Old Fossils To Solve The Mystery Of The First Birds To Extinction

Monday, October 17, 2011

Many of the early birds suffered from the catastrophic loss as well as dinosaurs, new research shows.

The impact of a meteorite which coincided with the disappearance of the dinosaurs 65 million years, has also seen a rapid decline of primitive birds.

Only one group of birds have survived thanks to the mass extinction, from which all modern birds are descended.

Researchers at Yale University published their findings in the journal PNAS this week.

There was a long debate over the fate of the first "archaic" birds, which first evolved about 200 million years.

It is the population decreased slowly towards the end of Cretaceous time, and suddenly the mass extinction at the Cretaceous-degree (KT) boundary is unresolved because of contradictory evidence.

DNA studies have attempted to date the origin of modern birds, with some suggesting they appeared before the extinction of dinosaurs, with many of them survive the extinction event.

But the molecular clock suffers from "methodological issues", said Dr. Rich Long at Yale University, and the well-dated fossils are needed 'stratigraphic control' is extinguished.

There are problems with the fossil record, however. It is incomplete because of the extreme rarity of fossil birds.

The bones of birds are very difficult to maintain in the form of fossils, as they are small and lightweight, and easily damaged or washed into the rivers.

But a new study led by Dr. Rich Long, has used fragmentary fossils of birds collected up to 100 years ago, which places all over North America.

The new diversity

The fossil beds in North and South Dakota and Wyoming in the United States, and Saskatchewan in Canada, the date from 1.5 million years of the Cretaceous period.

A more precise date of the bird fossil sites within the extinction 300,000 years - a very short period of geological time scales.

These fossils were studied before, but have been "stuck" in the modern groups based on their overall similarity.

Dr Rich Long and his team reanalyzed and reclassified these important fossil fragments, using the functions of the shoulder joint to attribute to modern and ancient fossil groups.

For more information related to dinosaurs, visit rareresource.com.


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