Fossilised ‘Fern’ Reveals Prehistoric Treetops
From New Scientist
At 8 metres long, it had to be hauled out of the ground with a hydraulic lift normally reserved for dinosaurs. But this fossil formed around 385 million years ago - long before dinosaurs even existed.
It’s a tree from the Gilboa fossil forest, New York. The site - which contains the oldest trees in the fossil record - is well known to palaeontologists, who until now had only uncovered fossil tree stumps, leaving them guessing about the appearance of the tree tops.
Now they know: the trunk had large branches, with fronds similar to a modern-day tree fern - although they were unrelated to tree ferns. The fossil tree has been assigned to a group of plants known as cladoxylopsids (Nature, vol 446, p 904).
A forest of such trees would have provided a rich habitat for other organisms, as well as boosting ancient Earth’s biodiversity, says team member Chris Berry of Cardiff University, UK. Indeed, fossils of millipede-like detritivores were found at the site.
Such forests may also account for the drop in atmospheric carbon dioxide levels seen in the fossil record around that time. "The rise of forests must have had some impact on atmospheric carbon dioxide and therefore the Earth system," says Berry.
From issue 2600 of New Scientist magazine, 18 April 2007, page 17
Albert Gnidican/NY. State Museum.
