GEOL 11042 Lecture Notes - Lecture 35: Oligocene, Niche Differentiation, Miacidae
Document Summary
The fossil record is really very rich in cenozoic mammals, in part because there is such a rich record of fossil bearing sediments of cenozoic age, and in part because the bones tend to be well preserved. There are some big differences between reptiles and mammals in the skulls that can be seen right away. Jaw reptiles have several bones, mammals have one: teeth reptiles have undifferentiated teeth, mammals have differentiated teeth, ear bones reptiles have one, mammals have three. So about 15 million years after the k/t boundary, the mammals moved into all those available niches. What was special about the eocene: the eocene began warm and ended cool-it was the warmest epoch of the. Cenozoic, but it ended with a big cooling event: the mammal diversification occurred in the late eocene, during that cooling episode. This is the fourth time flight has evolved. Looking briefly at three successful cenozoic mammalian groups carnivores,