A nearly complete skull of a Late Cretaceous dinosaur suggests the animal could chew soft plants, giving researchers evidence that some non-avian dinosaurs may have specialized in fruit.
The study, published Oct. 10 in Nature Communications, names the species Infernogallus jamesi, a caenagnathid oviraptorosaur. Its fossil preserves nearly the whole skull assembled, the first known from this lineage. The Royal Ontario Museum estimates that it weighed about 12 kilograms (25 pounds) and describes it as turkey-sized.
CT scans showed that bones in the palate curved downward, aligning some chewing muscles from front to back instead of vertically. The researchers say this arrangement could have allowed the lower jaw to slide forward and back. Ridges and grooves along opposing jaw surfaces may have met during that motion, helping the animal handle soft food. The study says this muscle arrangement is unusual among non-avian theropods and resembles features found in fruit-eating parrots.
From those features, the authors infer that fleshy fruits from flowering plants likely made up a large share of the diet. The fossil does not record the animal’s meals directly, and the study does not establish that fruit was its only food.
The paper says the relationship between herbivorous dinosaurs and flowering plants remains debated. It presents caenagnathids as among the strongest candidates for adaptations to a flowering-plant diet, based on skull anatomy. The authors also connect the group’s changing chewing traits with the increasing size and variety of fleshy fruits, but say the evidence does not establish whether caenagnathids helped spread them.
Greg Funston, an assistant professor in Stony Brook University’s Department of Anatomical Sciences, said the result surprised researchers. “We never expected to discover fruit-eating dinosaurs,” he said.
The fossils came from the Hell Creek Formation. The Royal Ontario Museum says Infernogallus lived alongside T. rex and Triceratops.
