An illustration of a fossil containing Chirotherium tracks. Chirotherium (also known as Cheirotherium) or ‘hand-beast’, is the name of a creature which may be known only from fossil imprints of its tracks (trace fossils). These look, by coincidence, remarkably like the hand of an ape/human or bear, with the outermost toe having evolved to extend out to the side like a thumb, although probably only providing a firmer grip in mud. Its tracks were first found in 1834, in red sandstone in Thuringia, Germany, dating from 240 million years ago (mya). This creature was probably an archosaur, related to the ancestors of the dinosaurs.
L. Brent Vaughan Hill's Practical Reference Library Volume II (NewYork, NY: Dixon, Hanson and Company, 1906)