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 | | From: | Garrison Hilliard | | Subject: | Cretaceous duck ruffles feathers | | Date: | Sat, 22 Jan 2005 17:41:00 +0000 |
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 | Cretaceous duck ruffles feathers
Ducks may have been paddling about in primeval swamps when T. rex was king of
the dinosaurs, scientists have announced in the journal Nature.
Fossil remains of a bird that lived 70 million years ago appear to belong to a
relative of modern ducks and geese.
The partial skeleton, discovered on Vega island, western Antarctica, is likely
to stir up controversy.
Many scientists believe modern bird lineages did not evolve until the end of the
dinosaurs' reign.
Two camps
Although the first bird, Archaeopteryx , lived in the Jurassic period 150
million years ago, researchers disagree over when modern birds made their first
appearance.
One camp believes many modern bird lineages existed as long as 100 million years
ago. According to this vision, familiar looking birds would have been running
and flying about alongside dinosaurs.
In contrast the other camp thinks that, although birds did exist during the
Jurassic and Cretaceous periods, they were largely wiped out by whatever killed
the dinosaurs.
According to this theory, only a few lineages made it through the mass
extinction and, subsequently, these lonely survivors blossomed into all the
modern bird families we know today.
The fossil records so far support the latter version, known as the "big bang"
theory of bird evolution.
But if the new find, known as Vegavis iaai , really is a relative of the duck,
it would lend considerable weight to the idea that modern birds lived with
dinosaurs and survived whatever catastrophe killed them.
A team of scientists led by Dr Julia Clarke, from North Carolina State
University, US, said Vegavis belonged to the waterfowl family and was "most
closely related to Anatidae, which includes true ducks".
"Until now the fossil record has been ambiguous," said Dr Clarke. "But now we
have a fossil which indicates that at least part of the diversification of
living birds had begun before the extinction of non-avian dinosaurs."
Ancient chickens
If this species was a duck, and it did live in the Cretaceous period, then other
modern birds probably did too.
"Chickens and their relatives belonged to the lineage which was closest to the
duck lineage," Dr Clarke told BBC News website.
"So if we had the duck lineage in the Cretaceous, the chicken lineage must have
been present. Even though we don't have a chicken fossil yet, we know its
lineage must have been there."
However Vegavis has not managed to convince supporters of the big bang theory of
bird evolution.
"This is basically an unidentifiable bundle of bones," Alan Feduccia, a bird
expert from the University of North Carolina, US, said.
"This is a well known specimen which has been kicking around since 1992, and it
was originally described as belonging to an extinct group. And now all of a
sudden it's a modern duck."
Sensitive
Julia Clarke and her team used a statistical analysis of certain bone features
to identify Vegavis as a member of the duck family, but Professor Feduccia is
unmoved by their interpretation.
"The analysis is based on very superficial features of bones, so I find it
unreliable."
Professor Feduccia is sure that bird species could not have survived a major
global extinction en masse.
"Birds are very sensitive to any environmental disturbance - in fact they are a
good indicator of environmental problems.
"But these people don't believe whatever caused the mass extinction had any
affect on the birds, and that seems ludicrous."
Story from BBC NEWS:
http://news.bbc.co.uk/go/pr/fr/-/2/hi/science/nature/4187287.stm
Published: 2005/01/20 11:00:28 GMT
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