Beaver or Otter, It Lived in Dinosaurs' Time

In the conventional view, the earliest mammals were small, primitive, shrewlike creatures that did not begin to explore the world's varied environments until the dinosaurs died out 65 million years ago.

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Mark A. Klingler/Carnegie Museum of Natural History

Scientists have found a fossil of a mammal — part beaver, part otter, part platypus — that lived in China 164 million years ago.

But scientists are reporting today that they have uncovered fossils of a swimming, fish-eating mammal that lived in China fully 164 million years ago, well before it was thought that some mammals could have spent much of their lives in water.
The extinct species appears to have been an amalgam of animals. It had a broad, scaly tail, flat like a beaver's. Its sharp teeth seemed ideal for eating fish, like an otter's. Its likely lifestyle — burrowing in tunnels on shore and dog-paddling in water — reminds scientists of the modern platypus.
Its skeleton suggests that it was about 20 inches long, from snout to the tip of its tail, about the length of a small house cat.
The surprising discovery, made in 2004 in the abundant fossil beds of Liaoning Province, China, is being reported in the journal Science by an international team led by Ji Qiang of Nanjing University.
In the article, Dr. Ji and other researchers from the Chinese-READ MORE-http://www.nytimes.com/2006/02/24/science/24beaver.html?_r=0