BIOL 2030 Lecture Notes - Lecture 18: Dinos, Color Vision, Ornithischia
Document Summary
1: why are reptiles successful, reptilian orders, dinosauria, introduction. Earliest known reptile early permian (~300 mya, million years ago) Nonavian reptile members includes ~9500 species, over 300 species in north america. Reptilian orders: testudines (turtles, squamata (lizards and snakes, crocodilia (gators and crocs, sphenodonta (tuataras) Amniota (amniotes) land-living vertebrates that have an amnion around the developing embryo. Embryonic egg is characterized by four extra-embryonic membranes: amnion embryonic membrane surrounding the embryo, allantois functions in respiration and excretion. A pouch that allows gas exchange and excretion of nitrogenous wastes. All membranes allow oxygen and carbon dioxide to enter/exit: chorion double membrane surrounding the embryo, yolk sac encloses yolk. The amniotic egg plays a big role in internal fertilization: integument. Thin epidermis lies above the scales and sheds periodically. Osteoderm bony plates underneath the scales in crocodiles and some lizards: hinges that allows reptiles to move, ventilation.
