Paleontologists have described in detail for the first time the scaly skin of Carnotaurus sastrei, an abelisaurid theropod that lived in South America during the Late Cretaceous epoch, sometime between 72 and 70 million years ago.
An artist’s reconstruction of Carnotaurus sastrei based on the scaly skin described by Hendrickx & Bell. Image credit: Jake Baardse.
The newly-described fossil of Carnotaurus sastrei was originally discovered in 1984 by the Argentine paleontologist José Bonaparte.
The skeleton, which came from Chubut Province of Patagonia, was preserved along with sheets of its scaly hide.
In a new study, Dr. Christophe Hendrickx from the Unidad Ejecutora Lillo and Dr. Phil Bell from the University of New England looked at the skin from the shoulders, belly and tail regions of Carnotaurus sastrei.
They found that the dinosaur’s skin was more diverse than previously thought.
“The scaly skin of this abelisaurid is the most completely preserved of any theropod and the only example of this form of integument known outside of Tetanurae, excluding footprints,” they said.
“The skin is preserved in the shoulder, thoracic, tail and, possibly, neck regions.”
“It consists of medium to large (2-6.5 cm in diameter) conical feature scales surrounded by a network of low and small (less than 1.4 cm) non-imbricating basement scales separated by narrow interstitial tissue.”
The fossilized skin of Carnotaurus sastrei. Image credit: Hendrickx & Bell, doi: 10.1016/j.cretres.2021.104994.
Unlike more recent discoveries of feathered dinosaurs, particularly from China, Carnotaurus sastrei was entirely scaly, with no evidence of feathers.
As an active predator, the authors suggest the scales would have been important in regulating the animals body temperature, as they do in modern reptiles.
“Given the presumed active lifestyle of Carnotaurus sastrei and the necessity of shedding excess heat, particularly at large body sizes (over 1,000 kg), we speculate that the skin may have played a vital role in thermoregulation; a role consistent with integument function in extant mammals and reptiles,” they said.
The team’s paper published in the journal Cretaceous Research.
Christophe Hendrickx & Phil R. Bell. 2021. The scaly skin of the abelisaurid Carnotaurus sastrei (Theropoda: Ceratosauria) from the Upper Cretaceous of Patagonia. Cretaceous Research 128: 104994; doi: 10.1016/j.cretres.2021.104994