Thursday, 20 March 2014

Deja vu: "Chicken from Hell"

I don't know who coined this fossil "Chicken from Hell", but I am sure the media had to invent an "attractive" title for the dinosaur discovery, to make it stand out from the rest of the gloomy news from the World and yet fit into the mood. Since the fossil in question is from the famous Hell Creek formation and looks a lot like a mutant chicken, armed with the nasty hand claws, the title is quite appropriate. The only thing about the "news" is that it is not so new.
In fact, the CNHM paleontologist Matt Lamanna and the other authors have finally  published a paper that presents the first decent look into the complete morphology of caenagnathids.
Anzu wyliei was a peculiar looking, bird-like dinosaur that had a bony crest on top of a beaky head and relatively short tail for a theropod.
The animal has been identified from the partial remains of three skeletons collected in North and South Dakota that have been known for a while. In fact, my restoration of this caenagnathid in the image below is about 10 or more years old.
When all fossils are combined, about 80% of the skeleton is now known. Which is incredibly complete by the paleontologists standards. The animal lived some 66 million years ago in the biota where Tyrannosaurus rex was the top predator. Being 5ft high at the hips (150 cm), the giant "chicken" presented a danger for the smaller dinosaurs and other tetrapods of the time.
All three Anzu skeletons are housed at the Carnegie Museum of Natural History in Pittsburgh, which collaborated with the Smithsonian to identify the new species.
Here is the free paper:
 Matthew C. Lamanna, Hans-Dieter Sues, Emma R. Schachner & Tyler R. Lyson (2014) A New Large-Bodied Oviraptorosaurian Theropod Dinosaur from the Latest Cretaceous
of Western North America. PLoS ONE 9(3): e92022. doi:10.1371/journal.pone.0092022

  Abstract: The oviraptorosaurian theropod dinosaur clade Caenagnathidae has long been enigmatic due to the incomplete nature of nearly all described fossils. Here we describe Anzu wyliei gen. et sp. nov., a new taxon of large-bodied caenagnathid based primarily on three well-preserved partial skeletons. The specimens were recovered from the uppermost Cretaceous (upper Maastrichtian) Hell Creek Formation of North and South Dakota, and are therefore among the stratigraphically youngest known oviraptorosaurian remains. Collectively, the fossils include elements from most regions of the skeleton, providing a wealth of information on the osteology and evolutionary relationships of Caenagnathidae. Phylogenetic analysis reaffirms caenagnathid monophyly, and indicates that Anzu is most closely related to Caenagnathus collinsi, a taxon that is definitively known only from a mandible from the Campanian Dinosaur Park Formation of Alberta. The problematic oviraptorosaurs Microvenator and Gigantoraptor are recovered as basal caenagnathids, as has previously been suggested. Anzu and other caenagnathids may have favored well-watered floodplain settings over channel margins, and were probably ecological generalists that fed upon vegetation, small animals, and perhaps eggs.

My old restoration of the caenagnathid (Krzic 2002?)

Another link to the news.

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