ESC2000 Lecture Notes - Lecture 10: Mosasaur, Plesiosauria, Tyrannosaurus
Document Summary
Paleozoic ends with perma-triassic (750 million yrs. ago/p-1) mass extinction event. Nearly 90% of marine species go extinct. About 70% of terrestrial species go extinct. Dramatic increase in greenhouse gasses due to massive long term eruptions in siberia. Extreme quantities of methane clathrates led to the huge extinction of marine species. Triassic period - explosion of reptiles" diversification into major groups. End of triassic, pangea starting to break apart. 1st mammals - platypus still lays eggs today. Due to rifting between laurasia and gendwana as pangea breaks apart, resulting in massive eruptions of basaltic lava: camp => central atlantic magnetic province . Niche an organisms" ecological role in nature. Global climate still warm no polar ice caps - sea level very high. Inland seaway that bisects north america into eastern and western halves generalized monotremes (egg laying) marsupials (pouches) placentas (us) India has separated from gondwana and is an island continent.
