Turkey-Sized Feathered Dinosaur Ate Fruit
Infernogallus jamesi, a turkey-sized feathered dinosaur weighing roughly 12 kilograms, lived alongside Tyrannosaurus rex and Triceratops during the Cretaceous period and featured a specialized frugivorous diet. ScienceAlert reported that the newly described species, commonly known as the hell chicken, represents one of the first known fruit-eating dinosaurs in the fossil record.
Thomas Dudgeon, an evolutionary biologist at the Royal Ontario Museum in Canada, noted the distinct nature of the find. “It’s pretty rare for animals to become specialized for a diet of fruit, so when it comes, it comes with some remarkable adaptations,” Dudgeon stated. “The anatomy of Infernogallus is bizarre among dinosaurs, and we quickly realized that we were dealing with something special.”
Toothless Beak Operated in Front-To-Back Direction
Researchers examined five specimens, focusing in particular on a nearly complete skull with connected bones alongside a partial skeleton. DiscoverMagazine noted that small dinosaur remains of this completeness are uncommon in the fossil record. CT scans of the hell chicken revealed a curved, toothless beak similar to a modern-day parrot or turtle. However, the bite force was too weak to crack tough nuts, seeds, or shells, and the specimen lacked the teeth necessary to grind fibrous ferns or gizzard stones in the gut.
Instead, the muscular arrangement in the jaw operated in a front-to-back direction rather than up-and-down. The dinosaur’s palate featured a pair of bony surfaces packed with a complex pattern of ridges and grooves. During this anteroposterior movement of the mandible, the upper and lower jaws met to shear and crush soft foods, functioning similarly to a mortar and pestle.
Lineage Adapted for Feeding on Fruit Flesh
The researchers traced the origin of caenagnathids—the family containing Infernogallus—back to between 107 and 118 million years ago, a timeline overlapping with the appearance of early drupes. By the time Infernogallus emerged around 68 to 66 million years ago, the lineage had fully adapted for feeding on fruit flesh like peaches and cherries.
Gregory Funston, lead researcher on the study published in Nature Communications, highlighted the unexpected nature of the discovery. “We knew dinosaurs evolved to fill so many different roles in ecosystems in the Cretaceous, but we never expected to discover fruit-eating dinosaurs,” Funston said. “For more than 100 years, we didn’t know what the skulls of these animals looked like. Now, we know they were even weirder than we could have predicted.”
End-of-Cretaceous Survival Pressures
David Evans, chief curator at the Royal Ontario Museum, emphasized the rarity of the find. “Complete remains of small dinosaurs like Infernogallus are very rare in the fossil record,” Evans explained. “The strange skull of Infernogallus is an exciting find because it reveals surprising insights into dinosaur evolution and feeding specialization.”
Despite possessing traits normally associated with surviving the asteroid impact—such as small body size, a probable avian-like metabolism, and a herbivorous diet—the hell chicken’s dietary specialization may have contributed to its extinction.
