Earliest 'animals' buried by Pompeii-style ash fall

Hall Fellow Martin Brasier, Professor of Paleobiology and Tutor in Geology, has co-authored a remarkable new research report into the earliest-known ‘animals’.

Martin and his team from the Universities of Oxford and Cambridge, in collaboration with the Memorial University of Newfoundland, have discovered the fossilised remains of small rangeomorphs that may have been buried under a Pompeii-like deluge of ash in Newfoundland around 579 million years ago.

Rangeomorphs are bizarre frond-shaped organisms which lived 580-550 million years ago and are unlike any creature alive today. They are often described as 'fern-like' and where exactly they fit in the tree of life is unclear. Because they lived deep beneath the ocean where there would have been no light they are not thought to be plants but they may not have had all of the characteristics of animals.

“The fossilised 'babies' we found are all less than three centimetres long; many times smaller than the 'parent' forms, seen in neighbouring areas, which can reach up to two metres in length,” said Professor Brasier. "This new discovery comes from the very bottom of the fossil-bearing rocks, making it one of the oldest bedding planes to preserve 'animal' fossils in the whole of the geological record.”

“We think that, around 579 million years ago, an underwater 'nursery' of baby fronds was overwhelmed, Pompeii-style, by an ash fall from a volcanic eruption on a nearby island that smothered and preserved them for posterity.”

A report of the research will appear in the July issue of the Journal of the Geological Society.

For more information contact Jack Matthews of Oxford University's Department of Earth Sciences, at jack.matthews@earth.ox.ac.uk

Below: A rangeomorph fossil measuring just 17 millimetres in length. Credit: OU/Jack Matthews