Fish fossils found in Nunavut bridge evolution gap

Paleontologists have found fossils of a newly-discovered species on Nunavut's Ellesmere Island that provide a key look at the evolution of fish into land animals.

The creature, which lived 375 million years ago, has been dubbed Tiktaalik roseae, and represents a long-sought link to the time when animals were first moving out of the primordial ocean and onto land, say scientists.

The three well-preserved specimens each have a head that looks like a crocodile and a body like a fish, and they range in length from one metre to 2.5 metres.

The fossils were found by Edward Daeschler of the Academy of Natural Sciences in Philadelphia, Neil Shubin of the University of Chicago, Farish Jenkins Jr. of Harvard and their colleagues. Their findings appear in the journal Nature on Thursday.

They found the fossils in the rocks of Ellesmere Island in 2004 after a four-year search in the area. Shubin said the Geological Survey of Canada mapped the island in the 1970s, but no one had really explored it.

After the fossils were found and excavated, they were sent to a lab to free them from the surrounding rock, a process that took about a year.

The new animal shows both fish and animal traits, with the scales and fins of a fish, but the ribs, neck, head and appendage bones are like those of a land animal.

The researchers said Tiktaalik was probably a poor swimmer, but would have been able push its body off the ground, moving on land like a seal.

Fossils of creatures having both fish and land animals features have been found before, but Tiktaalik falls into a gap between 385 million and 365 million years ago, giving researchers more details of the transition.

The name Tiktaalik comes from a word in the Inuktitut language, meaning large, shallow water fish. The name was supplied by Inuit elders in Nunavut.

Researchers had to brave cold, wind, and watch out for wandering polar bears during their search of Devonian-era rock formations on Ellesmere Island, far above the Arctic Circle.

A life-sized model of the fossil has been sent to the Nunavut government and the Canadian Museum of Nature in Ottawa. The researchers plan to return the fossils themselves to Canada. They'll be held in Ottawa until a place is ready for them in Nunavut.