Saturday, December 12, 2015

Dinosaurs Took Less Time To Evolve Than Scientists Previously Thought

Prehistoric Times

Faster Evolution: Scientific American writes:  “Animals escaping from an erupting volcano 235 million years ago in northwestern Argentina. These species, found as fossils in the Chanares Formation, include early mammal relatives (the dicynodont Dinodontosaurus in the left background, and the cynodont Massetognathus in the left foreground) and early dinosaur precursors (Lewisuchus in the right background, and Lagerpeton in the right foreground). By measuring radioactive isotopes in zircons crystals from the volcanic ash, scientists were able to determine the precise age of this fossil assemblage.”
Photo Credit:Victor Leshyk
Source: Scientific American

One of the better characteristics of science is that it is self-correcting; when a new theory comes out, it replaces an older theory once considered valid. Such is now the case with how dinosaurs evolved from reptiles, says Laura Geggel for Scientific American, who writes: “Dinosaurs took less than 5 million years to evolve from their reptile predecessors, the early dinosauromorphs, a new study finds. The finding revamps the time line between the dinosaurs and early dinosauromorphs. Until now, researchers thought that it took at least 10 million to 15 million years for the early dinosauromorphs to evolve into dinosaurs. ‘It really narrows the amount of time between the appearance of these early dinosauromorphs and the first dinosaurs," said study co-researcher Randall Irmis, a paleontologist at the University of Utah and a curator of paleontology at the Natural History Museum of Utah. "Rather than there being 10 [million] or 15 million years between when the first dinosauromorphs show up and the first dinosaurs, now it's just 5 million years.’” [See Photos of the Early Dinosauromorph Site in Argentina]

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For more, go to [ScientAmer]