Earth Sciences 2266F/G Lecture Notes - Lecture 18: Antorbital Fenestra, Sacrum, Femoral Head
26 Jul 2016
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Document Summary
One of the oldest dinosaurs from argentina (where most of the early dinosaurs were from) Their feet"s palm stood up and became part of the leg. By this stage, you can identify all the archosaur characters: antorbital fenestra, lateromandibular fenestra, etc. which are also shared with crocodiles and birds (early birds had teeth) Open acetabulum in the middle (open space) as the hip joint, where femur touches hip open acetabulum hole is for femur head to insert into hip (in us, there"s just a depression, no hole), so better running. Upright posture gait took a while to develop. First, sprawling gait, then semi-erect gait (jut out, then go vertical), then erect gait (totally vertical and start to bend underneath the body, unique to dinosaurs) Crocodiles diverged earlier from dinosaurs so they never developed the erect gait body posture. Dorsal vertebrae means from junction of hip to junction of shoulder girdle. Vertebrae fused to ilium of pelvis is the sacral vertebrae.
