In American history, tyrannosaurs are known for their four-toed hind limbs, with a small, degenerated dewclaw. Their tooth marks span 72–66 million years, meaning the end of the Cretaceous period was when dinosaurs last had their teeth shed. This shedding is believed to be caused by the formation of such iconic ecosystems, specifically on the parts of their mouths where tyrannosaurs fed. The study was published in the journal PLOS One.
Illustration of the construction of the tyrannosaur toothbone. Charles R. Knight, 1897
Did you know about tyrannosaurs?
A study was conducted on forms of Tyrannosaurus, the largest of the plant-eating dinosaurs, which could reach a height of fifteen tons. From three hundred research results, it is clear that only about 0.4 proportion of small teeth were found, which could be unmistakably identified by the teeth of the tyrannosaur, as they were the main cause of the death of other dinosaurs or crocodiles, which also moved in this environment.
Tooth marks on the bones of a deceased dinosaur. Siviero et al. / PLOS One, 2026
The teeth of dinosaurs did not have shed often, so the cause of their death was not the wear of their teeth, but their breakage. Based on this, scientists found signs that the teeth of dinosaurs like this were not shed, but, most importantly, their teeth lived on after death.
How did tyrannosaurs eat?
🦖 Recently in Montana, USA, scientists found evidence of the Edmontosaurus’s edmontosaurus, whose teeth were shed from its beak.
🦖 In Canada, evidence of tyrannosaur teeth was found together with its own skeleton — with small fragments of dinosaur bones.
💰 Among other dinosaur’s teeth, tyrannosaurs were found to be the most active consumers of kills.