Footprints of the Triassic reptile Chirotherium, were first described in 1835 from Hessburg, Germany.

In December 1838, John Cunningham (a Liverpool architect) told the Geological Society of London that he had found similar footprints at Storeton Quarry, near Birkenhead on the Wirral.

Chirotherium footprints have now been found in several places in England. They are common in Cheshire's Triassic sandstone and can be seen at Daresbury, Flaybrick Hill, Hilbre Island, Oxton, Runcorn and Tarporley.

The footprints look like a human hand with a thumb on the outer edge. This led to the name Chirotherium or "Hand Beast".

Geologists first thought they were the handprints of an early ape or human. In 1889, James Howell argued that they were prints from a large amphibian.

It wasn't until 1925 that Chirotherium was recognised as a reptile.

Chirotherium lived in the Triassic period, 225 million years ago. This period was hot and dry. Cheshire was a desert with few trees. Thunderstorms would create flash floods and temporary lakes.

The fossils are casts of the original footprints. After rain, tracks in the lakeside mud would be covered with windblown sand. The sand would have become deeper, then squeezed over millions of years to form the Triassic sandstone.

At least six species of Chirotherium lived in Britain. However, we still do not know exactly what the animal looked like. Bones would have been eroded away by the acidic desert conditions.

The Grosvenor Museum in Chester has 45 specimens of Chirotherium footprints from the collection of Osmund Jeffs.