What it is
The animal that left the footprints at Corncockle Muir, in Dumfriesshire, Scotland, the first fossil footprints ever described by science. Nobody has found its bones, so the chapter shows a reconstruction. The tracks themselves are named Chelichnus.
Climbing a dune
The sandstone formed from desert dunes in the Permian. The quarrymen told Henry Duncan the tracks always ran up or down the sloping beds. On the way up, the claws dug in deeper, and each step pushed a small crescent of sand out behind the heel. Each front print shows up to five short toes on one rounded sole, about two inches across.
Not a tortoise
William Buckland matched the prints to his tortoises. A modern 3D scan of the Chelichnus duncani type slab found a ridge between the tip and the base of the toe marks. That is one reason experts now class these tracks with the therapsids, early relatives of mammals.
Read the sources
- History of ichnology: the correspondence between the Reverend Henry Duncan and the Reverend William Buckland · Ichnos (2007)
- Mujal et al., Frontiers in Earth Science 8:248 (2020)
- Reclassification of vertebrate trackways from the Permian of Scotland and related forms from Arizona and Germany · Journal of Paleontology (1996)