Dinosaur Exam 4 Bio Review TA Review o someone who studies ancient organisms Paleontologist Paleobiology o Cladistics Fossils remains of ancient life o For dinos we tend to think solely of these as bones o A method to organize physical characteristics of dinos and disce rn relationships Encephalization quotient o a measure of brain size relative to body mass Where were first written dinosaur accounts o China England Scrotum humanum story o First proper scientific named dino was S H so named b c thought to be dino private parts now known to have been the end of a dinos thigh bone Gastroliths gizzard stones and in digestion like our molars as well as stomach contents Mosasaurus o Reveal capacities to further breakdown foods and what was eaten o Sea monster o Cuvier things go extinct o Concept of Extinction was for the first time realized by a few o Aquatic animals closely related to todays monitor lizards like the Europeans komodo dragon Megalosaurus Iguanodon o iguana tooth Richard Owen o Took stock of all the crazy giants being found in Europe and noted they were diff than the reptiles living today o Picture o Giant have upright posture o Named them dinosauria meaning fearfully giant reptiles Dinosaurs related to o Who is closer related Pterosaurs or lagu Pterosaurs Lagu Pterosaurs in the air first ones had long tails some were filter feeders some had been found with fur Mammals appear at the same time as dinos o Mostly rat or possum sized throughout the age of dinos In the late Jurassic birds show up o Bird hip dinos These constitute about half of all dinos and is a group composed solely of herbivores p 129 Ornithischia Bird shaped hip bones Beaks to crop plants The first ones to appear in the middle Triassic period 225 mill Like all early dinos they were small 30 100 lbs and were years ago bipedal DINOS START SMALL AND END BIG test Q They had simple leaf shaped teeth that didn t occlude and thus presumably ate succulent tplants like many lizards today with similar dentitions A major group of ornithischians were the thyreophora shield bearers or armored dinos The diagnostic characteristic was armor or osteoderms like those on the back s of alligators Stegosaurs supermodel for stupidity o Later forms of thyreophora o Characterized by plates and spikes along or beside the backbone o Two ton stegosaurs had 2 5 2 9 oz brains WOAH Ours are 3 3 5 pounds o Their olfactory bulbs were relatively large suggesting a good sense of smell 3 key features of dinosaurs dinos have teeth in sockets like crocodiles and pterosaurs and are thus close relatives o three or more sacral vertebrae fused backbones in hip regions o hands with 3 main fingers o perforate acetabulae i e the hole where the thighbone attached goes all the way through the hip dino renaissance o ostrom discovered deinonychus an athletic animal o Robert bakker said that all dinos were athletic and more like living birds and mammals o Outcome everyone started studying dinos and jobs were created more money is spent on dinos than ever before o By the late 1800s there were 2 types of dinos Hips shaped like birds ornithischian Thyreophora Hips shaped like lizards saursichians When did dinos live how do we know o 238 million years ago until 65 5 million years ago o Uranium lead dating o Look at Radioactive isotopes in volcanic rocks Compare original amount to final amt to assess age o For dino age uranium 235 is best It is pure when volcano rocks look cool carbon dating is too short to be of our use for dinos World was warmer back then ecosystems shifted north Life of dinos on earth o By middle of cretaceous period flowering plants started showing up These plants regenerate quickly can survive grazing o Who lived with the dinos Keep in mind that dinos were terrestrial We have no credible evidence that they were amphibious or aquatic o Continents moved 32 foot deinosuchus was a CROCODILE o Picture Largest bite force of crocodile supercroc 3700 pounds o American alligator 3000 lbs o Saltwater croc 3700 lbs highest bite force ever measured o Supercroc 31 000 bs Turtles o Were like todays turtles but some reached giant sizes Plesiosaurs NOT a dino o The supposed loch ness monster sea monster We know their fin profiles and we know they gave live birth o Traces of creatures they aren t physical remains of the animals Trace fossil tissues Includes dino tracks eggs bite marks coprolites skin impressions etc Bite marks tell us who ate who Skin impressions reveal aspects of thermoregulation and display features Eggs and nests aspects of ovaries Coprolites tell us what they ate if they had strong digestive acids how much the dentition broke down items o No actual tissue Tracks dinos didn t drag tails o Reveal aspects of posture walking and running speeds group behavior b c of tracks we know dinos didn t drag their tails Find dinos o in sedimentary rocks rivers deserts etc very rarely find them in volcano rocks or metamorphic rocks o Best place to find Badlands o Closest place to find dinos Columbus Georgia Wont find dinos in FL lolz Endocasts formed by sediments filled brain cavities during fossilization process and became solidified o See how smart dinos are know brain size of dinos f this Oversplitting naming more species than there really are Paleontology has history found solely in geology Cerapodas o Ornithischian group o The distinguishing feature of the cerapodans is a gap b t the front and back teeth called a diastema o Ornithopods We know more about their biology than any other dinos b c they were often gregarious herding animals Sometimes we find them in the thousands o Heterodinosaurs were one of the earliest types of ornithopods They were small herbivores t he teeth of these dinos were mammal like o Unfortunately we don t know the gender of any dinos o But in the case of heterodontosaurus we have evidence of sexual dipmorphism one sex bigger than the other o have gap in teeth Triceratops o the largest and most famous ceratopsian o three horned faced dino o often seen facing off with T rex o triceratops were split into no less than 16 species the confusion came from confusion from naming of young male v female OVERSPLITTING o likely triceratops used horns for defense at times but one must keep in mind that horns in most animals today are used primarily for display and fighting one another o frills have posited as thermoregulatory devices defensive structures and display devices Heterodontosaurs diff shaped teeth o Picture Sexual
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