GEOL 1066 : Dinology Exam 2
Document Summary
Reptile skull openings--facilitate jaw muscle action anapsid-- cotylosaurs and turtles parapsida--upper opening- ichthyosaurs euryapsida--upper--plesiosaurs synapsid(lower) --pelycosaurs, therapsids and their descendants thecodonts(a grade) and therapsids diverge in permian. Archosaurs (dinosauria and pterosauria--both have erect posture with legs under body) In britain, owen, buckland, & mantell studied specimens prior to the naming of "dinosauria" Mantell worked on the first herbivorous dinosaur to be studied, iguanodon. Classic differentiation has been on pelvis form, and this still works if you are looking at a mounted skeleton. In ornithischia at least part of the pubis runs back along the lower edge of the ischium. Ornithischia usually have a predentary bone at the front of the lower jaw. 1974-bakker and galton united dinosaurs and added birds as a monophyletic group. 1986 j. gautier of california acad. of sciences & paul serreno of u. of chicago establish dinosaurs as a clade.
