Earliest animal tracks yet found discovered by Exeter DPhil student
A researcher from Exeter College has found what is believed to be the oldest evidence for animal locomotion in the fossil record. Alex Liu (2007, Palaeontology) and his collaborators report in the journal Geology on a series of fossilised trackways from Newfoundland, Canada, which are 565 million years old. The structure of these impressions, recording the movement of an early organism across the deep sea floor, suggests that they were likely to have been created by a creature with muscular tissue – a feature which is only known today in animals. The beast would probably have moved in a manner similar to that of modern sea anemones.
If this interpretation is correct, it has important consequences for the study of animal evolution, suggesting that rather than a rapid “explosion” of animal diversity around 540 million years ago, as previously suggested by the fossil record, animals have a much more gradual evolutionary history stretching back at least 20 million years earlier. Alex now intends to search for further evidence of animals in rocks of that age, both in Canada and the U.K., in order to further constrain the early evolution of life on Earth.