Earth Sciences 2266F/G Lecture Notes - Lecture 27: Marsupial, Ecomorphology, Metatheria
26 Jul 2016
School
Department
Course
Professor
Document Summary
After we talk about the primitive/early mammals, most of them are mesozoic in age we talked about the origin/divergence between placental and marsupial mammals, around the same age as feathered dinosaur fossils. Even in some of the fossils in na also are marsupial fossils. Placental mammals arose in cretaceous and should have better ability to raise young, so theoretically placental mammals have a huge advantage over marsupials nowadays but in. So marsupial mammals are really abundant around this time. Radiation of placental mammals began in eocene people describe it as an explosive radiation, where all species just come out at the same time. Something to do with the empty niche left by the dinosaurs, so a lot of opportunity to adapt since there are no opportunities; thus very quick evolution. The red line near the paleocene and eocene boundary: you can see all the major groups suddenly emerging all at the same time.
