Posts Tagged ‘why giant mammals’
A study published in Science helps explain how mammals evolved worldwide to enormous sizes after the dinosaurs became extinct. During the first 140 million years of evolutionary history of mammals were small, from 3 grams to 15 kilograms, and occupied a very small ecological role. But, after the end of the Cretaceous extinction, about 65 million years, which led to the disappearance of the dinosaurs, mammals exploded both in size and ecological environment.
The authors, led by Felisa Smith, University of New Mexico in Albuquerque, say that the main driver appears to have been diversified to fill the vacant niches after the extinction of the dinosaurs. The upper limits to body size were most likely marked by the temperatures of the environment and available land area. Read the rest of this entry »