RAZD
Member (Idle past 1435 days) Posts: 20714 From: the other end of the sidewalk Joined: 03-14-2004
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Message 11 of 12 (445515)
01-02-2008 6:15 PM
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NEW WHALE (where's randman ...)
http://dsc.discovery.com/news/2007/12/19/whale-ancestor.html
quote:
It sounds like a stretch, but a new study suggests that the missing evolutionary link between whales and land animals is an odd raccoon-sized animal that looks like a long-tailed deer without antlers. Or an overgrown long-legged rat. The creature is called Indohyus, and recently dug up fossils reveal some crucial evolutionary similarities between it and water-dwelling cetaceans, such as whales, dolphins and porpoises. Newer fossils point to the deer-like Indohyus. The animal is a "missing link" to the sister species to ancient whales, said Hans Thewissen, an anatomy professor at Northeastern Ohio Universities College of Medicine. "As a zoo animal, it looks nothing like a whale," Thewissen said. But, he added, when it comes to anatomical features, the Indohyus "is quite strikingly like one." The key finding connecting Indohyus to the whale is its thickened ear bone, something only seen in cetaceans. An examination of its teeth showed that the land-dwelling creature spent lots of time in the water and may have fed there, like hippos and whales. Also, the specific positioning and shape of certain molars connects Indohyus to the earliest whales, which are about 50 million years old, Thewissen said.
With pictures: Error 404 (Not Found)!!1 Video:
Videos
| Nature Nature article (abstract): Whales originated from aquatic artiodactyls in the Eocene epoch of India | Nature
quote:
Although the first ten million years of whale evolution are documented by a remarkable series of fossil skeletons, the link to the ancestor of cetaceans has been missing. It was known that whales are related to even-toed ungulates (artiodactyls), but until now no artiodactyls were morphologically close to early whales. Here we show that the Eocene south Asian raoellid artiodactyls are the sister group to whales. The raoellid Indohyus is similar to whales, and unlike other artiodactyls, in the structure of its ears and premolars, in the density of its limb bones and in the stable-oxygen-isotope composition of its teeth. We also show that a major dietary change occurred during the transition from artiodactyls to whales and that raoellids were aquatic waders. This indicates that aquatic life in this lineage occurred before the origin of the order Cetacea.
Can you say muskrat? Enjoy. Edited by RAZD, : added refs
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