Low tide
Aut.MISBetley, CC-BY-NC
It was a warm afternoon on an estuary, 168 million years ago. The mud was soft, still wet from the tide. Something large — eight metres long, two metres tall at the hip, moving on two legs with a stride of roughly two metres — passed through. A megalosaur, or something close enough to one that the distinction hardly mattered in the moment. It was not in a hurry. It was not fleeing anything. It simply walked, pressed its three-toed foot into the silt, and moved on, unbothered and almost certainly not thinking about posterity.
The mud hardened. The sea came back, and left, and came back again, for an inconceivable number of times. The continent drifted. The animal's entire lineage disappeared. The print stayed.
I crouched over it on a grey Scottish afternoon, and took a photograph. The track filled slowly with water while I watched. Fifty-three centimetres of absence. Until the next low tide.