British anatomist Richard Owen took stock of all of the crazy fossil giants being found in Europe and noted they were different than reptiles living today in being Giant Having upright posture not sprawling like living reptiles Having more than two fused sacral vertebrae KNOW When did dinosaurs live 238 million years until 65 5 million years ago during what is called the Mesozoic Era or the Age of Dinosaurs KNOW Who lived with the Dinosaurs Keep in mind that all dinosaurs appear to have been terrestrial We have no credible evidence they were either amphibious or aquatic Something must have been in the air and water KNOW Crocodilians and their close relatives First ones were terrestrial land dwellers Some were even bipedal Some were fully aquatic sea monsters Deinosuchus growth Grew at rates like living alligators very unlike the dinosaur pattern Supercroc Sarcosuchus Saltwater crocodile 3 700 lbs highest bite force ever measured KNOW Supercroc and Deinosuchus 31 000 lbs of force It is important to realize there is another category of fossils called Trace Fossils KNOW Where do we find dinosaurs Most commonly in Sedimentary Rocks These are composed of consolidated sediments from rivers or desert windstorms where a dead animal was buried quickly Know The plated lizards or Stegosaurs were characterized by Plates and spikes along or beside the backbone KNOW Why the crazy theories Paleontology has history founded solely in geology biological training in anatomy physiology and animal behavior have been part of the curriculum KNOW We do not know the sex of dinosaurs KNOW But in the case of dinosaurs like Heterodontosaurus we have evidence of sexual dimorphism one sex bigger than the other Sexual dimorphism KNOW The tooth batteries are interesting in that they were self sharpening The hard enamel was on one side of each tooth and created a wedge like wear pattern that kept the teeth continually sharp The teeth were replaced one after another throughout life as in most reptiles KNOW It has been shown that many of the hadrosaurs hastily named by Cope Marsh and others were actually juveniles in which the crests had not developed Oversplitting KNOW There has been a lot of debate as to what the domes were form competing theories include Structures for head on butting reminiscent of big horn sheep pugs and musk oxen KNOW Structures for flank butting like many mammals do today the knobs are driven into the sides of rivals in competition KNOW Skulls have been sectioned and computerized renditions called Finite Element Models made dissipations of force can be assessed KNOW The earliest ones were small hornless and were called Protoceraptosians KNOW Protoceratops from Asia is the most famous protoceratopsid This animal lived in a desert environment and has been found buried in prehistoric sand dunes Their skulls show Sexual dimorphism KNOW Some think the pachyrhinosuar boss was for shoving matches others think it was the base for the large horn ever KNOW During Cope and Marsh s race to name dinosaurs Triceratops was oversplit into no less than 16 species The confusion came from the naming of young scarps males vs female and variation between individuals oversplitting KNOW Could you fit a Supersaurus in Ruby Diamond NO KNOW Sauroposeidon 56 feet KNOW The nostrils on the top of their heads were viewed as snorkels some even thought there was a trunk much like that of living tapirs KNOW The skull of Allosaurus is remarkably lightly built Recently Emily Rayfield from Cambridge University made computerized biomechanical finite element model of the skull to determine how strong it was and the bite forces it could endure KNOW Their leaf shaped teeth suggest they were the only herbivorous theropod dinosaurs KNOW Segnosaurus What were they doing Another weird group of coelurosaurs were the crested toothless Oviraptors Which way is forward for the skull KNOW Largest relative brain size of any dinosaur Encephalization Quotient KNOW EQ nearly equal to that of modern birds and size times greater than living alligators Dinosauroid may have been the outcome KNOW Deinonychus was 7 11 feet long this was the real raptor in Jurassic park Also the animal that fueled the dinosaur renaissance KNOW The tail of the tyrant Not having the end of the tail Osborn decided to make it 45 feet long and put a cute curly tail on the mount KNOW 2 claws and tail not dragging Brochu s CT scans of an entire T rex skull have been shown these animals had huge olfactory bulbs great sense of smell KNOW Endocast KNOW Roland also reported the first cases of cannibalistic behavior amongst these animals and confirmed speculation that bite marks are considerably more common on isolated elements versus who skeletons KNOW Tyrannosaurs were gregarious T rex both predator and scavenger KNOW The 1960s signaled in the dinosaur renaissance Deinonychus and Robert Bakker stimulated a reanalysis of our perception of dinosaurs KNOW How were growth rates determined Using histology which shows a blend of fast growing bones like mammals but growth lines when it stopped each year like reptiles growth line counts revealed ages size estimates allowed rates of growth to be calculated throughout development KNOW Maximal growth rates we calculated for the tiniest and largest dinosaurs and compared to living animals The results All dinosaurs grew considerably faster than living reptiles KNOW In fact they gew like Marsupial mammals KNOW What we think of as dinosaurs disappeared 65 5 million years ago during one several major extinctions that have occurred in Earth s history Not just dinosaurs perished 40 80 of all life on the planed died KNOW the pterosaurs mosasaurs plesiosaurs many clams plankton corals a few mammals and some plants all bit the dust fed the tree started pushing up daisies Survivors included most birds mammals amphibians and reptiles The three most plausible theories includes KNOW Theory Volcanism in India altered the earth s climate Evidence Deccan Basalts in India Theory Drastic lowering in sea levels ecological changes that affected the dinosaurs Evidence Seaway sediments Theory A 10 km wide asteroid hit the Gulf of Mexico and sent debris high into the air caused major climatic change Evidence The rare material iridium is found in ash layers known marking the KT boundary Shocked quartz modified minerals from explosions like nuclear tests are also found A purported impact crater is found in the Gulf of Mexico and tidal wave deposits are found
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