Chirotherium “Hand Beast” – Tracks in the Mud

By | February 6th, 2008|Dinosaur Fans, Main Page, Palaeontological articles|0 Comments

Before Dinosaurs – Bizarre Hand-Prints Preserved

In the Triassic rocks of North America, Europe (including England) and Africa a number of trackways of strange footprints have been uncovered, the first trackway being discovered in Germany in the central state of Thuringia in 1834.  Although, individual footprints and trackways had been known to the scholars of the day for some time, these footprints were remarkable as they resembled the imprint of a human hand.   The footprints had five digits and the fifth digit (which in fact represents the equivalent of our little finger or toe), stuck out sideways and gave the impression of being poseable like our own thumbs.

At the time, the science of geology and the study of fossils were very much in their infancy.  These strange footprints were claimed to the imprints left by those unfortunate people not able to survive the Biblical flood.  Other educated people at the time speculated that they could have been the hand-prints of apes or monkeys.

Strange Fossilised Footprints

Picture Credit: L. B. Halstead

The footprint in the picture, certainly looks like the imprint of a human hand.  The trouble is these trackways have been found in sediments dated to the early Triassic around 240 million years ago.  Since the prints resembled human hands, scientists named the animal that could have made them Chirotherium “hand beast”.

No actual fossil bones or other remains have been found in association with these trackways.  In spite of this, palaeontologists have been able to provide an impression of what the animal may have looked like.  The hind prints are nearly twice the size of the front prints, the trackways are also narrow indicating an upright gait rather than the more typical sprawling gait of other reptiles.  There is no sign of a tail drag in any of the trackways so Ichnologists (scientists who specialise in studying footprints); have deduced that the tail was held well clear of the ground.

A Possible Body Plan of Chirotherium

Picture Credit: L. B. Halstead

Many years later a nearly complete skeleton of another reptile from similarly aged sediments was unearthed. This animal resembled the reconstructions of Chirotherium, it was an Archosaur in the region of 2-3 metres long.  This fossil find was named Ticinosuchus.  This fossil helped vindicate those palaeontologists who had depicted Chirotherium (sometimes also known as Cheirotherium) as a predatory ancestor of the dinosaurs with legs positioned directly under the body.

During the early and middle Triassic a number of different animal groups evolved and expanded to fill the ecological niches left after the Permian extinction.  As the dinosaurs evolved, they shared the world with other large reptiles such as Batrachotomus, a huge six metre long carnivore.  Similar in general build to the likes of Chirotherium (but much bigger) these fierce animals competed with the dinosaurs for places at the top of the food chain.  Huge “land crocodiles” such as Batrachotomus were very successful and their fossil remains have been found all over Pangaea.

Scale model of Batrachotomus: Dinosaur Toys for Boys and Girls – Dinosaur Models

However, these very large, predominantly quadrupedal predators eventually became extinct around 220 million years ago, perhaps they were no longer able to compete with the rapidly expanding bipedal Theropod dinosaurs.

We are grateful to Mike Batty, for pointing out to us that the accepted spelling for the footprints is Chirotherium.  The correct Greek spelling is Cheirotherium, a name we still use round the office, as it was the accepted name for a time; but scientific nomenclature principles state that the first name used as a descriptor should take precedence hence the use of Chirotherium in this instance.