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Rotting fish experiments have helped to create picture of our early ancestors, says a study from the University of Leicester.
fossils from the early phase of vertebrate evolution are very rare because being completely soft-bodied they normally rotted away completely after death leaving nothing behind. But very occasionally their remains became preserved as fossils giving us a tantalising glimpse of our early vertebrate relatives.
Hagfish after 20 days of decay. Only the head skeleton, notochord and parts of the liver are left.
Phil Berardelli at Science writes:
The hardship seems to have been worth it. From their observations, the researchers were able to detail what they call a largely unknown "decay bias." That is, Sansom explains, the later-evolved parts of the body are lost soonest. In lampreys, for example, certain parts of the brain and the mouth that distinguish the animals from earlier relatives begin a rapid decay within 24 hours. Those missing structures, says Sansom, can cause researchers to misinterpret fossil organisms "as more primitive than they would have been in life," something that potentially skews evolutionary history.
The scientists wanted to examine the decaying process in order to understand the decomposition of soft-body parts in fish. This in turn will help them reconstruct an image of creatures that existed 500 million years ago.
