Dawn of the Dinosaurs: Life in the Triassic.DAWN OF THE DINOSAURS: Life in the Triassic NICHOLAS FRASER The Permian period Permian period (pûr`mēən) [from Perm, Russia], sixth and last period of the Paleozoic era (see Geologic Timescale, table) from 250 to 290 million years ago. ended 248 million years ago with the catastrophic extinction that laid the groundwork for the evolution of amphibians amphibians members of the animal class Amphibia. Includes frogs, toads, newts, salamanders and cecilians all capable of living on land or in water. and early dinosaurs. Fraser, a paleontologist, outlines the climatic changes and the evolution of flora and fauna that occurred during the subsequent Triassic. In part one, Fraser describes how certain geographic areas sustained life despite the Permian extinction and how early Triassic The Early Triassic (also known as Lower Triassic, Buntsandstein, or Scythian) is the first of three epochs of the Triassic period. It spans the time between 251 ± 0.4 Ma and 245 ± 1.5 Ma (million years ago). fish and tetrapods evolved into dinosaurlike creatures. In part two, he surveys a period of increased diversity among both plants and terrestrial animals. Part three describes the time when amphibians and reptiles in North America North America, third largest continent (1990 est. pop. 365,000,000), c.9,400,000 sq mi (24,346,000 sq km), the northern of the two continents of the Western Hemisphere. , the Elgin region, and Gondwana began to resemble modern-day creatures. Finally, the author presents evidence that the Triassic might have ended with a cataclysmic cat·a·clysm n. 1. A violent upheaval that causes great destruction or brings about a fundamental change. 2. A violent and sudden change in the earth's crust. 3. A devastating flood. event, such as a bombardment from space that wiped out the earliest mammals and first dinosaurs. Indiana Univ. Press, 2006, 307 p., color illus., hardcover, $49.95. |
|
||||||||||||||
Printer friendly
Cite/link
Email
Feedback
Reader Opinion