Earth Sciences 2266F/G Lecture Notes - Lecture 15: Draco Volans, Diapsid, Protorosaurus
26 Jul 2016
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Document Summary
We"ve talked about the anapsida; turtles (testudines) will eventually survive; they"re related to anapsids. Diapsids eventually led to modern reptiles, and another group evolved into archosauria: crocodiles, dinosaurs, and eventually birds. Diapsids are easy to identify: on the back side there are 2 holes (fenestrae) and other side are another 2 so total 4 holes. Hole is in between parietal and squamosal and postorbital bones. From this group on, they always have these 2 holes including dinosaurs. Diapsids evolution: in their early evolution, they are geared towards agility light body, light- boned for fast movement; thus their bodies are very agile including dinosaurs, and that"s why birds can fly since they"re so light-bodied. In their adaptation onto land, they started off as insectivores; chasing insects require very quick movement. Light-weight skull: huge eye for judging distance and positioning, and holes at the back make their skull very light (not much weight in skull)
