ANTHRO 101 Lecture Notes - Lecture 14: East Los Angeles College, Postorbital Bar, Dentition
Document Summary
Late triassic to early jurassic first mammals evolved, dinosaurs rule. 65 mya (end of cretaceous), dinosaurs disappeared start of mammal radiation (adapting to various environments) Plesiadapiforms the first primates (65-54 mya) No post-orbital bar and no opposable big toe. Have a mixture of traits some are derived. Influence vegetation, habitats, environment lead to specific adaptations. Primates used to have a larger habitat range. As climate changed, they moved towards warmer areas eocene (55 mya) Specific dental formula help identified nwm and owm ancestors. African natives, then moved to asia and europe. Then a decline, so they moved to asia and europe. Preserved remains or traces of plants, animal from the remote past. Environmental conditions must be just right to fossilize. Gives fossil sequence, and complements absolute dating (older or younger) Lithostratigraphy: massive catastrophic event (e. g. , volcanic eruption) can be helpful as one single layer must come from a single event (i. e. , deposited at the same time)
