GEOL 107 Lecture Notes - Lecture 28: Andrewsarchus, Hyracotherium, Global Cooling

• School: Queen's University
• Department: Geological Sciences and Geological Engineering
• Course: GEOL 107
• Professor: Guy M Narbonne

Document Summary

Cenozoic mammals - guilds and trends: background. We have seen that the early tertiary (paleocene and eocene) radiation of mammals took place during a global greenhouse that began in the jurassic. Tropical and subtropical floras from the equator to the poles. Global cooling event began in the eocene, reaching icehouse conditions at the eocene- Convergent evolution results in similarity of form amongst species that attempt to fill these roles (e. g. development of sabre-teeth by therapsid reptiles, marsupials, and placentals) These easily categorized ways of life that have evolved repeatedly among different taxonomic groups are called guilds (see cowen, 2005, p. 244-246) We will look at two examples: mammalian top carnivores (cowen, 2013, p. 226-230) Extinction of the dinosaurs left the top carnivore niche unfilled. In the paleocene and eocene) it was filled by crocodiles and terror birds (lecture 24) Beginning in the paleocene, we see three overlapping groups of mammalian carnivores: mesonychids (bizarre ungulates like andrewsarchus paleocene -eocene)