Australasian Science: Australia's authority on science since 1938

Footprints in Time

By John Long

Tetrapod trackways are helping to decode the behaviour of these Devonian creatures.

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I write this column from the blustery wind-swept coast of Valentia Island, a small island off the west coast of Ireland. I’m here studying some of the oldest known undisputed tetrapod trackways in the world, dating back to Middle Devonian times about 385 million years ago. The tracks are beautifully preserved, and show evidence of a large newt-like animal, just under a metre long, that has left large feet and small hand impressions.

Up until a month ago there was only one trackway known from the region, and it has become a real tourist attraction on the island. There is an arrow sign saying “Tetrapod Tracks” from the main road, and when you arrive another sign announces you are in the “Tetrapod Carpark”. Then another sign written in English and Gaelic directs you to the tetrapod track site. A beautifully crafted interpretation sign tells you about the significance of the site.

Finally you arrive at the beach and a metal railing separates you from the large flat bed of rock containing hundreds of individual prints of animals that once swam in shallow water through a river, their limbs gently caressing the ripple-marked bottom of the stream bed to leave a regular pattern of traces. Here you can see large foot traces interspersed with smaller hand traces. In one place the tracks are cut across by another animal, heading at a right angles to the main...

The full text of this article can be purchased from Informit.