The "Hell Chicken" That May Have Been the First Fruit-Eating Dinosaur

The "Hell Chicken" That May Have Been the First Fruit-Eating Dinosaur

Among the giant predators and lumbering plant-eaters of the Late Cretaceous, a small dinosaur was evolving a very different diet. A new species described in Nature Communications in October 2026, Infernogallus jamesi, appears to be the first known dinosaur that specifically ate fruit.

Infernogallus means "hell chicken". The name comes from the Hell Creek Formation in the United States — stretching across Montana, North Dakota, South Dakota and Wyoming — where its fossils were found, and where it lived alongside T. rex and Triceratops. The fossil, a nearly complete, articulated skull with part of the skeleton, is now on display at the Royal Ontario Museum in Toronto.

A turkey-sized dinosaur with a parrot's jaw

Infernogallus belonged to the caenagnathids, a group of toothless, feathered dinosaurs. It was about the size of a turkey and weighed about 12 kg (25 lbs), making it one of the smallest members of its group even as a fully grown adult. Curiously, Infernogallus and its relatives evolved from the meat-eating side of the dinosaur family tree.

The clue to its diet is in the roof of its mouth. Led by Dr Gregory Funston, assistant professor in the Department of Anatomical Sciences at Stony Brook University, researchers from Stony Brook, the Royal Ontario Museum and the North Dakota Geological Survey used CT scans to reconstruct the skull and its chewing muscles.

They found that the palatal bones — the bones forming the roof of the mouth — arched downwards into the mouth itself. That turned certain chewing muscles to face front-to-back instead of up-and-down. The lower jaw could slide forward and backward by up to about 15 mm, and the ridges and grooves inside the mouth may have acted like a mortar and pestle. Instead of a strong up-and-down bite, the animal mashed soft food with a sliding, chewing motion, more like a human chewing than like the rigid bite of T. rex.

That arrangement is rare in the animal kingdom. Among living animals, the closest match is found in some fruit-eating parrots, such as Pesquet's parrot, which mash fruit pulp and discard the seeds. The researchers conclude that Infernogallus was probably specialised for processing soft, fleshy fruit in the same way — mashing stone fruits to remove the flesh from the seed. Detailed analysis of its chewing mechanics supports that reading, and the team describes it as the first known dinosaur specifically adapted to eat fruit.

What remains unknown

The researchers are careful about how far the evidence goes. Whether these dinosaurs actively helped spread plant seeds, and so helped drive the spread of fruiting plants, is still an open question. Their paper notes that the dinosaurs' role in the Late Cretaceous proliferation of fruit — which shaped the plant life of the early Cenozoic era that followed — "remains unclear".

Infernogallus lived near the end of the Cretaceous, roughly 68 to 66 million years ago, soon after fleshy fruits first became common. Its story is a reminder that evolution does not only produce bigger teeth and longer necks: sometimes the most remarkable adaptation is a jaw that learned to chew.

If your child is fascinated by dinosaurs, fossils, or how scientists read a diet from the shape of a skull, a first lesson in biology can take them from food chains and adaptation to the evidence palaeontologists actually use. Book your first lesson

Sources:

• Funston, G. F. et al., "Fruit-eating adaptations in a Late Cretaceous oviraptorosaur (Theropoda)", Nature Communications (2026), published 10 October 2026. DOI: 10.1038/s41467-026-78343-w
• Royal Ontario Museum, "Rare fossil discovery reveals new dinosaur species that were specialized fruit-eaters", 28 October 2026: https://www.rom.on.ca/news-releases/rare-fossil-discovery-reveals-new-dinosaur-species-were-specialized-fruit-eaters
• Stony Brook University, "Stony Brook Dinosaur Discovery Reveals a Specialized Fruit Eater": https://news.stonybrook.edu/university/stony-brook-paleontologist-dinosaur-discovery-reveals-a-specialized-fruit-eater/

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