Three rotting fish heads. Colours are caused by interference between the experimental equipment and the light illuminating the specimens. Picture courtesy Mark Purnell, Rob Sansom, Sarah Gabbott, University of Leicester
Palaeontologists from the Department of Geology at the University of Leicester have devised a new method of extracting information from 500 million-year-old fossils – studying rotting fish.
Boffins at the University studied the decomposing fish to gain a clearer picture of how our ancient fish-like ancestors would have looked.
Fish-like fossils from half a billion years ago are recognised as being part of our evolutionary history because they possess characteristic anatomical features, such as a tail, eyes and the precursor of a backbone.
The scientist’s methods, which are usually the domain of forensic scientists, have produced results that show how some of the earliest fossils from the human evolutionary tree may have been more complex than previously thought.
Four rotting fish. A sequence of images showing how the characteristic features of the body of amphioxus, a close living relative of vertebrates, change during decay. Picture courtesy Mark Purnell, Rob Sansom, Sarah Gabbott, University of Leicester
“Interpreting fossils is in some ways similar to forensic analysis,” explains Dr Rob Sansom. “We gather all the available clues to put together a scientific reconstruction of something that happened in the past.
“Unlike forensics, however, we are dealing with life from millions of years ago, and we are less interested in understanding the cause or the time of death.
“What we want to get at is what an animal was like before it died and, as with forensic analysis, knowing how the decomposition that took place after death altered the body provides important clues to its original anatomy.”
The results published today (January 31 2010) in the magazine Nature, show that some of the characteristic anatomical features of early vertebrate fossils have been badly affected by decomposition, and in some cases may have rotted away completely. Knowing how decomposition affected the fossils means reconstructions of our earliest ancestors will be more scientifically accurate.
