66 million year old fossils excavated from a North Dakota Ranch in 1999 have been classified as a new species of dinosaur. The dinosaur was identified from the partial remains of three skeletons collected in North and South Dakota, which together make an almost complete skeleton. The dinosaur has officially been named Anzu wyliei, and has been nicknamed the “Chicken from Hell” by scientists. The dinosaur is named after Anzu, a bird demon from Mesopotamian mythology, and wyliei, the grandson of a museum trustee. The nickname incorporates the rock layer in which the fossils were found – the Hell Creek Formation – combined with observations like this one from Emma Schachner, a paleontologist of the University of Utah “It would look like a really absurd, stretched out-chicken.”
These dinosaurs weighed in at 500 pounds, measured 11 feet in length, and stood seven feet tall with their head upright. To put things into perspective, that is 1 inch taller and more than twice as heavy as the largest living dinosaur in today’s world (Jonas Valanciunas of the Toronto Raptors). The dinosaur had a rounded crest on its head and a strong tail. Its jaws were tipped by a toothless beak and it was probably covered in feathers. In addition to its long limbs, the species was found to sport a stubby tail which was likely framed by a fan of tail feathers. There was no direct evidence found that the ancient animal sported feathers, but because of the fact that the species is so closely related to birds, it was likely covered in feathers similar to those we see today on modern birds. The reason that they were feathered is not completely understood, as its environment was hot so they were not needed for insulation. Some scientists believe that using the aesthetic appeal of feathers for courtship could give reason for this flightless bird relative to sport this feature.
The Anzu bones are the first indication that Oviraptorosaurs also lived in North America in addition to Central and East Asia where most evidence of their existence comes from.
The Chicken from Hell is among the largest feathered dinosaurs found in North America, and is the largest member of the Oviraptorosaurs family of dinosaurs. Oviraptorosaurs literally translates to “egg thief lizards.” This reputation arose when the first fossil of that kind was found on top of a nest of eggs, and paleontologists assumed it was eating them. The same type of fossil was later found in scenarios that suggested that their presence in the nests was in a parental role. It is still believed, however, that based on the shape of the dinosaur’s jaws, eggs comprised a part of Anzu’s diet, but not the whole thing because dinosaurs only laid eggs at certain times. The dinosaur’s jaw shape also suggests it could shear off pieces of plants, and its large curved claws are usually found on animals that grab small prey. Such flexibility in diet could explain why the Oviraptorosaurs were so diverse and successful a species in their time.
These discoveries are important because the Hell Creek site was formed in the last two million years of the cretaceous period, right before dinosaurs were wiped out. These discoveries dispute the arguments made by some researchers who believe that dinosaurs were already on the decline at this point due to climate change. Hans Sues on the Smithsonian Institute states that the discovery of Anzu further proves the idea that species were still evolving in diverse, flourishing communities during this period. “This is consistent with the idea that a mass extinction was caused by the great asteroid impact 66 million years ago. It’s clear that dinosaurs were still quite diverse until the very end,” says Dr. Sues.
The Hell Creek Formation is one of the most picked-over areas of the world for dinosaur fossils; Mathew Lamanna of the Carnegie Museum of Natural History commented on the discovery by saying, “The fact that this big, distinctive, very weird-looking animal remained effectively hidden in one of the best-explored set of rocks shows you how much more out there is left to be found.”
The three Anzu skeletons currently reside at the Carnegie Museum of Natural History in Pittsburgh, which collaborated with the Smithsonian to identify the new species.
Leave a Reply