Apatoraptor pennatus: a new Caenagnathid Oviraptorosaur From Cretaceous Canada

A new caenagnathid (Dinosauria: Oviraptorosauria) from the Horseshoe Canyon Formation of Alberta, Canada, and a reevaluation of the relationships of Caenagnathidae

Authors:

Funston et al

Abstract:

Our understanding of caenagnathids has benefited from recent discoveries, including nearly complete skeletons from the Hell Creek Formation of Montana. However, their phylogenetic relationships remain unclear. A new specimen from the Horseshoe Canyon Formation of Alberta has implications for the phylogeny and paleobiology of these creatures. The partial skeleton is articulated and includes a mandible, a full cervical and dorsal series of vertebrae, a right pectoral girdle and arm, a sternum, gastralia, a partial ilium, and a partial hind limb. The mandible is edentulous and the articular ridge is intermediate in form between Caenagnathus collinsi and Chirostenotes pergracilis. The neck is long and composed of at least 11 well-pneumatized cervical vertebrae with fused cervical ribs. The dorsal ribs have finger-like uncinate processes dissimilar in shape to those of other oviraptorosaurs. The pectoral girdle is large and typically maniraptoran, except that the glenoid of the scapulocoracoid faces laterally instead of posteroventrally. The arm is well muscled and can be interpreted to have been a pennibrachium, as indicated by ulnar papillae on the ulna. The manus is characterized by a short first metacarpal but an elongate phalanx I-1 and oviraptorid-like phalangeal proportions in the second digit. These and other features indicate that the specimen represents a new taxon, Apatoraptor pennatus, gen. et sp. nov. Phylogenetic analysis resolves the complicated relationships of Caenagnathidae and allows the evolution of display features to be traced throughout Oviraptorosauria.

Large Caenagnathid Oviraptorosaur From Campanian/Maastrichtian Cretaceous

Large caenagnathids (Dinosauria, Oviraptorosauria) from the uppermost Cretaceous of western Canada

Authors:

Bell et al

Abstract:

Large caenagnathid unguals are described from the Dinosaur Park (upper Campanian) and Frenchman (Maastrichtian) formations of Alberta and Saskatchewan, respectively. The latter constitutes the first formal description of Caenagnathidae from the Frenchman Formation. The Saskatchewan material is also notable for its large size, comparable to Anzu wyliei from the coeval Hell Creek Formation, placing them among the largest caenagnathids from North America. The slightly smaller Dinosaur Park unguals may pertain to either Caenagnathus collinsi (a taxon for which manual material is only tentatively known) or to an as yet unidentified large taxon. The new material demonstrates that despite an apparent reduction in diversity in the Maastrichtian, North American caenagnathid distribution did not retract notably from its Campanian maximum.

Anzu wyliei: a Feathered Caenagnathidae Oviraptorosaur (Hell Chicken) From Maastrichtian Cretaceous Hell Creek

A team of researchers has announced the discovery of a bizarre, bird-like dinosaur, named Anzu wyliei, that provides paleontologists with their first good look at a dinosaur group that has been shrouded in mystery for almost a century. Anzu was described from three specimens that collectively preserve almost the entire skeleton, giving scientists a remarkable opportunity to study the anatomy and evolutionary relationships of Caenagnathidae (pronounced SEE-nuh-NAY-thih-DAY)—the long-mysterious group of theropod dinosaurs to which Anzu belongs. The scientific paper describing the discovery appears today in the well-known and freely-accessible journal PLOS ONE.

The three described fossil skeletons of Anzu were unearthed in North and South Dakota, from roughly 66 million-year-old rocks of the Hell Creek Formation, a rock unit celebrated for its abundant fossils of famous dinosaurs such as Tyrannosaurus rex and Triceratops.

The team of scientists who studied Anzu was led by Dr. Matthew Lamanna of Carnegie Museum of Natural History in Pittsburgh. Dr. Lamanna's collaborators include Dr. Hans-Dieter Sues and Dr. Tyler Lyson of the Smithsonian Institution's National Museum of Natural History in Washington, DC, and Dr. Emma Schachner of the University of Utah in Salt Lake City. According to Dr. Lamanna, "Anzu is far and away the most complete caenagnathid that has ever been discovered. After nearly a century of searching, we paleontologists finally have the fossils to show what these creatures looked like from virtually head to toe. And in almost every way, they're even weirder than we imagined."

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