Exam 3 Questions Flashcards

Question

When did Prosauropods evolve/disappear from the fossil record? Describe the key features that they all share.

Answer 1

Primitive form of sauropods Long neck, small head long tail, barrel shaped distinctive mobile thumb and powerful claw primitive leaf shaped teeth gastroliths herbiv EJur/late Tr- EJur

Answer 2

skull nares migrate over time from tip to up not chewing LArge, returned to nesting grounds shallow trops, 15cm eggs, 15-34 per nest, abandoned, grew 12000 pounds a year, sexually mature at 20

Answer 3

eJ- lK Largest animals long necks, small heads, not intelligent non occluding teeth in front of mouth obligate quadrapeds teeth changed form leaf shaped-> spoon shaped limbs-> rigid columns sexually dimorphic plantigrade and digitgrade tail did not drag air sacs

Answer 4

Prosauropods (TR- LJr) -Primitive forms, long necks, small heads, barrel-shaped bodies, long tails * Front limbs < hind limbs, suggesting primitive bipedality * Distinctive, mobile thumb with powerful claw * Primitive “leaf-shaped” teeth * Gastroliths, indicating food processing in the stomach * Probably herbivorous Eusoropoda - More primitive characteristics * Still large and quadrapedal * All sauropods descended from this basal group Diplodocoidea Extremely elongate, even gracile sauropods * A single narial opening at the top of the skull * Rows of thin, chisel-like teeth like a comb; restricted to the front of the jaws * Forelimbs shorter than hindlimbs * Whip-like tail, living in herds, and big size gave protection Neosauropoda Macronaria Have a large, retracted narial opening on a robust, stout skull * Long forelimbs and shorter tail compared to the Diplodocids * Stoutly built Camarasaramorpha Ate tough plant material – more spatulate (less thin) teeth than diplodocids * Distinctive cranial profile with a blunt snout and an arched skill that is square * 'Chambered lizard' referring to hollow chambers (plaurocoels) on its vertebrate * Only moderate length neck by sauropod standards Titanosauria Largest (heaviest and longest) animal (marine or land) of all time – 60 metric tons! * Survived until the K-Pg extinction

Answer 5

Bird-like pelivs eJr- K Predenstary bone, unpaired extension of lower jaw developed large stomach and intestional region chewed food, cheeks may have been primitive feathered skuyll 3 sections - beak: rhamoptotheca (inscisors) - diastema (middle part, gap, toothless) - Cheek teeth: back of skull grind down food expansion of coronoid process

Answer 6

Late triassic Pisanosaurus from the late Triassic,

Answer 7

Dermal armor or body plates on the back of the body. All share: dorsal rows of dermal armor Earliest in Early Jurrassic

Answer 8

9m 2000kg - browser - northern hemisphere - quadraped - solitary - front< back legs - dramatically sloping profiles - not smart - liesure - spiked tails - plates could have been for cooling or display, used to think defense - weak jaws but chewing teeth Late Jr

Answer 9

Ankylosauridae and Nodosauridae - wide bodies - gut fermentation - grinding teeth - large throat bones and strong tongues - low brosers - armored skulls - inset teeth - 5m Ankylo: - tail club triangle head squamosal horns prominent heavy build head down Mid Jr Nodosaurids late jr no tali club should spikes elongate head long snout powerful shoulder muscles more gracile head not angled down - slow, solitary,

Answer 10

Pachycephalosauria: Ceratopsia: Late Jr- Late K all bear a ridge or shelfe of bone on back of skull many shapes and sizes N hemisphere during K

Answer 11

Late K - teeth and abdominal regions large bipedal ornithscians with thickened skull roofs peg like teeth small thamphotheca - typical brain - enlarge smell - back half angled downward brain - thickened skulls for rams, secual display, or something else? 3, 45kg omnivorous? NA social behavior

Answer 12

LJr- K N hemisphere Quadrupeds thick hooves 6-7 metric ton tanks hooked beak skulls rostral bone horns frill herd chewer not girthy fairly quick and intelligent Psittacosaurus eK - 2m 50kg beak round skull unique rostral bone, flared cheek bones melasomes 2 or 4 Triceratops late K 9m 5500kg horny beak, dental battery smark parental care horns

Answer 13

Iguanodon, Hadrosaurids (duck-bills) Middle Jr- end K - Cows of mesozoic - all herbivores - numerous, diverse, everywhere - early 1-2m later 15m - long tail, muscular, strengthened by ossified tendons - horizontal - powerful hindlimbs - fairly quick when springting Gracile forelimbs - herbivores - beak, diastema, cheek teeth, inset row, bacterial fermentation - smart sexual display for skull arched snouts, low broad bump on head, traveled in herds some htachlings were instant travelers, some weren't. parential care shown.

Answer 14

Orodromeus - 2m -50kg - horny beak - grinding cheek teeth - small, bipedal, Na, burrowing Camptosaurus - Late Jr - 5m 1000kh - beak and teeth - heavy - no thumb spike - 2 or 4 legs Hadrosaurids - Late K - 9m, 3400kg, large bipedal - bipedal - duck billed - cropped vegetation with beak - large - crest on head -reduced 1st and 5th digit hands Iguanodontidae - Early K - 10m - 4000kg - chewing teeth and horny beak - long tongue - four limbs or two - thumb spike (1st digit) - 5th digit opposable pinky

Answer 15

Ground up, Tree down.

Answer 16

Enlarged Scapula, furcula, keeled sternum, pygostyle, pelvis similar to ornithischian but is saurischians, clavicle, femur, sternum.

Answer 17

Herrasaurus Prosauropod lTr 3m, 350kg, flexible joint in jaw for sliding to bite, serrated teeth carniborous but preyed on one earliest fossilized strong bipedal, long feet, short thighs, swift runner basal- traits from arch Eorapotor L Tr Prosaur 1.7m, 10kg, small razor teeth, omnivore Small, lightly built, basal, biped, fast, five digits on hands, humid, warm Plateosaurus L Tr 7m 4,000 Kg, grinding Teeth, horny beak 2 or 4 legs 5 fingers, large thumb herds