History Files
 

 

Mesozoic World

Cretaceous Duck in Antarctica

Edited from BBC News, 20 January 2005

In 2005 scientists were able to announce in the journal Nature that ducks may have been paddling about in primeval swamps when T rex was king of the dinosaurs.

Fossil remains of a bird which lived 70 million years ago appeared to belong to a relative of modern ducks and geese. The partial skeleton, discovered on Vega Island, western Antarctica, was likely to stir up controversy (Antarctica was located further north at the time and enjoyed cool but habitable summer temperatures). Many scientists of the time were of the opinion that modern bird lineages did not evolve until the end of the dinosaurs' reign.

Two camps

Although the first known primitive bird, Archaeopteryx, lived 150 million years ago in the Jurassic period, researchers disagreed over when modern birds made their first appearance. One camp believed that many modern bird lineages existed as long ago as 100 million years. According to this vision, familiar-looking birds would have been running and flying alongside dinosaurs.

In contrast, the other camp thought 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 were so far in support of the latter version, known as the 'big bang' theory of bird evolution. But if the new find, known as Vegavis iaai, really was a relative of the duck, it would lend considerable weight to the idea that modern birds lived with dinosaurs and survived the catastrophe which killed the 'terrible lizards'.

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 this point the fossil record had been ambiguous. But this fossil served to indicate that at least part of the diversification of living birds began before the extinction of non-avian dinosaurs.

Ancient chickens

If this species really was a duck, and it did live in the Cretaceous, then other modern birds probably did too. Chickens and their relatives belonged to the lineage that was closest to the duck lineage. If the duck lineage existed in the Cretaceous, the chicken lineage must also have been present. Even though a chicken fossil was yet to be found, its lineage must have been there.

  This is basically an unidentifiable bundle of bones

Professor Alan Feduccia  

However, Vegavis failed to convince supporters of the big bang theory of bird evolution. Alan Feduccia, a bird expert from the University of North Carolina, US, was of the opinion that 'this is basically an unidentifiable bundle of bones'.

In fact, he claimed that it was a well-known specimen that had been kicking around since 1992, one that was originally described as belonging to an extinct group. All of a sudden it was a modern duck and he was not at all convinced by the claim.

Sensitive to change

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 was unmoved by the interpretation. He thought that the analysis was based on very superficial features of bones; so he found it to be unreliable.

Professor Feduccia was 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. To him any claim that whatever caused the mass extinction had no effect on the birds seemed ludicrous.

 

 

     
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