Re: Bird and dinosaur ties put to test

Stephen Jones (sejones@ibm.net)
Sun, 17 Nov 96 17:28:16 +0800

Group

Here is another article from my local newspaper:

As Steve Clark (I think it was) pointed out the other day, even
feathers on a dinosaur does not automatically prove descent of birds
from dinosaurs - it could be convergence.

However, I would expect convergence to be a result of common
environmental factors and ways of life working on the same
underlying genetic code.

Therefore, I would accept that birds are probably descended from
a *reptile* common ancestor, but not necessarily from dinosaurs.

This latest fossil evidence indicates that "the ancestor of modern
birds first arose during the middle Jurassic or earlier periods" (ie.
early Jurassic of Triassic), which would well and truly predate the
usual candidate dinosaurs like Compsognathus.

God bless.

Steve

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Bird and dinosaur ties put to test

WASHINGTON

SCIENTISTS have unearthed new evidence challenging the theory that
birds descend from dinosaurs, according to the journal, Science.

Studying bird fossils found in north-eastern China, a team of researchers
wrote that birds may have originated much earlier than thought.

The fossils date to the late Jurassic and early Cretaceous periods about
140 million years ago.

The researchers said this suggested the ancestor of modern birds first
arose during the middle Jurassic or earlier periods.

Some scientists believe dinosaurs thought to be most like modern birds
date to the late Cretaceous period, about 76 million years later than the
fossil birds.

The researchers, which included senior university academics, said the
fossils pointed to a separation of birds into two distinct lines.

They said one line gave rise to modern birds and the other prospered and
diversified until they became extinct with dinosaurs at the end of the
Cretaceous period.

"The discovery that the line leading to modern birds coexisted almost
from the earliest occurrence of birds in the fossil record with an archaic
group of now extinct birds is the most important discovery in fossil birds
since Archaeopterys," one researcher said.

The toothed Archaeopterys was the first bird discovered to have lived
during the Jurassic.

The researchers based their findings on three fossil birds excavated in
Jurassic-Cretaceous deposits.

"Bird and dinosaur ties put test", "The West Australian", Saturday
November 16, 1996, p57)
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