Earth Sciences 2266F/G Lecture Notes - Lecture 16: Skull, Zygomatic Arch, Occipital Condyle

• School: Western University
• Department: Earth Sciences
• Course: Earth Sciences 2266F/G
• Professor: Jisuo Jin

Document Summary

Secondary bony palate: upper palate from soft palate to bony pieces. Coronoid process: hockey stick-like structure in lower jaw; gets bigger. Orbit: normally is one opening (in all synapsids, just that one temporal fenestra); during this development the orbit and the temporal fenestra become fused into a single opening on the side of the skull. E. g. pigs have eye socket and temporal fenestra is a single opening. In humans, there"s a bridge between the 2 holes (change back to the earlier state!) Development of mammalian jaw joint; in the early forms of therapsids, their jaw joint is still reptile-like, and mammalian jaw joint is much more forward in its position and much more leverage for biting. Humans have high cheekbone: related to lateral bulging of this ridge; zygomatic arch is on top of ear, coronoid process goes into this and jaw muscles goes into this area to manipulate our lower jaw can eat better.