Ancient Fish-like Animal Could Walk on Land

Posted on April 4, 2006

Scientists have discovered the fossil remains a creature that may help explain the mystery of how animals moved from the sea to land. The creature, called Tiktaalik, looks like a cross between a fish and a crocodile. It was probably able to both walk on land and swim. The AP reports that scientists believe Tiktaalik was able to briefly leave the water and move about on land.

Scientists have caught a fossil fish in the act of adapting toward a life on land, a discovery that sheds new light on one of the greatest transformations in the history of animals.

Researchers have long known that fish evolved into the first creatures on land with four legs and backbones more than 365 million years ago, but they've had precious little fossil evidence to document how it happened.

The new find of several specimens looks more like a land-dweller than the few other fossil fish known from the transitional period, and researchers speculate that it may have taken brief excursions out of the water.

The creature was discovered on Ellesmere Island in northern Canada. Paleontologist Neil Shubin, one of the discoverers of the fossil, said the creature moved on land like a seal.
About 375 million years ago, the creature looked like a cross between a fish and a crocodile. It swam in shallow, gently meandering streams in what was then a subtropical climate, researchers say. A meat-eater, it lived mostly in water.

Yet, its front fins had bones that correspond to a shoulder, upper arm, elbow, forearm and a primitive version of a wrist, Shubin said. From the shoulder to the wrist area, "it basically looks like a scale-covered arm," he said.

"Here's a creature that has a fin that can do push-ups," he said. "This is clearly an animal that is able to support itself on the ground," probably both in very shallow water and for brief excursions on dry land. On land, it apparently moved like a seal, he said.

It looks almost like a giant salamander. The article says the scientists plan to return to the same area and look for more fossils. That sounds like a really good idea.

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