BIOC50H3 Lecture 9: Lecture Nine
22 Dec 2018
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Document Summary
Tetrapods part 2: marine monsters of the triassic, jurassic and cretaceous. We"re talking about pterosaurs, dinosaurs and relatives. In phylogeny tree, this is archeosauromorpha: it"s a diapsid, closely related to squamates and tuatara. It might have been the intermediate stage leading to pterosaurs. It has a membrane between its hind limbs and tail and possible also to its forelimbs. From neck region to one of the digits: 2. Dinosauria is one group of the dinosauromorpha: includes dinosaurs, tiny dinosaurs were less than 3 m. Oldest dinosaurs: evolved in the mid to late triassic; fairy small at this, oldest discovered dinosaur is 231, end of the triassic extinction event caused their demise allowing dinosaurs to take over as dominant in jurassic. Defense, flank butting or for display: have strong skeletal feature at the top of the head, still bipedal, ceratopsians: triceratops and yinlong, yinlong represents a transitional fossil leading to latter. Evolved from small bipedal ancestors that walked up upright.
