Fossils of animals and plants can tell us a lot about life in the past. A small fragment of bone can help to rebuild a complete skeleton.

However, what if there are no remains of an animal except for its footprints?

Fossil footprints were first noticed in quarries in the early 19th century. William Buckland, the Oxford geologist, made tortoises and other reptiles walk across piecrust to compare their tracks with those from the quarries.

In the 1830s, tracks were found that looked like mammal footprints. The print was hand-like with four fingers and a thumb curling to one side. In 1835, J.J. Kaup in Germany named this mysterious, long-dead animal, Chirotherium, from Greek words meaning ‘hand beast’.

The rocks in which the footprints were found were dated back to the Triassic period, some 200 million years ago. No fossil bones were found with the footprints testing the imagination of the 19th century scientists.

It was suggested that large apes or bears had made the prints. One problem in picturing what the ‘hand beast’ looked like was that the thumb stuck outwards from the line of walk. This led to the idea of an animal that crossed its legs as it walked.

Closer study of the footprints showed that a reptile had made them.

In 1925, the German scientist Wolfgang Soergel matched the Chirotherium prints to the South African fossil remains of the Pseudosuchians, or ‘false crocodiles’. These also had outward turned little toes.

So was Chirotherium a ‘false crocodile’?

The story is far from complete. We still have not found any bones of this mysterious animal. Work on the fossil footprints and tracks continues to try and draw the ultimate picture of Chirotherium, the ‘hand beast’.

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