Test Review Dinosaur Unit BSC 1005 The cladogram Page 129 in the book will be provided for the test Learn how to use this as it contains answers to about 40 of the test questions according to Dr Erickson A paleontologist is someone who studies any aspect of ancient organisms This course is about paleobiology the study of the lives of ancient organisms the animals physiology behavior ecology functional anatomy The first written dinosaur accounts are from China The first dinosaur bone was found in England people originally thought it was the scrotum of a dead giant human It was actually the end of a theropod dinosaur s thigh bone The bone was incorrectly named as Scrotum humanum In 1770 a forty foot sea monster named Mosasaurus was found in Holland Cuvier said it was remains of something that no longer lived This was the first time the idea of extinction was postulated Buckland found Megalosaurus the first validly named dinosaur No one cared about this find because of reports of giant lizards and crocodiles in Africa still alive at the time made the huge bones seem comparable to those of living organisms Igunadon iguana tooth The first herbivorous dinosaur Be able to identify the tooth based upon the picture in the textbook on page 6 Richard Owen be able to recognize his picture page 7 in the textbook took stock of all the crazy fossil giants being found in Europe and noted the bones were from animals different from reptiles He named this new category dinosaurs in 1842 the name means fearfully great reptiles Dinosaurs had teeth in sockets like crocodiles and pterosaurs flying reptiles and are their close relatives BUT crocodiles did not evolve from dinosaurs as they existed at the same time back in the Mesozoic Era Pterosaurs had upright postures Unique dinosaur features o Three or more sacral vertebrae o Three main fingers o Perforate acetabulae By the late 1800s there was enough evidence to realize that there are two types of dinosaurs o Ornithischians with pelvis bones hips shaped like those of birds o Saurischians with pelvis bones hips shaped like those of lizards Dinosaur Renaissance fueled by the discovery of Deinonychus which was found by John Ostrom in 1964 The dinosaur made us realize that dinosaurs were more like birds than mammals and made them very interesting and appealing to study Robert Bakker took this idea that dinosaurs were more like birds than mammals and ran with it Dinosaurs lived from 238 million years ago until about 65 5 million years ago How do we know these ages o Uranium lead dating Uranium 235 decaying to Lead 207 half life Climate in dinosaur times o A lot warmer desert like or arid like in Florida o No ice at the poles o It was much like the Florida Keys of today all across North America because there was no ice at the poles there was a lot more water covering everything This water limited dinosaurs mobility as there were places they could not access since they couldn t swim Continents have moved since the times of the dinosaurs the idea of continents moving is called plate tectonics Who lived with dinosaurs o Crocodiles some like those of today some terrestrial some marine creatures Deinosuchsus a gigantic 32 foot crocodile that lived at the time of dinosaurs Sarcosuchus 18 000 pound bite force Compared to the saltwater crocodile of 3 700 pounds the highest bite force ever measured in a living animal These bite forces were measure at FSU o What people call the Loch Ness monster was really just an animal called a Plesiosaur It was long necked like a large lizard It was not a monster or a dinosaur o Mammals appeared at the same time as dinosaurs but were all really small like possums and chickens So mammals did exist with dinosaurs The best way to figure out information about dinosaurs is through trace fossils Trace fossils are not bones but evidence like dinosaur eggs tracks skin impressions gastroliths stones that dinosaurs swallowed to aid digestion coprolites dinosaur feces o From these we know that most dinosaurs did not drag their tails The tails were held up the air behind them o Trace fossils are usually found in volcanic rocks o Where do we find these fossils and regular dinosaur fossils do we just start digging No They are found in places where dinosaurs lived in Mesozoic Age sediments usually in the Badlands areas The closest place you can find dinosaurs around here is in Georgia No dinosaurs have been found in Florida there were some that lived here but all the sediments have washed away Specific Dinosaur Information by Type o Ornithischians can be identified by bird shaped hip bones and beaks to crop plants The first ones appeared in the Middle Triassic Period 225 million years ago Like all early dinosaurs the first ones were small A major group of ornithischians were the Thyreophora shield bearers a k a armored dinosaurs o They had osteoderms like those on the backs of alligators These were bones in the skin on their backs o Major group of Thyreophoran dinosaurs stegosaurs Stegosaurus a specific stegosaur was the supermodel for stupidity i e one of the most stupid dinosaurs we know this from endocasts sediments that filled the brain cavities of dinosaurs or from filling hollow skulls with latex and looking at the resulting impressions to see how big the brain cavities were Another group of ornithischians were the Cerapodan dinosaurs Their distinguishing feature was the existence of a gap between their front and back teeth o There are two subgroups to the Cerapoda the Ornithopods and the Marginocephalia Ornithopods one main group Heterodontosaurs were one of the earliest types of ornithopods All of their teeth had different shapes like those of mammals Reptile teeth are usually all the same size Be able to identify them from the picture in the textbook on page 42 o What was the deal with fangs on plant eating animals like the Heterodontosaurs This is not uncommon the structures are used for sexual display Hadrosaurs are a type of extremely advanced ornithopods Their characteristic feature was their duck like bill They had dental batteries hundreds of interlocking teeth one after the other If they lost one tooth they could just spit it out and keep going o These dental batteries were self sharpening The hard enamel was on one side of each tooth and created a wedge Be able to identify them from the picture on page 46 in the textbook o We know more about Hadrosaurs than we do about other dinosaurs why For many reasons we have found
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