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Burren fossils gives scientists information on Earth’s climate

This article is from page 12 of the 2013-11-05 edition of The Clare People. OCR mistakes are to be expected so download the original SWF or the rendered page 12 JPG

A MICROSCOPIC extinct creature is providing scientist in the Burren with groundbreaking information about the climate on planet Earth, millions of years before the dawn of man.

Hundreds of tiny conodont fossils have been discovered in the limestone around Lisdoonvarna in North Clare. Using cutting-edge techniques, experts have been able gather information from the fossils which is helping them to map the rising and falling of sea levels during ancient ice ages.

Initial research into the Irish conodont indicates that in prehistoric times planetary cooling took place at a much earlier date than had been previously believed. This research is providing scientists with a new picture of how the climate operated on earth – hundreds of millions of years ago.

Dr John Murray of NUI Galway and Milo Barham carried out research St Brendan’s Well in Lisdoonvarna and at a number of conodonts hot-spots along the west coast.

“If you could go back in time about 500 million years ago and throw a net into the sea off the Clare coast, you’d probably pull out hundreds of these conodonts. They were so prolific in the past but they were so tiny, they are largely an enigma,” said Dr Murray.

“When you drive through the Burren you notice the terraced landscape. All of those big terraces were deposited when sea levels rose and fell and rose again over million of years. The reason for these rises and falls in sea level, is the world falling into and out of ice ages.

“We took a look at the oxygen isotopes, which we found in the conodonts, because this can give us an indication of the temperate in which that creature lived. We have published two papers on this subject and we are currently preparing a third and this paper is looking very closely at the chemical composition of the conodonts and also the evolution of the species. But we are still working on that paper.

“The real problem at the moment is the speed at which climate change is taking place. Milo’s work established that the cooling of the planet happened much earlier that anyone had previously thought, and much of that knowledge is down to these Irish conodonts.”

Conodont are tiny fossils, usually of just one millimeter in size, which are found in limestone. Up until recently, little has been known about the creatures, because the fossils usually only preserve records of their teeth.

Indeed, it was once thought that conodont and humans might have a shared ancestry as their teeth structure is similar to our own. Over the last decade however, scientists have discovered that conodonts are actually eel-like animals, which lived in large numbers in sea water.

Conodonts had teeth but no jaws, similar in ways to lamprey eels, and lived between 500 million years ago and 200 million years ago.

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