There were cannibal dinosaurs. This is the conclusion that a new study published in the journal PLOS ONE raises about the fossil remains discovered in a large quarry in Colorado.
In this work, a team of researchers from the University of Tennessee, Knoxville, examined dinosaur bones from the Mygatt-Moore quarry near the Utah-Colorado border that date to the late Jurassic period about 150 million ago. years, paying special attention to the bite marks present in the fossils. Many bones bore the characteristic bite marks of theropod dinosaurs (a large group of bipedal carnivores like avian dinosaurs, including Tyrannosaurus rex and velociraptors). These types of markings are quite rare , as carnivores generally target softer tissues, but in this quarry, nearly 29% of the 2,368 bones examined had notches from theropod teeth.
And, in some cases, both the biter and the victim were of the same gender, providing “extremely rare” fossil evidence of cannibalism among dinosaurs.
According to experts, in the face of food shortages, the hungry dinosaurs would have done everything possible to eat, although that means even eating one of their own.
This is a rare glimpse into the feeding habits of Jurassic carnivores, an anomaly as it reveals fossils with an unusually high density of cuts and impressions clearly made by theropod teeth.
Examining the damage left by the jagged edges of the dinosaurs’ teeth, the authors infer that most of these bites were likely made by the large predator Allosaurus , the most common theropod found in the quarry. While most of the notches were found in herbivorous dinosaur bones, about 17% were bites that theropods had made on the bones of other theropods, and about half of these notches were found in lesser body parts. nutritious, suggesting the action of scavengers that arrived after the best pieces had decomposed or had been eaten by other carnivores.
” Large theropods like Allosaurus probably weren’t particularly fussy , especially if their environment was already limited by resources,” says Stephanie Drumheller, lead author of the study. “Cannibalism was definitely on the table.”
The study is a fascinating example of how forensic dinosaur dentistry can be used to gather evidence about the behavior of dinosaurs, something that paleontologists rarely have the opportunity to study in such depth.
It’s clear that at some point, what was a lushly vegetated home for many large dinosaur species, including the long-necked Apatosaurus and the bipedal carnivore Allosaurus , went through tough times, forcing local carnivores to forage for meat. in any way possible.
But Allosaurus is not the only dinosaur accused of cannibalism . The “very deep grooves” previously found in the bones of Tyrannosaurus rex from the Lance Formation, Wyoming, suggest that one of their own gnawed at its dead body.
Referencia: Drumheller SK, McHugh JB, Kane M, Riedel A, D’Amore DC (2020) High frequencies of theropod bite marks provide evidence for feeding, scavenging, and possible cannibalism in a stressed Late Jurassic ecosystem. PLoS ONE 15(5): e0233115. doi.org/10.1371/journal.pone.0233115
