GEOL 104 Dinosaurs: A Natural History Final Review Review Tests 1 & 2, especially: Definition of Dinosauria (the concestor of Iguanodon and Megalosaurus and all of its descendants) Proper taxonomic grammar! What are the relationships between dinosaurs and other tetrapods? What are the relationships between and important adaptations of the major groups of dinosaurs? (pay particular attention to those groups who were referred to again during the last third of the course!) Bird origins What are the major events in dinosaur history? Evolution & Cladistics (be able to read a cladogram) Geologic time Dinosaur Functional Anatomy & Behavior Significance of osteological correlates Methods of interpreting function & behavior: Analogies with living forms Phylogenetic distribution of behaviors Biomechanics Geological Evidence (tracks, coprolites, bite marks, etc.) Striding locomotion in dinosaurs Difficulty in determining top speeds (even for living animals) Use (and difficulties) of footprints in studying dinosaur locomotion Cursoriality vs. Graviportality: osteological correlates of each Scaling issues, allometry: isometry, negative allometry, positive allometry Which groups of dinosaurs have the most cursorial adaptations? Which the most graviportal? Changes of locomotion in eumaniraptorans: knee-driven striding Other types of functional analysis: bite force, balance, joint motion, hearing, smelling, vision Interspecific vs. Intraspecific Behavior Message of display: Defensive, Territorial, Sexual (courtship), Species Recognition Medium of display: Visual, Sound, etc. Examples of dinosaur behavior from the fossil record Why display? Gregarious behavior: evidence (direct and inferred); advantages to predators, to prey; disadvantages to living in groups; Kin Selection & Reciprocal Altruism Sexual strategies; sexual dimorphism Difficulties in determining sex of dinosaurs Dinosaur Eggs and Babies Altricial vs. Precocial Growth Dinosaur nests, clutches, and nesting patterns Evidence for parental care Evidence for baby dinosaurs in groups Changes in dinosaur growth (esp. appearance of species-level features in sub-adults) Skeletochronology & use of Lines of Arrested Growth How dinosaur growth compares to non-avian reptiles? To mammals? Dinosaur lifespans Life-history strategies: K-selected vs. r-selected Endothermy vs. Ectothermy “Warm-Blooded” “Cold-Blooded” Energy Source: Endothermy Ectothermy Metabolic Rate: Tachymetabolism Bradymetabolism Temperature over Time: Homeothermy Poikilothermy Resting vs. active metabolic rates; duration of sustained activity; recovery timeWhy evolve endothermy? Increased aerobic capacity, greater environmental tolerance, increased metabolic efficiency, help in parental care (pre- and post-natal) The Aerobic Equation (C6H12O6 + 6 O2 Æ 6 CO2 + 6 H2O + energy; or “glucose + oxygen yields carbon dioxide, water, and energy”). How to get extra glucose & oxygen? How to distribute extra glucose & oxygen to cells? How to get rid of extra carbon dioxide? Traditional Estimates of Dinosaur Physiology: Posture Latitudinal distribution Feeding adaptations (such as dental batteries) Relation to birds Predator-prey ratio Microscopic bone structure (Haversian canals, reworked bone) Insulation Small brain size Non-traditional Physiologies: Gigantothermy Heterometabolism (Ontogenetic and Behavioral) Respiration in Mammals vs. Crocs vs. Birds vs. other tetrapods. Belly-breathing in basal archosaurs (and at least some dinosaurs?). Air sac breathing with one-way lungs in at least Saurischia. Other variations of respiration (in Ornithischia, in Pterosauria). Function of four-chambered hearts, and evidence for such in dinosaurs. Nasal Turbinates, and significance of enlarged nares in bigger/more derived dinosaurs. Significance of higher oxygen and carbon dioxide levels, and higher plant productivity, in Mesozoic Other organisms of the Mesozoic and the K/Pg Extinction Be familiar with the following groups and their fate relative to the K/Pg Extinction: Marine life: Coccolithophorids; foraminiferans; ammonoids; belemnoids; rudists; inoceramids Mesozoic marine reptiles: Ichthyosaurs, plesiosaurs, hesperornithines, sea turtles, mosasaurs, marine crocodilians Terrestrial life: Plants, insects, amphibians, turtles, tuataras, lizards (incl. snakes), crocodilians (incl. various non-aquatic types), champsosaurs, pterosaurs Mesozoic mammals: Origins; diversity; monotremes, multituberculates, therians (eutherians (placentals and our ancestors) plus metatherians (marsupials plus their ancestors) Definitions: Extinction Mass extinction Maastrichtian Campanian Paleogene K/Pg extinction Hypotheses of extinction: What evidence exists for different agents of extinction? How might each have caused the event? Good evidence for: Volcanism: esp. Deccan Traps (India) Asteroid impact: Iridium layer at Gubbio, Italy Shocked quartz, melt glass, tsunami deposits, ejecta deposits, etc. Crater at Chicxulub (Yucatán) Maastrichtian Regression What is the environmental impact of each of those agents? The effects and timing of each? What does the magnetostratigraphic record say about the timing of Deccan Traps and the Chicxulub Impact? Phases of destruction from the Chicxulub impact: Phase I Shockwave & Tsunami; Phase II “Easy-Bake Oven”; Phase III Impact Winter; Phase IV Greenhouse Summer Changes in dinosaur populations (especially in western North America) before and at K/Pg boundary Pattern of fates at K/Pg in marine and continental environments Popular Culture Changing popular perceptions of Dinosauria Reconstructing dinosaurs from fossils Hunting for Dinosaurs Field techniques to collect fossils Importance of collecting data other than the bones themselves! In general What are dinosaurs? What are not