Anzu wyliei is a recently discovered species of feathered theropod oviraptorosaur from the late Cretaceous (66-68 million years ago). The "chicken from hell," as it was nicknamed to its fierce features and discovery location, is known from four specimens which were excavated from the Hell Creek Formation in North and South Dakota between 1998-2006. Together these well-preserved specimen comprise about 80% of an entire skeleton, giving an important contribution to the understanding of this poorly-understood lineage. The formal name, description and analysis are now published (Lamanna et al. 2014). The authors named the fossil for Anzu, a feathered demon of Mesopotamian mythology.
The largest oviraptor known from North America, A. wyliei was 1.5 meters (4.9 feet) tall, 3 meters (9.8 feet) long, and estimated at 200-300 kg (440-660 pounds). It had a large, but delicate, crest on its head, postulated to be involved in displaying to females and/or males of its species, and sharp claws. Analysis of the fossils indicate that A. wyliei was a generalist omnivore, eating plants, small animals and eggs and probably not spending much time in trees, as previous fossil findings of North American oviraptors might imply. Unlike the generally smaller Asian oviraptors, which preferred arid environments, the discovery of A. wyliei remains in fluvial mudstones of what was at the time of its existence a warm swamp, suggest that Caengnathidae inhabited wetter environments, perhaps floodplains.
Oviraptors were bird-like dinosaurs that ranged from species the size of a chicken to enormous species in excess of a metric ton. Most are known from Asia (principally China and Mongolia). Oviraptors have been known from North America for a hundred years, but only from a very few, incomplete, skeletal fragments. The discovery and account of A. wyliei brings together many aspects of the poorly-understood North American Oviraptorosaurs, resolving controversy regarding whether these species made up a true lineage distinct from the Asian oviraptorosaurs. Not only did the discovery of A. wyliei confirm the North American oviraptors as a monophyletic group (known as the Caenagnathidae) with a significantly different body structure, these fossils contribute a huge jump in the understanding of the ecology and evolution of the North American lineage.
(Lamanna et al 2014; Fawcett 2014; Sues 2014)
