GGR305H1 Chapter Notes - Chapter 11: Northbrook Island, Cricetidae, Creodonta
5 Jan 2019
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Week 2: chapter 11 setting the scene for today. Until dinosaurs became extinct, mammals were confined to roles of small animals living mainly on invertebrates, fruits, and nuts. After dinosaur extinction, were able to occupy roles previously taken by dinosaurs and become dominant group of animals. Because mammals had already spread before dinosaur extinction, their nature of distinction was unique on each continent. Perpetuated by fact that mammals are unable to cross wide stretches of water. Taxa that evolve in a particular continent are normally confined to it, as endemic taxa. Possibilities for mammals to disperse varied due to changes in positions of continents, in climate, and rise and withdrawal of shallow seas. South america and africa largely isolated from other continents in late cretaceous and early. India and south-east asia had fauna similar to africa in late cenozoic. Different climatic histories and appearance of desert and mountains separating two areas led to divergence of mammalian fauna.
