🦖 Tyrannosaurs were also scavenging cannibals

The image of tyrannosaurs as supreme predators has just been shaken. A discovery indicates that these terrors of the Mesozoic also adopted opportunistic behaviors, not hesitating to feed on already available carcasses, including those of their own kind.

A recent investigation conducted at Aarhus University used three-dimensional scanning to examine a fossilized bone. This technique revealed sixteen bite marks on a metatarsal, a foot bone belonging to a large tyrannosaur dating back more than 75 million years. Examinations showed that these traces were made by a smaller tyrannosaur, indicating scavenging and cannibalistic behavior.


The team observed that the marks were located on a part of the foot low in flesh. This position, combined with the absence of signs of healing, indicates that the smaller animal was consuming the last remains of a carcass already heavily decomposed. Thus, even the hardest bony parts could constitute a meal at the end of the cycle.

To conduct this analysis, Josephine Nielsen, a master's student, worked on a digital model and a 3D-printed copy. The original bone, found in the Judith River Formation in Montana by an amateur, was not handled directly to avoid any damage. It is now preserved at the Badlands Dinosaur Museum in North Dakota.

The method used, including the CM classification system, provided new accuracy in the study of traces. By classifying each mark according to established criteria, paleontologists can now differentiate between various types of bites, from simple scratches to deep cuts. This transforms the examination of fossils into a detailed reconstruction of past behaviors.

The findings, published in the journal Evolving Earth, demonstrate that the prehistoric food chain was more malleable than imagined. Tyrannosaurs, beyond their status as hunters, also participated in recycling by ingesting all types of available remains.