Science News

Earth's oldest rainforest discovered in coal mine and why the plucky T. rex is a bit “chicken”

A 300 million year old fossilized forest has been discovered in a coal mine in Illinois, USA. Covering an area of 10 square kilometres, its the largest fossil rainforest ever discovered and contains a diverse selection of extinct flora.

So how does a forest end up in a coal mine and what can the extinct flora tell us? Researchers from the UK and US team believe that a large earthquake shook the forest causing a large area of it to fall below sea-level it became peat and then coal. Dr Howard Falcon-Lang from the University of Bristol, UK, said “It was an amazing experience. We drove down the mine in an armoured vehicle, until we were at a hundred metres below the surface. The fossil forest was rooted on top of the coal seam, so where the coal had been mined away the fossilized forest was visible in the ceiling of the mine. We walked for miles and miles along pitch black passages with the fossil forest just above our heads.”

The find will have two major implications for current knowledge; the first concerns the coal in the mine and the other the plants. Not all coal is the same – coals are formed by different plants in different environments and this also effects the way they burn. By studying the coal from the mine, geologists will learn more about the period when they were buried, which happens to be at the height of peat formation. The plants in this rainforest are an unusual array of club mosses over 40 metres high which tower over a canopy of tree ferns, there are shrubs and tree-sized horsetails. It reveals information about the ecological preferences and community structure of such ancient plants; something which hitherto unknown.

It been a big fortnight for archaeological news as the discovery of some 68 million year old T. rex bones has been found to contain protein – changing current thinking on the fossilization process and proving birds are dinosaurs.

Scientists from the US have found collagen proteins in the bones, which when compared to those of living animals showed it to be structurally similar to chicken collagen. This finding has major implications for fossilization theories as up until now it was thought that organic matter would have decayed completely after a maximum if 100,000 years, the proteins gradually being replaced by mineral. Comparison of the fearsome T. rex's protein sequence have shown it to be structurally similar to the modern chicken, this provides evidence for the long-standing idea that birds are a group of dinosaurs (known as 'avian therapods') who survived the mass extinction which wiped out the other types of dinosaur. To date, this supposition had been based on the similarity of the architecture of their bones rather than, know researchers know this is true on the basis of related sequences.

29th Apr 2007