrae GC: gastroliths, quadrupeds, and facultative bipeds, these are the earliest diverse and abundant group of plant-eating dinosaurs, which presumably evolved from bipedal meat eaters. Late Triassic through Early Jurassic, Global distribution (Pangean) Sauropoda: SDC: (accumulate along base of cladogram) up to Neosauropoda Shortened skulls, rounded snout, lower temporal opening beneath the orbit, 12+ cervical vertebrae, pleurocoels, uniformly large, massive and solid limb bones long tails, five fingers/toes on each appendage GC: Include the largest land animals of all time (7 – 45 m) Camarasauromorpha: SDC: Large external nares, relatively long forelimbs GC: some with bifurcate neural spines (horizontal neck posture) Brachiosaurids: SDC: very long front legs, 13 elongate cervical vertebrae (non- bifurcate neural spines), neck joint vertically oriented, distinctive snouts, vaulted brows Titanosauria: SDC: osteoderms, very robust radius and ulna, long, broad snouts, nostrils high on head, pencil-like teeth at the very front of the jaws, very long necks Diplodocoidea: SDC: Peg-like teeth, 12+ cervical vertebrae with bifurcate neural spines (neck horizontally oriented), at least 80 caudal vertebrae, odd chevron in mid-tail region, elongate sub-rectangular snout, external nares fully retracted to top of the head When did prosauropods and sauropods first appear in the fossil record? When was each group most common? What was the geographic range of these two major groups? Did the ranges change dramatically through time? What are some lines of evidence for and against the idea that sauropods used their tails to generate sound? Are sauropods found in bone beds? Are they typically found as complete skeletons? What evidence type of evidence has disproved the old idea that sauropods were obligated to inhabit aquatic habitats so water could support their great bulk? Did sauropods and prosauropods feed close to the ground or high above it or both? If high, how did they reach up into the tree? How did sauropods process their food? Gastroliths? Gut fermentation? Oral processing? What are some of the challenges of being large, like a huge sauropod dinosaur? What are some of the advantages? What kind of evidence suggests that sauropods were gregarious, and may have traveled in herds? Are nests known for sauropod dinosaurs? Is there evidence for parental care? Did sauropods have a high or a low EQ? 2 ORNITHISCHIAN INTRO Ornithischia: GC: all are herbivores Many SDC: 1. back-prong on pubis, 2. long, thin forward process on ilium, 3. at least five sacral vertebrae, 4. ossified tendons around sacrum, 5. predentary = unpaired, scoop-shaped bone at front of lower jaw, 6. toothless tip of snout with "beak", 7. small, triangular teeth, 8. jaw joint set below level of the upper tooth row Fabrosaurids: GC: small bipedal, primitive ornithischians, includes Pisanosaurus: upper Triassic and Lesothosaurus: lower Jurassic: least derived, well known ornithischian Genasauria: SDC: reduced mandibular foramen, muscular cheeks Cerapoda: SDC: diastema between premaxilla and maxilla, 5 or fewer teeth on premaxilla, finger-like projection (trochanter) on the femur Ornithopoda: see notes below Marginocephalia: see notes below Two main groups - Pachycephalosaurs and Ceratopsians Thyreophora: SDC: Dermal armor (keeled scutes on dorsal surface) Scutellosaurus: primitive thyreophoran, small biped Scelidosaurus: primitive thyreophoran, larger quadruped Eurypoda: SDC: enlarged anterior ilium, short ilium behind hip socket, stocky foot/hand bonesk new bones around the eye Two main groups - Stegosauria and Ankylosauria STEGOSAURIA Stegosauria: SDC: Rows of osteoderms over the body that developed into spines and plates, Parascapular spines over shoulder blade, spikes on tail, loss of ossified tendon, body sloped forwards due to short front legs, very tall neural arches on thoracic vertebrae, feet with broad hooves, solid box-like skulls GC: 3-9 meters long, 300-6500 kg (to over 7 tons) What did stegosaurs appear and disappear from the fossil record? When were they most common? What was the geographic range of stegosaurs? Did it change dramatically through time? Are stegosaur specimens commonly well preserved? If not, what are some ideas about why they are poorly preserved. What kind of habitats did stegosaurs frequent? What are some ideas about the function(s) of the plates and spines of stegosaurs? What is some evidence in support of these different ideas? Are the ideas mutually exclusive? What factor makes it difficult to imagine that stegosaurs could move fast? How might they have overcome this limitation when moving slowly? Did stegosaurs feed close to the ground or high above it or both? How might they have reached high? How did stegosaurs process their food? Gastroliths? Gut fermentation? Oral processing? How do we obtain information on brain size in dinosaurs? How large were stegosaur brains (absolutely and relatively, i.e., in ounces and EQ)? What part of the stegosaur brain was largest? How did stegosaurs manage with such small brains? Did they have a “hind” brain (evidence for and against)? 3 ANKYLOSAURIA, WAYS TO BE AN HERBIVORE, HOW TO WEIGH A DINOSAUUR Ankylosauria: SDC: low skull, loss of antorbital and upper temporal fenestrae, body armor fused to lower jaw, long sacrum, flaring blades on the ilium, broadly arched ribs (wide gut cavity), closed hip socket, reduced pelvis (extreme reduction of pubis), dense dorsal shield of osteoderms, some modified to spines and/or tail clubs. GC: Encased in shell-like bony armor made of interlocking osteoderms, bodies beneath the armor were flat and broad, housing large gutsm, triangular-shaped teeth strong cheeks, some evidence of chewing (oral processors), rarely over 5 m long ad 3-4 tons, fore limbs relatively short with hindlimbs 2x the length of forelimbs Nodosauridae: SDC: Narrow skulls, Skull osteoderms large, few, and symmetrical, more rigid armor and tails than ankylosaurids, spines in shoulder/neck region, no tail clubs or 'horns' on skull Ankylosauridae: SDC: very wide skulls covered with small, asymmetrical osteoderms, yes extremely posterior, ‘horns’ at back of skull, tail club, tails had light armor for maximum flexibility, bony secondary palate What did these two groups of ankylosaurs appear and disappear from the fossil record? When were they most common? What was the geographic range of these two groups of ankylosaurs? What kind of habitats are ankylosaurs found in? What is bloat and float preservation? How fast were ankylosaurs? Did ankylosaurs have erect or sprawling limb posture? Did ankylosaurs feed close to the ground or high above it or both? How did ankylosaurs pluck vegetation off plants? How did nodosaurid and ankylosaurid feeding differ? How did ankylosaurs process their food? Gastroliths? Gut fermentation? Oral processing? How did ankylosaurs thermoregulate? What are turbinates? How did ankylosaurs defend themselves? How did they engage in offense? How large were ankylosaur brains (in EQ)? Understand the different ways that animals may convert from carnivore to herbivore. What is the key problem facing herbivores? How do animals over come this? How are small picky animals different than large, indiscriminant animals? Be able to supply examples of both. Understand the different ways that we estimate the weight of dinosaurs (scale replica approach and relationships between leg area and mass). Why does the cross-sectional area of the leg increase in dimensions faster than the length of the leg, or length of the dinosaur? I.e., why is it getting larger “stressful”. What is stress and what is strength, and how do both increase with size of the animal? How do animals get large without breaking their legs? 4 MARGINOCEPHALIANS: PACHYCEPHALOSAURS AND CERATOPSIANS Reminder: Marginocephalians are ornithischians and genasaurians, but on a different evolutionary branch (cerapoda) than stegosaurs and ankylosaurs (thyreophoran eurypods).