A monstrous oviraptor from the Hell Creek Formation has been discovered in the US. Analysis of the hell chicken’s hindlimb suggests it weighed about 78 kilograms (172 pounds) and is a new-to-science species, indicating that there was a greater diversity of caenagnathid dinosaurs in the Hell Creek ecosystem shortly before the asteroid hit.
The Chicxulub impact crater is the witness mark of one of when an enormous asteroid hit, setting off a chain of events that would eradicate 70 percent of all species on Earth, including the dinosaurs. It’s long been debated whether dinosaurs were doing well, or already on their way out, before the Cretaceous–Paleogene (K–Pg) extinction event, and one way we can study this is by looking at the diversity of animal groups in ecosystems.
One theory suggests that the asteroid acted like the stick that broke the donkey’s back, pushing an already . Evidence for this argument points to the diminishing number of species recorded in the fossil record in the lead-up to the asteroid hit.
However, there are a few reasons why this could be painting the wrong picture. Firstly, this is based on the fossil record that we’ve found, and secondly, it relies on us having accurately identified species from scant remains.
This new species of oviraptor is a testament to that, as it’s described only from a hind limb. However, researchers were able to glean enough information from that one leg to confidently assert that it doesn’t fit within the other known oviraptor species that were living in this region, at the same time.
The new species was named Eoneophron infernalis. Its genus name is derived from the Ancient Greek “eo” for “dawn,” and the genus name of the Egyptian vulture, Neophron, which is known as the “pharoah’s chicken”. The species name is a hat tip to where it was found, being Latin for Hell, and together the words equate to “Pharoah’s dawn chicken from Hell”. Nice.
Features of the femur were unique, and not like the larger oviraptor Anzu wylei’s, making it unlikely it was simply a smaller individual of the larger species (an argument that’s gone back and forth between ). Furthermore, the histological analysis suggested that the animal was either adult or subadult when it died, so combined with the unique proportions and combinations of its features, it looks like we’re dealing with a new kind of hell chicken.
“This smaller caenagnathid from the Hell Creek Formation has implications for the ecology and diversity of caenagnathids in the end-Maastrichtian,” concluded the study authors. “As many as three taxa of varying body size may have inhabited the Maastrichtian ecosystems of the Hell Creek Formation, but like in other regions, a poor fossil record makes untangling the taxonomy of these species problematic.”
“The ecology of caenagnathids likewise remains poorly understood, but E. infernalis expands the range of morphological variation within the family and suggests that caenagnathid diversity in Laurasia remained largely stable through the Campanian-Maastrichtian, and these dinosaurs remained successful components of Laurasian ecosystems until the K-Pg extinction.”
The study is published in .