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FOSSIL POINTS TO TIME WHEN FISH WALKED ASHORE
By Jennifer Sym, PA
A 383-million-year-old fossil has given scientists an insight into a major evolutionary change: when fish first transformed fins into limbs.
It took six years of searches in the icy wilderness of the Canadian Arctic before the team unearthed the remains of the new species - an alligator-like fish with leg-like fins.
After they found the rock-covered ancient fish, now named Tiktaalik roseae, it was taken back to a lab and placed under a microscope where it was painstakingly picked apart from the rock with a needle.
It not only shows evidence of fish scales and fins, but also wrists, fingers, ribs and a neck like a land animal, and could help to show how fish first made the move from water to land.
The University of Chicago's Neil Shubin, who co-led the team, said: ``We did a few high fives when we uncovered the fossil, but there's only so much celebrating you can do in the Arctic.'' He added in an interview with National Geographic Magazine: ``This animal represents the transition from water to land - the part of history that includes ourselves.
``When we talk about the fish's wrist, we're talking about the origin of parts of our own wrist.'' Dr Ted Daeschler, curator of vertebrate biology at The Academy of Natural Sciences in Philadelphia, and a fellow leader of the expedition to Canada's Ellesmere Island, said: ``The find is a dream come true. We knew that the rocks on Ellesmere Island offered a glimpse into the right time period and were formed in the right kinds of environments to provide the potential for finding fossils documenting this important evolutionary transition.'' The fossilised creatures found by the group reach up to 10ft in length with jaw sizes ranging from 10 to 20 inches across.
The area is so inhospitable that the team could only work there for one month a year but, enduring 24-hour daylight, sleeting storms and polar bears, they were around a week's journey away from civilisation when they found the fossil, in 2004.
It is believed to have existed during the Devonian Period, which lasted from 417 million years to 354 million years ago.
The find, details of which are published in this week's edition of the journal Nature, is in such good condition that scientists have said it could become an ``icon of evolution in action'' as powerful as Archaeopteryx, which bridged the gap between reptiles and birds.
Jenny Clack, a land animal evolution expert from the University of Cambridge, said: ``It's the best fish-fossil found so far to show how the first land animals evolved. It confirms everything we thought and also tells us about the order in which certain changes occurred.'' Casts of the fossil's skull and fin will go on display in Antenna, the London Science Museum's science and technology news gallery, until early May 2006.
By Jennifer Sym, PA
A 383-million-year-old fossil has given scientists an insight into a major evolutionary change: when fish first transformed fins into limbs.
It took six years of searches in the icy wilderness of the Canadian Arctic before the team unearthed the remains of the new species - an alligator-like fish with leg-like fins.
After they found the rock-covered ancient fish, now named Tiktaalik roseae, it was taken back to a lab and placed under a microscope where it was painstakingly picked apart from the rock with a needle.
It not only shows evidence of fish scales and fins, but also wrists, fingers, ribs and a neck like a land animal, and could help to show how fish first made the move from water to land.
The University of Chicago's Neil Shubin, who co-led the team, said: ``We did a few high fives when we uncovered the fossil, but there's only so much celebrating you can do in the Arctic.'' He added in an interview with National Geographic Magazine: ``This animal represents the transition from water to land - the part of history that includes ourselves.
``When we talk about the fish's wrist, we're talking about the origin of parts of our own wrist.'' Dr Ted Daeschler, curator of vertebrate biology at The Academy of Natural Sciences in Philadelphia, and a fellow leader of the expedition to Canada's Ellesmere Island, said: ``The find is a dream come true. We knew that the rocks on Ellesmere Island offered a glimpse into the right time period and were formed in the right kinds of environments to provide the potential for finding fossils documenting this important evolutionary transition.'' The fossilised creatures found by the group reach up to 10ft in length with jaw sizes ranging from 10 to 20 inches across.
The area is so inhospitable that the team could only work there for one month a year but, enduring 24-hour daylight, sleeting storms and polar bears, they were around a week's journey away from civilisation when they found the fossil, in 2004.
It is believed to have existed during the Devonian Period, which lasted from 417 million years to 354 million years ago.
The find, details of which are published in this week's edition of the journal Nature, is in such good condition that scientists have said it could become an ``icon of evolution in action'' as powerful as Archaeopteryx, which bridged the gap between reptiles and birds.
Jenny Clack, a land animal evolution expert from the University of Cambridge, said: ``It's the best fish-fossil found so far to show how the first land animals evolved. It confirms everything we thought and also tells us about the order in which certain changes occurred.'' Casts of the fossil's skull and fin will go on display in Antenna, the London Science Museum's science and technology news gallery, until early May 2006.