Study spotlights Gilboa fossil forest
Researchers in the United Kingdom and the United States have discovered and analysed a complete fossil forest as old as 385 million years. Presented in the journal Nature, the findings of the study shed new light on the Gilboa fossil forest, located in the Catskill Mountains in New York State. Scientists have referred to Gilboa as the oldest fossil forest, but research did little to reveal much about it... until now. During an excavation performed nearly a century ago to develop the Gilboa dam, a team identified fossils of hundreds of large tree stumps (the 'Gilboa' tree) preserved in rocks. But little data was recorded about the geological context of the fossil stumps, the soil the trees were growing in and the spacing of tree bases. The excavated quarry was backfilled after the dam was finished. This latest study was the first to investigate the Gilboa fossil forest. Past studies focused specifically on museum specimens and from tiny exposures of other levels in nearby streams. When the quarry was partially emptied to help workers complete maintenance work on the dam two years ago, researchers and contractors monitored the site. Professor Bill Stein of Binghamton University in the United States and Frank Mannolini, a palaeontology collection technician at the New York State Museum in the United States, discovered that the original quarry floor had been exposed, and that the roots and positions of the trunk bases had been preserved. Says Dr Chris Berry of the School of Earth and Ocean Sciences at Cardiff University in the United Kingdom and one of the authors of the study: 'For the first time we were able to arrange for about 1,300 square metres to be cleaned off for investigation. A map of the position of all the plant fossils preserved on that surface was made.' According to the researchers, the bases of the Gilboa trees are bowl-shaped depressions, whose diameters reach almost two metres. Thousands of roots surround the depressions. They add that they are the bases of trees up to 10 metres in height, and they describe them as being similar to palm trees or tree ferns. The team also identified several woody stems lying in horizontal positions. Their thickness was about 15 centimetres. They say the stems are like the ground-running trunks of Aneurophytalean progymnosperm, another type of plant. The researchers also discovered a large example of a tree-shaped club moss, which is a tree that forms coal seams in younger rocks found in both Europe and North America. 'All this demonstrates that the 'oldest forest' at Gilboa was a lot more ecologically complex than we had suspected, and probably contained a lot more carbon locked up as wood than we previously knew about,' Dr Berry explains. 'This will enable more refined speculation about the way in which the evolution of forests changed this Earth. Personally, the chance to walk on the ancient forest floor, and to imagine the plants that I have been studying as fossils for more than 20 years standing alive in the positions marked by their bases, was a career highlight. Seven years ago colleagues Linda (VanAller Hernick) and Frank found us a fossil of a complete Gilboa tree. That was amazing. But this time we've got the whole forest!'For more information, please visit:Cardiff University:http://www.cardiff.ac.uk/Nature:http://www.nature.com/
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United Kingdom, United States