The discovery of tooth-marked bones belonging to gigantic herbivorous dinosaurs has shed new light on the feeding behaviors of large carnivorous predators inhabiting North America roughly 150 million years a field described as “neglected” by one expert in an interview with Newsweek.
A recent study published in PeerJ Life & Environment delved into the analysis of bite marks on the bones of massive sauropod dinosaurs, like Diplodocus and Brontosaurus, which were made by carnivorous theropod dinosaurs. Sauropods, among the largest terrestrial creatures to have ever roamed the planet, are recognized by their lengthy necks, tails, small heads, and sturdy legs.
On the other hand, theropods encompass a diverse group of primarily carnivorous, bipedal dinosaurs. Birds, the descendants of a lineage of small theropods, also fall within this category. Bite marks on bones serve as valuable evidence of the dietary preferences and behaviors of long-extinct carnivorous animals. While most documented bite marks in dinosaurs have been linked to large Tyrannosaurs, a family of carnivorous theropods prevalent in North American fossil records, the latest research aimed to explore bite traces made by other formidable, non-Tyrannosaur carnivores.
David Hone, a study author from Queen Mary University of London, emphasized the lack of attention given to these earlier carnivorous dinosaurs and their interactions with large sauropods. The study, conducted through an exhaustive review of scientific literature and fossil collections in the Morrison geological formation of the western United States, unearthed numerous sauropod bones displaying bite traces from non-Tyrannosaur, carnivorous theropods.
The Morrison Formation, dating back roughly 150 million years to the Upper Jurassic Period, spans a vast area from Montana to New Mexico and harbors a rich collection of dinosaur fossils. While no Tyrannosaurs are documented in the Morrison Formation time when they were relatively smaller non-Tyrannosaur theropods left a significant mark, with 68 sauropod bones showcasing evidence of their feeding activities.
The researchers noted that the bite traces observed lacked signs of healing, indicating predatory or scavenging activities post-death. Tooth wear analysis further suggested a more frequent bone-biting behavior among non-Tyrannosaur theropods akin to that of their larger Tyrannosaur counterparts. The prevalence of bite traces without healing indications, in addition to tooth wear patterns, hints at these theropods primarily preying on juvenile sauropods and scavenging adult carcasses.
The findings offer insights into the ecological dynamics between large carnivores and giant herbivorous dinosaurs during the Jurassic era, enhancing our understanding of the ancient behaviors of these prehistoric creatures.