Earth Sciences 2266F/G Lecture Notes - Lecture 17: Antorbital Fenestra, Trigeminal Nerve, Diapsid
26 Jul 2016
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Document Summary
Most of the reptiles during this age were mostly archosaurs. All flying verts except bats are in archosaurs. Hallmark characters are synapomorphic characters: shared within all archosaurs. Antorbital fenestra: (orbital = eye socket) antorbital hole is in front of the eye socket. Mandibular (aka lower jaw) fenestra: hole in lower jaw. Teeth: most lizards are laterally compressed; even the sides are sharp, so really good at slicing for efficient predation. Diapsids: light body, agile, some can even glide. Within diapsids, they evolved into another clade called the archosaurs. Lepidosauria: giant marine reptiles (ichthyosaurs, modern lizards, snakes, etc. When you think of the fully developed groups (crown groups) within the archosaurs: crocodiles, pterosaurs, dinosaurs, and birds. Thecodonts is a paraphyletic group, including the early branches. Archosaurs are not truly successful in water, only crocodiles, but they rely on shallow water since they"re not good swimmers. 2 modes of life for archosaurs: land and air; not aquatic.
