'Chicken From Hell': Bones of Newly Identified Dinosaur Species Discovered in South Dakota

Paleontologists have discovered a new species of dinosaur, nicknamed “Chicken from Hell,” offering new insight into the state of the dinosaur population before they went extinct.

Knewz.com has learned that scientists are divided about whether the population of dinosaurs had already been dwindling before the fateful asteroid wiped them from the face of the Earth.

Artist’s rendition of the Caenagnathid dinosaurs from the final 2 million years of the Cretaceous period discovered by paleontologists. By: Kyle Atkins-Weltman, Eric Snively, et al.

Paleontologists now believe that the discovery of the new species can help offer more information in this regard.

Much like the discovery of the Tyrannosaurus mcraeensis, a newly discovered relative of the apex predator T. rex, the fossil of the “Chicken from Hell” was also originally wrongfully labeled as the juvenile specimen of an already discovered species.

Unearthed in South Dakota, in rocks of the Hell Creek Formation, and dating back to the final 2 million years of the Cretaceous period, the specimen was believed to be a juvenile Anzu, the only known species of caenagnathid from this time and region.

Caenagnathids are a classification of dinosaurs with birdlike features like toothless beaks, long legs and short tails. The Anzu species are believed to be omnivorous dinosaurs, weighing roughly between 450 and 750 pounds.

Paleontologists studied the four hindlimb bones of the mislabeled Caenagnathid specimen. By: Kyle Atkins-Weltman, Eric Snively, et al.

However, after studying four hindlimb bones, a femur, a tibia and two metatarsals, of the discovered smaller specimen, paleontologists finally recognized it to be an adult specimen of an entirely new species of the Caenagnathid group.

Paleontologists reached this conclusion after conducting a detailed study of the bone rings of this newly discovered dinosaur.

“Just like with a tree’s rings, bone records rings called lines of arrested growth. Each annual line represents part of a year when the animal’s growth slowed. They would tell us how old this animal was, and how fast or slow it was growing,” Paleontologists Kyle Atkins-Weltman and Eric Snively wrote in the academic journal The Conversation.

Bone rings of the Eoneophron infernalis. By: Kyle Atkins-Weltman, Eric Snively, et al.

“In a juvenile, we would expect lines of arrested growth in the bone to be widely spaced, indicating rapid growth, with even spacing between the lines from the inside to the outside surface of the bone. Here, we saw that the later lines were spaced progressively closer together, indicating that this animal’s growth had slowed and it was nearly at its adult size,” the scientists further explained.

The new species has been named Eoneophron infernalis, which means “Pharaoh’s dawn chicken from Hell,” referencing the nickname of its larger cousin Anzu.

“Traits unique to this species include ankle bones fused to the tibia, and a well-developed ridge on one of its foot bones. These weren’t features a young Anzu would outgrow, but rather unique aspects of the smaller Eoneophron,” Atkins-Weltman and Snively further wrote.

The latest discovery led paleontologists to further examine other fossils of the period that were previously believed to be the Anzu, and sure enough, they discovered a third similar yet new species of “Hell Chicken.”

The discovery of such diversity in dinosaurs from the final period of their existence on our planet seems to challenge the notion that dinosaurs had already been thinning out before their fated mass extinction. By: MEGA

“Where once there was one ‘chicken from Hell,’ now there were two, and evidence for a third: one large (Anzu), weighing as much as a grizzly bear, one medium (Eoneophron), humanlike in weight, and one small and yet unnamed, close in size to a German shepherd,” the scientists wrote.

The discovery of such diversity in dinosaurs from the final period of their existence on our planet seems to challenge the notion that dinosaurs had already been thinning out before their fated mass extinction.

“Our new discovery suggests that this dinosaur group was not declining in diversity at the very end of the Cretaceous. These fossils show that there are still new species to be discovered, and support the idea that at least part of the pattern of decreasing diversity is the result of sampling and preservation biases,” the scientists wrote in The Conversation.