Lizards detaching their tails to escape predators is a common occurrence in current times, but it turns out that reptiles that lived 289 million years ago also had similar traits.
Published in journal Scientific Reports is a new study by researchers at University of Toronto Mississauga and colleagues wherein they have shown how a group of small reptiles who lived 289 million years ago could detach their tails to escape the grasp of their would-be predators. The findings indicate that this kind of behavior is the oldest of its kind ever.
The reptiles, called Captorhinus, were rather small and weighed less than 2 kilograms. They were abundant in terrestrial communities during the Early Permian period and are distant relatives of all the reptiles today. These reptiles would most likely had to scrounge for food while avoiding being preyed upon by large meat-eating amphibians and ancient relatives of mammals. One of the methods they adopted to diver the attention of predators was to detach their tails like their modern day relatives.
Scientists were able to come to this conclusion after examining more than 70 tail vertebrae — both juveniles and adults — and partial tail skeletons with splits that ran through their vertebrae. They compared these skeletons to those of other reptilian relatives of captorhinids, but it appears that this ability is restricted to this family of reptiles in the Permian period.
Using various paleontological and histological techniques, the authors discovered that the cracks were features that formed naturally as the vertebrae were developing. Interestingly, the research team found that young captorhinids had well-formed cracks, while those in some adults tended to fuse up. This makes sense, since predation is much greater on young individuals and they need this ability to defend themselves.
It is likely that these cracks acted like the perforated lines between two paper towel sheets, allowing vertebrae to break in half along planes of weakness, scientists explain.