Missing Link
Say hello to our most bizarre ancestor — a part crocodile, part seal-like fish that was able to take the first baby steps on to land roughly 380 million years ago.
The discovery, 1,400 kilometres above the Arctic Circle, of fossilized skeletons of a creature dubbed Tiktaalik roseae is seen as filling a missing evolutionary link between fish and the first land animals.
The findings were announced yesterday by a U.S.-Canada team that included a University of Toronto graduate researcher.
Steve Cumbaa, a research paleontologist at the Canadian Museum of Nature in Ottawa not connected with the work, hailed the discovery.
"These are the first little baby steps on getting animals `out of ooze and born to cruise,'" Cumbaa said, quoting a catchphrase by American cartoonist Ray Troll.
Experts say that within a few million years Tiktaalik was followed by creatures completely adapted to terrestrial life, collectively called tetrapods. These then evolved into all the land animals on Earth today, including humans.
The discovery is important because it helps researchers reconstruct the detailed path of anatomical adaptation at a critical state of evolution.
University of Chicago paleontologist Neil Shubin, senior member of the research team, called Tiktaalik an "evolutionary mosaic" because the creature combines key elements of fish and land animals in a single body.
The crocodile-shaped head was able to shift from side to side without also moving the shoulders. As well, overlapping ribs provided support against gravity once the creature was out of the water.
"It could have breathed on land and done a sort of push-up with its fins but it couldn't have walked. It probably flopped like a seal," Shubin said in an interview.
Yet Tiktaalik, the Inuit word for "large freshwater fish," also sported scales and fins. But the front fins had bones similar to a shoulder, upper arm, elbow, forearm and a rudimentary wrist.
The largest of the three specimens stretches a little less than three metres, but is missing its tail.
In the period between 380 and 360 million years ago when animals made the move from oceans to land, the Canadian Arctic resembled the Amazon basin. Tiktaalik would have swum in gently meandering streams but could have made brief forays onto land, the researchers speculated.
The discovery, 1,400 kilometres above the Arctic Circle, of fossilized skeletons of a creature dubbed Tiktaalik roseae is seen as filling a missing evolutionary link between fish and the first land animals.
The findings were announced yesterday by a U.S.-Canada team that included a University of Toronto graduate researcher.
Steve Cumbaa, a research paleontologist at the Canadian Museum of Nature in Ottawa not connected with the work, hailed the discovery.
"These are the first little baby steps on getting animals `out of ooze and born to cruise,'" Cumbaa said, quoting a catchphrase by American cartoonist Ray Troll.
Experts say that within a few million years Tiktaalik was followed by creatures completely adapted to terrestrial life, collectively called tetrapods. These then evolved into all the land animals on Earth today, including humans.
The discovery is important because it helps researchers reconstruct the detailed path of anatomical adaptation at a critical state of evolution.
University of Chicago paleontologist Neil Shubin, senior member of the research team, called Tiktaalik an "evolutionary mosaic" because the creature combines key elements of fish and land animals in a single body.
The crocodile-shaped head was able to shift from side to side without also moving the shoulders. As well, overlapping ribs provided support against gravity once the creature was out of the water.
"It could have breathed on land and done a sort of push-up with its fins but it couldn't have walked. It probably flopped like a seal," Shubin said in an interview.
Yet Tiktaalik, the Inuit word for "large freshwater fish," also sported scales and fins. But the front fins had bones similar to a shoulder, upper arm, elbow, forearm and a rudimentary wrist.
The largest of the three specimens stretches a little less than three metres, but is missing its tail.
In the period between 380 and 360 million years ago when animals made the move from oceans to land, the Canadian Arctic resembled the Amazon basin. Tiktaalik would have swum in gently meandering streams but could have made brief forays onto land, the researchers speculated.
posted by Susanna Duffy @ 8:11 AM
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