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Unformatted text preview: GLY1101: Study Guide Nr. 3 1 Phanerozoic Eonothem: This Eonothem is often referred to as the time of "Visible Life". Organisms with skeletons or hard shells appeared by the first time in the geological record. The Phanerozoic Eonothem spans from 543 mya through today. The Phanerozoic is divided into three Erathems, from older to younger: Paleozoic, Mesozoic, and Cenozoic. The Mesozoic Erathem: 248 to 65 mya The Mesozoic is divided into three time systems: the Triassic (245 208 Million Years Ago), the Jurassic (208 146 Million Years Ago), and the Cretaceous (146 65 Million Years Ago). Mesozoic means "middle life ", and is the time during which the world fauna changed drastically from that which had been seen in the Paleozoic. Dinosaurs, which are perhaps the most popular organisms of the Mesozoic, evolved in the Triassic, but were not very diverse until the Jurassic. Except for birds, dinosaurs became extinct at the end of the Cretaceous. Some of the last dinosaurs to have lived are found in the late Cretaceous deposits of Montana in the United States. The Mesozoic was also a time of great change in the terrestrial vegetation . The Lower Mesozoic was dominated by ferns, cycads, ginkgophytes, bennettitaleans, and other unusual plants. Modern gymnosperms, such as conifers, first appeared in their current recognizable forms in the early Triassic. By the middle part of the Cretaceous System, the earliest angiosperms had appeared and began to diversify, largely taking over from the other plant groups. The breakup of Pangaea can be divided into four stages: a. The first stage involved the separation of North America from Africa during the Late Triassic, followed by the separation of North America from South America. b. The second stag e involved the separation of Antarctica, India, and Australia from South America and Africa during the Jurassic. During this stage, India broke away from the still united Antarctica and Australia landmass. c. During the third stage , South America separated from Africa, while Europe and Africa began converging. d. In the last stage , Greenland separated from North America and Europe. The Lower Mesozoic = Triassic + Jurassic Sytems The Lower Mesozoic is an informal division of the Mesozoic Erathem which includes the lower two systems: the Triassic and the Jurassic. See Chronostratigraphic Chart Paleogeography: Triassic <http://www.scotese.com/newpage8.htm > Jurassic <http://www.scotese.com/jurassic.htm > Cretaceous <http://www.scotese.com/cretaceo.htm > Summary of Lower Mesozoic Events: Important facts in the history of Mesozoic life The Mesozoic is divided into three time systems: the Triassic (245 208 Million Years Ago), the Jurassic (208 146 Million Years Ago), and the Cretaceous (146 65 Million Years Ago)....
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This note was uploaded on 12/19/2011 for the course HISTORY 1101 taught by Professor Josef.longoria during the Fall '10 term at FIU.
- Fall '10