Hell Chicken Dinosaur Ate Fruit Using Parrot-Like Jaw Motions

According to Science News, a diminutive, beak-equipped dinosaur known as the “hell chicken” wreaked havoc on fruit over 65 million years ago.

Key Clinical Takeaways:

• Fossil evidence reveals the first known non-avian dinosaur adapted for eating fruit.
• The turkey-sized creature used jaw motions strikingly similar to modern parrots.
• The discovery indicates that Cretaceous dinosaur ecology was more diverse than previously understood.

A fossil hunter uncovered a significant portion of an unusual theropod dinosaur’s fossilized skeleton in eastern Montana back in 2011 and alerted David Evans, a paleontologist stationed at the Royal Ontario Museum in Canada. In the subsequent years, researchers and fossil collectors working across Montana alongside North and South Dakota dug up four additional incomplete skeletons.

The dinosaur was part of the oviraptorosaurs, a notably avian-like category of beaked theropods that existed throughout the Cretaceous Period. 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 given its resemblance to a bird, researchers including Evans and Stony Brook University paleontologist Greg Funston in New York designated the creature Infernogallus jamesi, or “hell chicken.” Upon examining the skull of Infernogallus and mapping out its muscle structure, the team realized it was far from a typical theropod.

Analysis of its palate, muscles, and jaw joints reveals that it chewed by sliding its jaw back and forth instead of moving it vertically like its meat-eating peers. Among non-avian dinosaurs, this mastication method stands alone, yet it bears a remarkable resemblance to the technique used by parrots that consume fruit.

Funston and his team propose that Infernogallus evolved to thrive on a diet heavy in fruit, skillfully employing its tongue and sliding jaw mechanics to strip flesh away from large seeds.

“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.”

As flowering and fruit-bearing plants known as angiosperms underwent rapid diversification during the Cretaceous, a study published October 10 in Nature Communications indicates that these plants were coevolving alongside Cretaceous fauna, with dinosaurs potentially consuming their fruits.

Infernogallus adds to that emerging picture. It is possible that other “hell chicken” relatives or other dinosaur groups were habitual fruit eaters too, Funston says.

“[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 says.