Final Exam Review Sheet For Geology 7

Final Exam Review Sheet for Geology 7 (Lectures 10-19 ONLY) General points: Make sure you know how all the taxa (see below) are related to each other (drawing one big cladogram will help). Know how to graph novelties onto a cladogram, and make sure you understand how to read cladograms. TAXA Be able to draw a cladogram indicating their relationships (note – some groups are nested within others). What groups do they contain, and what groups are they part of? Are they monophyletic or paraphyletic? For those with an *: what novelties distinguish them (see list of novelties below)? • Margin-Heads* *Novelty: Margin of bone at back of skull Two groups: Pachycephalosaurs and Ceratopsia • Pachycephalosaurs*-thick skulled lizards (dome heads) *Novelty: Thickened skulls (two types: flat heads and domed heads) Used for head pushing, not head butting in sexual competition bipedal, slow, ranged from large to small has a simple frill, just a lip of bone simple row of heterodont teeth large belly • Ceratopsians* - horned faces *Novelties: Rostral bone- beak-like bone High snout- nasal openings were large and situated high up More elaborate frill than Pachycephalosaurs *Novelties: of both Ceratopsids and Protoceratopsids: Large margin at back of skull (frill) Large size, quadrupedal Dental Batteries • Ceratopsids*-social animals • Protoceratopsids paraphyletic, smaller than ceratopsids. Lack horns • Saurischia*-lizard hipped dino Pubis points down and forwards, characteristic of other tetrapods also (ancestral character) *Novelties: Long neck Thumb offset from rest of hand, semi-opposable • Sauropodomorphs* (type of Saurischian) herbivorous, largest animals ever *Novelties: Thumb claw Extremely long neck Extremely small head with respect to body Very simple (peg-like) teeth • Prosauropods- early forms in late Triassic and Early Jurassic Not sure if it’s a separate clade Smaller body, dominating hind limb • Sauropods*-long necks

*Novelties: Stout, stump like limbs (think elephant feet), maintain offset, clawed thumb Short, distal limb bones- femur longer than fibia or tibia, humerus longer than ulna and radius Position of nostrils-migrate to top of head, between eyes, secondarily enlarged Three types of Sauropods- Diplodocids, Camarasaurs, Brachiosaurs ( each one gets bigger with respect to nostrils and forelimbs) • Theropods* (Type of Saurischian) ancestrally meat eaters Includes T. rex and birds *Novelties- Teeth like steak knives, point backwards, laterally compressed with serrated edges 1-2-3 hand, digit 5 lost, digit 4 vestigal Sharp claws on hand Splint-like fibula Hollow bones-much more extreme than in sauropodomorphs (easily broken, don’t fossil well) • Ceratosaurs (one main group of theropods) horned lizard, fairly primitive branch of theropods • Tetanurans* (one main group of theropods) stiff tail *Novelties- Stiff tails digit 4 completely lost Large hands for grasping Pubic boot • Carnosaurs (one main type of tetanurans) huge meat eaters Probably a paraphyletic group Hunted in large packs • Coelurosaurs* (one main type of Tetanurans) hollow tails *Novelties-ossified, fused clavicles Relatively long arms • Ornithomimids (Major group of coelurosaurs) No teeth (convergent with birds) • Tyrannosaurids (Major group of coelurosaurs) *Novelties-1-2 hands huge teeth for crushing bones Really tiny forelimbs • Maniraptors* (Major group of coelurosaurs) *Novelties-semilunate carpus (half-moon shaped wrist bone that allows wrist to be bent from side to side) Bowed ulna-bent bone in order to accommodate muscles that allow hand to be moved from side to side Highly stabilized tail-even stiffer than in Tetanurans Reverse pubis- (difference b/w Maniraptor and Ornithischia pubis is the maniraptors have the pubic boot • Dromaeosaurs* (type of maniraptor) *Novelties-enormous claw on toe 2 (had to walk on the other two toes) • Velociraptor (type of dromaeosaur) late Cretaceous of Mongolia *famous fossil of Velociraptor killing a Protoceratops • Birds* two main groups of birds today: Ratites-large flightless birds Everything else • Archaeopteryx- one of the earliest birds had wings, perching foot (like birds) and a long tail, bladelike serrated recurved teeth, hands with claws and metatarsals that weren’t fused (like many dinos)

• Synapsids- dominate late Paleozoic terrestrial realm, decline in the mid-late Triassic (archosaurs take over) • Mammals (only living synapsid today) originated in the late Triassic • Monotremes (type of mammal) characterized by laying eggs, young lick the milk secreted from mother’s pores onto her hair Platypus, echidna • Placentals (type of mammal) characterized by young developing longer in the uterus (born pretty well developed), no pouch, milk from nipples *key novelty= placenta-organ that provides nutrients, oxygen and removes waste Most diverse group of mammals- cats/dogs, cows, whales, rodents, primates • Marsupials (type of mammal) characterized by no eggs, live birth, milk from nipples, baby is born very immature Kangaroo, wombat, koala • Amphibians- early amphibians were big and goofy (these went extinct at the Paleozoic Mesozoic boundary)… modern amphibians are a monophyletic group • Reptiles • Turtles- the only anapsid reptile alive today Characteristics- no teeth, shell • Diapsids* (another type of reptiles) • Snakes- (type of diapsid) double jointed jaw bone allows them to open mouth very wide • “Lizards”- (type of diapsid) also have double jointed jaw bone…lizards are paraphyletic, gave rise to snakes · Archosaurs- three main groups are crocodilians, pterosaurs and dinosaurs • Plesiosaurs- type of amniote that returned to sea rather than being terrestrial • Ichthyosaurs-fish lizards, strictly marine, gave live birth in water • Mosasaurs- extinct group of fully marine lizards, lived during the Mesozoic Era • Crocodilians-live in freshwater and saltwater tropical oceans, close to land • Pterosaurs- winged lizards, first flying vertebrates to evolve NOVELTIES Who has them? What is their function (if any)? Those with an * have evolved independently in two or more groups. Make sure you know which. • Margin of bone at back of skull • Thickened skulls • Rostral bone • High nostrils • Frill • Horns • Long neck • Semi-opposable thumb • Thumb claw • Knife-like teeth • Hollow bones • Stiff tails • Highly stabilized tails with vertebral projections • Pubic ‘boot’

• Fused clavicles • Loss of teeth* • 1-2 hands • Semilunate carpus • Bowed ulna • Reverse pubis* • Big claw on digit #2 • Feathers • Powered flight • Double-hinged jaw • Placenta • Nipples • Milk production • Young carried in pouch • Aquatic habit * • Thecodonty* • Erect posture* PICTURES Make sure you know what the different major dinosaur groups look like. You may be asked to identify a particular dinosaur based on its image. (See list of possible taxa above and on midterm review sheet.) TERMS Be able to define these or (where relevant) identify in a drawing. • Body feather- has: prominent rachis (main shaft) Interlocked barbules (branches coming off barbs) These create a flat “vane” (aerodynamic surface) • Flight feather- is a body feather with asymmetric vanes • Downy feather- has: rudimentary rachis Jumbled tuft of barbs (branches), no flat vane Long, tangled barbules Lightweight, used for thermal insulation • Isotope- when the nucleus of an atom has the name number of protons but a different number of neutrons as another element Two types- stable (no radioactive decay, doesn’t change over time) and unstable (will undergo radioactive decay at some point) • Pangaea- two supercontinents = Gond (which is Antarctic and Australia and ect…) and Laurasia…these broke apart by the end of the late Jurassic • Gondwana- one piece Pangaea broke apart into • Panthalassa – large ocean of the late Triassic • Tethys- small sea of the Late Triassic • Triassic- Late Triassic is part 1 of age of dinos, 225-200 Ma • Jurassic- part 2 of age of dinos, 200-145 Ma • Cretaceous- part 3 of age of dinos, 145-65 Ma • K-T boundary-marks the end of the Mesozoic era and the beginning of the Cenozoic era • Iridium spike- very high levels are found deposited at the K-T boundary. Very rare on earth, and significant levels are only found in extraterrestrial rocks (meteorites and asteroids) • Shocked quartz- found at K-T boundary, only form in response to high pressures, likely formed by force of impact

• Microtektites- tiny tear-drop shaped pieces of rock, found at K-T boundary clays, have enriched elements that are rare on earth but common in meteorites • Chicxulub impact crater- found off the Yucutan Peninsula, Mexico dated 65 Ma • Transfer of function- preexisting novelty performing a different task than originally intented (ex: gill arches: support in breathing eventually became jaws) • Convergence- species from different ancestors evolving the same trait PEOPLE Why are they important? What did they do? William Smith-invented biostratigraphy (the use of fossils to tell time) Nicolaus Steno- one of the first people to realize fossils are the remains of once living creatures recognized the first three laws used to infer relative time (original horizontality, superposition, and lateral continuity) CONCEPTS: Make sure you understand these concepts. Where applicable, give examples. Surface area vs. volume- as organisms change in size, the surface area and volume change at different rates Small things have a large SA/V ratio, which means they loose heat more easily, while large things have a small SA/V ratio. Phylogenetic bracketing- bracketing species together in order to infer certain traits (used to guess things like color in dinos) Parsimony- simplest explanation is the best one (if you have four sister groups, and two of them are yellow, the simplest explanation is that their ancestor is also yellow, rather than evolving yellow independently) Ontogeny recapitulates phylogeny- when development replays evolution…the development of a structure mirrors the evolution of that same structure Relative dating- how old one rock is relative to another rock Five laws: 1. Original horizontality- originally rock layers were horizontal, now they are tilted 2. Superposition- younger rocks are laid on top of older rocks 3. Lateral Continuity- rock layers are continuous with each other, even if something (a river!) has cut through them 4. Cross cutting- a rock that cuts across another rock is younger than the rock is cuts across 5. The Law of Fossil succession- a unique succession of fossil species exists throughout time…species only live once, so once they die, they don’t come back. Absolute dating- how old the rock is in years Biostratigraphy-using fossils to tell time Biostratigraphic zonation- using fossills to subdivide time (gives us eons, eras, periods, and epochs) Biostratigraphic correlation- since any fossil can be placed uniquely in time, rocks that host the species must be the same age (or at least within the species lifetime) Stable vs. unstable isotopes- stable isotopes don’t change, while unstable isotopes undergo radioactive decay Biogeography- the study of how the position of land influences the distribution and evolution of life…land position affects evolution of life by the creation of geographic isolation through the separation of land masses Endemism-distinct faunas found nowhere else in the world (high endemism is a result of lots of geographic isolation, and low isolation causes low endemism) an example of this are the mammals found in Australia

Correlation vs. causation- correlation doesn’t equal causation Endothermy- ability to keep the body at constant temperature, requires a lot of energy, allows nocturnal behavior, may have caused: evolution of hair, milk production, infant-mother bonding Ectothermy –relies on heat from the outside enviornment Homeothermy- able to maintain a constant body temperature (usually endotherms, but ectothermic homeotherms-large creatures that maintain their heat b/c of their large size-exist) Pokilothermy- having a variable body temp over time (usually ectothermic, but endothermic pokilotherms exist such as bats, who are so small they have trouble maintaining a constant temperature) Metabolism- sum of chem reactions in the body; source of energy and heat Magnetic pole reversals Paleomagnetism Background vs. mass extinction- low level extinction rates are a normal thing (background extinction); mass extinction refers to the elimination of a huge percentage of Earth’s species Signor-Lipps effect- when sudden extinction appears to be gradual extinction Parent isotope vs. daughter isotope- the parent isotope decays into the daughter isotope MATH & OTHER PROBLEMS Surface area vs. volume calculations (example calculations in lecture 11) Radiometric dating and half-lives (example problem in lecture 17) Relative dating exercise (handed out in class; also posted online) Use of phylogenetic bracketing to infer where characters evolved in the tree (lecture 13) MISCELLANEOUS QUESTIONS TO HELP YOU STUDY • What’s the evidence for parental care in hadrosaurs? In Psittacosaurs? What about evidence that all dinosaurs exhibited parental care? Evidence for parental care in Hadrosaurs: nests, and skeletons of young hadrosaurs found together In Psittacosaurs: juveniles found clustered around one adult All dinosaurs probably cared for their young-closest living relative, crocs, care for their young, and so do birds, the only living descendant of dinos • What are examples of convergent evolution between ceratopsians and ornithopods? Both get dental batteries, larger size, and extensive head ornament. • Give two lines of evidence that Margin-heads were social animals. 1. Masses of skeletons found in bone beds (implies herd animals) 2. All of the head ornament, horns, and frills found on them (used for sexual competition, so there must be others to compete with) • Why did pachycephalosaurs have such thick skulls? Most likely for head-pushing (head butting is out of the question, there would be too much force), type of sexual competition • Why do scientists now think that sauropods did not hold their necks up vertically? If they held their heads up vertically, that means their heart would have to pump blood 4-5 stories to their heads, which would require a huge heart that scientists don’t think could biomechanically function. • What are the adaptations that sauropods evolved to deal with their really long necks? Cavernous vertebrae in the neck (makes the neck lightweight), tiny head, vshaped notch in vertebrae where cables of ligaments ran (cables used to hold neck

up), and perhaps a large heart • List two differences that help distinguish diplodocids, camarasaurs, and brachiosaurs. The nostril size and forelimb size get bigger with each group • Which of the following dinosaur clades includes the largest creatures ever to walk on Earth: theropods, ceratopsians, sauropods, stegosaurs, ankylosaurs? Sauropods • There are estimates that the dinosaur Amphicoelus may have been as much as 60 m long and 150 tons. Some scientists question this. Why? What evidence is this based on? • One idea for the large size of sauropods relates to their diet. What’s the explanation? The plants they ate were of low nutritional value, and the larger an animal is, the easier it can survive on lower quality foods • When did flowering plants first appear? • How does a change in size affect the generation and loss of body heat? What about the need for and acquisition of oxygen in insects? Why were insects able to get so big in the Carboniferous Period (mid Paleozoic Era)? Surface area is correlated with heat loss, and volume is correlated with heat generation. Holes in insects bodies allow oxygen to diffuse through them. The bigger an insect, the more need for oxygen, so the amount of oxygen in an atmosphere effects how big an insect can get. Insects were so big in the mid Paleozoic Era because oxygen levels were much higher at that time • How does a change in body size affect skeletal strength? The strength of a bone is proportional to an area, and body weight scales with volume. So weight increases faster than bone strength. In order to deal with this, bones become thicker rather than longer. • Why do scientists no longer think that sauropods lived in swampy environments, using their long neck as ‘snorkels’? Their necks are too long (they’d have too much pressure on their lungs, which would be 10 m below the waters surface) and their limb bones are clearly sturdy enough to support their weight on land. • What were sauropods like? Migratory? Herding behavior? Did they take care of their children? Sauropods may have moved in herds, and would have been migratory because of the amount of food they would eat. There is evidence that Sauropods were friendly towards each other and took care of their children. • True or false: Sauropod diversification coincided with the diversification of flowering plants. • What were early theropods like? Sweet and cuddly? Slow-moving and vegetarian? Efficient hunting and killing machines? Early theropods were terrifying meat eating killing machines. • What might have been the original function of feathers in the earliest feathered dinosaurs (list two possibilities)? Did feathers evolve for flight? Explain your answer. The earliest function of feathers in dinos may have been for display or for insulation, but they did not evolve for the purpose of flight. • Birds are an amalgam of different characters that evolved at different times in their ancestry. Here’s a list of some modern bird characters; indicate the order in which they appeared in the ancestry of birds: o Hollow bones o Fused clavicles (wishbone)

o Erect posture o Digitigrade stance o Feathers o Loss of tail o Loss of teeth o Powered flight o Antorbital fenestrae o Carpometacarpus • Why can’t we use carbon-14 dating on rocks older than about 70,000 years? Its half-life is too short • Why can’t we use uranium-lead dating on really young rocks? Its half-life is too long • Discuss four trends in synapsid evolution. (1) Improved food processing- synapsid hole increases in size, improved ability to chew food, loss of lower jaw bones (single jaw bone allows better control of the lower jaw), changes in teeth (thecodonty-embedded teeth), and secondary roof of mouth (palate- separates passages for air and food) (2) Changes in hearing- two new ear bones (malleus and incus) (3) changes in locomotion- erect posture (4) Changes in physiology- improved, double pump heart • There were two diapsid diversifications, one in the Mesozoic and one in the Cenozoic. Which diapsid groups diversified in each Era? • How do pterosaur wings differ from bird and bat wings? Are wings in these groups homologous or convergent? Pterosaur wings differ in their structure from bird and bat wings, implying that they evolved convergently. • Mammals have three ear bones. What are they and where did they come from? Stapes (stirrup), malleus and incus (hammer and anvil). All derived from jaw bones lost in synapsid evolution. Evidence for this found in the development of ear bones in mammalian embryos. • When did the following groups appear ?(Permian? Middle Triassic? Late Triassic? Jurassic? Cretaceous? Tertiary?) o Turtles-late Triassic to today. Greatest diversity occurs in late Cretaceous o Mammals-late Triassic o Pterosaurs-late Triassic o Dinosaurs-late Triassic • Give two examples of how preservational differences can influence the pattern of dinosaurs in time and space. (1) Rock volume varies through time and (2) different dinosaurs have different ‘preservabilities’ (hollow bones are hard not well preserved) • Give two examples of “collection bias”. (1) Inaccessibility (could be due to ice sheets, Antarctica, or political instability) and (2) finds are based on the nationalities of the paleontologists. • What is the relationship between endemism and geographic isolation? Geographic isolation causes endemism, which is fauna being specific to only one part of the world • What is the relationship between endemism and global diversity? High endemism means higher global diversity. Each isolated area has different species, which add to the overall diversity of all species. • What was climate like in the Mesozoic (e.g. vs. today)? How did climate change through the Mesozoic? What about geography? Biogeography? Vegetation? Vertebrate biota (incl. marine life)? Which dinosaurs lived during the Triassic? Jurassic? Cretaceous? i. Late Triassic

Geography: Pangaea = Two supercontinents = Gond (= Antarctic + Australia + etc.) + Laurasia One large ocean = Panthalassa One small sea: Tethys Few mountain ranges or volcanoes Biogeography: Low Endemism: species had wide ranges Climate: No evidence for polar ice caps, no glaciers or snowy winters Warm, less of a temperature gradient than we have today Strong Monsoonal seasonality: alternating hemisphere wide: wet + dry seasons Vegetation- No flowering Plants (aka Angiosperms; this means no grass, no flowers, no fruit, no palm trees…) Ferns in understory Seed plants: cycads, conifers, ginkgoes (still around today but minor compared to flowering plants) Vertebrates: Oceans: Sharks + bony fish, plesiosaurs + ichthyosaurs diverse Land: “Early Synapsids” in decline, “Early Archosaurs”: Postosuchus, phytosaurs, aetosaurs (extinct by late Tr) Turtles, Pterosaurs, mammals – early representatives: all appeared at same time as dinosaurs. Dinos that lived in the Triassic-mostly small (herrerasaurus, lesothosaurs; Prosauropods and Ceratosaurs were the largest at only 8m) ii. Jurassic (200-145) Geography: Pangaea breaking apart – by end Jurassic: split into Laurasia and Gondwana Biogeography: increased endemism Climate: warm, monsoonal, Drier: vast areas in w. Nam: as big as Sahara By the end of the Jurassic: a bit wetter Vegetation: Cycads, conifers, ginkgos, Ferns not so dominant because Jurassic was drier. Like amphibians, ferns depend on water to reproduce. Other vertebrates: Big extinction at end of Triassic-most large amphibians extinct; early synapsids extinct, lost early Archosaur lineages. Largest Plesiosaurs (e.g. 50 ft Plesiosaur), ichthyosaurs Other vertebrate lineages were mostly small: mammals, pterosaurs, turtles. Big crocodilians, though! Dinos that lived in the Jurassic-beginning of dino domination in the early-mid Jurassic (Ceratosaurs (theropods), small sauropods and small stegosaurids), and then the Golden Age of Dinos in the late Jurassic (huge sauropods, large stegosaurs, smallmedium ornithopods, carnosaurs, and the first birds (Archaeopteryx)) iii. Cretaceous (145-65 Ma) Geography: Gondwana breaking apart; Laurasia breaking apart New Ocean: Atlantic Biogeography-Lots of endemism (Distinctive dinosaur faunas in different regions) Climate-Greenhouse: warm & wet Dinos living at poles: e.g. Antarctica, Australia were below the Antarctic circle ‘winter night’: sun sets, and won’t rise again for up to a few months Although relatively warm (no ice caps), still cold. Vegetation: Flowering plants appear in early Cretaceous; diversify at end of Cretaceous Other vertebrates: Mammals diverging into modern groups: placentals, marsupials, monotremes Birds appeared by now, + diverging Mosasaurs top of seafood chain Birds becoming relatively diverse

Dinos that lived in the Cretaceous-highest diversity, smaller dinos though (larger ornithopods, Ceratopsians, Pachycephalosaurs, smaller sauropods, ankylosaurs take over for stegosaurs, T. rex and other coelurosaurs) • Why were the continents partly flooded during the Cretaceous? Give two reasons. B/c there were no glaciers, and there were lots of mid ocean ridges displacing water • Why can’t we use phylogenetic bracketing with living animals to determine whether non-avian dinosaurs were endothermic? Dinos are bracketed by birds (endotherms) and crocodiles (ectotherms). • What’s the relationship between endothermy and metabolism? Endotherms require a fast metabolism (source of heat); this high metabolism means endotherms must eat much more food; higher metabolism also translates into greater stamina for endotherms • What’s the “predator/prey ratio argument” in favor of endothermy in theropod dinosaurs? What’s one problem with this argument? There is a mass ratio of dino predators to dino prey (b/w 1:100 and 1:33), which is in agreement with the prediction of predatory dinos being endotherms. One problem with this is it assumes that all the prey is eaten by a predator, when in fact many prey dinos die from other causes. • What’s the ‘insulation’ argument for endothermy in at least some dinosaurs (which ones?)? Endotherms have some type of insulation, and some dinosaurs evolved feathers (Coelurosaurs) which could have been used for insulation. • What’s the ‘Pterosaur’ argument for endothermy in dinosaurs? Since Pterosaurs and birds were endotherms, using phylogenetic bracketing dinos must be too. (Problem: phylogenetic bracketing is useful, but not always correct) • Why does the geographic distribution of dinosaurs suggest they might have been endothermic? What’s potentially wrong with this argument? Dinos are found in regions that were once at polar latitudes (endotherms can keep themselves warm in cold weather). Problem: Cold regions were decently warmer during the Mesozoic, and the dinos could have migrated there in the summer months rather than lived there year round • Why do we think the largest dinosaurs (e.g. sauropods) were not endotherms? Large body masses would require a lot of cooling off, which would not be helped at all by having a high metabolism which produces tons of heat. • List some of the hypothesized effects of a giant meteorite impact (e.g. global wildfires). Blast wave, tsunamis, earthquakes, global wildfires, massive increase in temperature (for about 30 days), massive amount of dust sent into the atmosphere blocking out the sun. • List three lines of evidence suggesting that an extraterrestrial impact occurred at the end of the Cretaceous. (1) Asteroids and meteorites have impacted Earth in the past (we have craters from these) (2) There is an Iridium spike in the clays right at the K-T boundary (Ir is very rare on earth, but not in asteroids) (3) There are fractures in quartz, which can only be caused by high pressures, found in K-T boundary clays (4) Microtektites, or tiny round pieces of rock, containing elements rare on earth were found in K-T boundary clays (5) Huge crater, Chicxulub Crater, is exactly the same age of the K-T boundary and an impact big enough to cause such a crater would produce more energy than 100 times all the world’s nukes.