Joanna Carver, reporter
(Image: courtesy of Phil Anderson, University of Massachusetts Amherst; Michael Ryan and Eric Snively, Cleveland Museum of Natural History; model and images Martin R?cklin, University of Bristol)
The debate on the origin of teeth and jaws appears to finally be over, thanks to a few fossils of this prehistoric fish (yes, that's a fish).
The beauty above is Compagopiscis croucheri and it was a placoderm, a kind of fish that lived from the later Silurian period (about 444 million years ago) to the late Devonian period (about 360 million years ago). An international team of palaeontologists worked with physicists from Switzerland to bombard the fossil remains with high-energy X-rays, so revealing the structure and development of the Compagopiscis's teeth.
Previously, sharks were believed to be the first vertebrates to develop teeth and jaws - it was believed that placoderms had no teeth. Early jawed vertebrates were thought to use scissor-like teeth, but this new research shows that pearly whites go back a lot further than previously believed, and in fact evolved alongside jaws.
"This is solid evidence for the presence of teeth in these first jawed vertebrates and solves the debate on the origin of teeth," said co-author Zerina Johanson of the Natural History Museum, London.
"Now we can test all the scenarios about the evolution about jaws and teeth," said Martin R?cklin from the University of Bristol, UK, the study's lead author. "It's thought that jaws and teeth are a key part of the evolution in vertebrates."
Journal reference: Nature, DOI: 10.1038/nature11555
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