Brachauchenius


Brachauchenius is an extinct genus of pliosaurid that lived in North America during the Late Cretaceous.

History

The type species, Brachauchenius lucasi, lived in the Western Inland Sea of North America around 100.5-89.3 million years ago, from the Cenomonian to the Turonian of the Cretaceous. An older specimen from the Barremian of Colombia was considered as part of this genus, representing the first re-occurrence of the non-rhomaleosaurid pliosaurs after a Berriasian-Hauterivian hiatus. However, subsequent analysis of this Colombian specimen shows that it was enough distinctive to warrant a new genus and species, named as Stenorhynchosaurus munozi.
The first known specimen was collected by Charles Hazelius Sternberg from Ottawa County, Kansas in 1884. It had a skull length of about 90 cm. The species was named by Samuel W. Williston. Brachauchenius represents the last known occurrence of a pliosaur in North America.
A larger specimen was collected by George Fryer Sternberg in 1952 from the Fairport Chalk of Russell County, Kansas, and later described by Carpenter. Schumacher and Everhart reported on the age and locality of both Kansas specimens. This pliosaur is estimated to have been between 6 and 9 meters in length. This specimen was reassigned to its own genus and species, Megacephalosaurus eulerti.
In 2013, Benson et al. referred a partial cranium from the Chalk Group of England to Brachauchenius indet.

Classification

The cladogram below follows a 2011 analysis by paleontologists Hilary F. Ketchum and Roger B. J. Benson, and reduced to genera only.
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