August 3, 2009

Fossils Reveal Massive Worms That Lived 475 Million Years Ago

The fossilized tracks of a giant marine worm that lived some 475 million years ago have been discovered byt the Spanish National Research Council (CSIC).

Evidence of the worm, which was up to 3 feet in length, was found in the Cabaneros National Park in central Spain.  The region was once a seabed during the Lower Ordovician period, the Spanish researchers said.

The CSIC said the worms dwelled within horizontal galleries 15 feet long and 6-8 inches in diameter under the seabed.  The fossilized galleries were the "oldest tracks of giant worms" ever discovered, and were surrounded "with mucous secretions to harden them and prevent their collapse, which has facilitated their preservation," said paleontologist Juan Carlos Gutierrez Marco. 

The tracks also pre-date those discovered in Devon, England, earlier this year, which were dated from 200 million years ago, the AFP news agency quoted Gutierrez Marcos as saying.

He explained how the worms could grow to such a large size.

"For more than 450 millions years ago our country was part of a marine platform of an ancient continent called Gondwana," he explained.

"The Iberian Peninsula was then near the south pole of the era. Organisms living in very cold water have a metabolism that allows them to grow bigger -- what is known as polar gigantism."