Fruit-munching dinosaurs once roamed Montana, as researchers revealed in findings published on October 10 in Nature Communications.
More than 65 million years ago, a small, beaked dinosaur dubbed the “hell chicken” operated as a real terror to fruit. Reconstruction of its beak and jaw suggest it mashed up fruit much like modern parrots.
Science News reported that this is the first evidence of non-avian dinosaurs evolving specialized adaptations for eating fruit, occurring as flowering plants emerged. An unusual theropod dinosaur’s fossilized skeletal remains were largely uncovered in eastern Montana in 2011 by a fossil collector, who then shared the find with Royal Ontario Museum paleontologist David Evans in Canada.
Subsequent excavations across Montana alongside North and South Dakota by paleontologists and fossil hunters over the following several years brought four additional partial skeletons to light. Oviraptorosaurs—a distinctively avian-like classification of beaked theropods from the Cretaceous Period—included this particular dinosaur.
- Dietary Specialization: This specific theropod adapted its jaw mechanics specifically to process fibrous plant material and fruit flesh rather than consuming purely carnivorous diets.
- Kinematic Evolution: Its unique skull architecture allowed a sliding, back-and-forth jaw motion reminiscent of modern psittacines, or parrots.
- Ecological Shifts: The emergence of angiosperms (flowering and fruiting plants) during the Cretaceous Period directly drove new evolutionary feeding niches among prehistoric fauna.
This species probably weighed around 12 kilograms, making it about the size of a turkey. Following its unearthing in the Hell Creek geological formation and noting its general resemblance to poultry, researchers including Evans and Stony Brook University paleontologist Greg Funston in New York designated the creature Infernogallus jamesi, commonly known as the “hell chicken.”
Upon analyzing the skull of Infernogallus and mapping its muscle structure, the team realized this animal was far from a typical theropod. Unlike their biting and chomping kin, its palate, muscles, and jaw joints were built to shift the jaw backward and forward during feeding rather than operating in an up-and-down motion.
This chewing style remains unique among non-avian dinosaurs but is strikingly similar to that of fruit-eating parrots. Utilizing its tongue together with sliding jaw movements, Infernogallus was likely equipped to skillfully strip flesh away from large seeds as part of a diet heavily reliant on fruit, according to Funston and fellow researchers.
“But the more we delved into it, the more sense it made,” Funston says. “All the different lines of evidence seemed to converge on this one answer.”
Angiosperms—plants that produce flowers and fruits—were rapidly diversifying throughout the Cretaceous. Growing data points toward a coevolutionary relationship between Cretaceous animals and angiosperms, indicating dinosaurs might have consumed their fruits.
Infernogallus contributes new insight to this developing scenario. Funston notes that additional dinosaur lineages or close relatives of the “hell chicken” may have similarly relied on fruit as a regular part of their diets.
“[The discovery] suggests that our picture of dinosaur ecology right before the Cretaceous extinction has been missing major puzzle pieces, and that dinosaurs were more diverse than we thought,” Funston said.
- Nature Communications.
- Royal Ontario Museum. Fossil discoveries in the Hell Creek Formation.
