''Brachauchenius'' (meaning 'short neck') is an
extinct
Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...
genus of
pliosaurid that lived in North America (United States) and Morocco
during the
Late Cretaceous.
History
![USNM 2361 - Brachauchenius lucasi skull](https://upload.wikimedia.org/wikipedia/commons/9/9e/USNM_2361_-_Brachauchenius_lucasi_skull.png)
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
Colombia (, ; ), officially the Republic of Colombia, is a country in South America with insular regions in North America—near Nicaragua's Caribbean coast—as well as in the Pacific Ocean. The Colombian mainland is bordered by the Car ...
was considered as part of this genus, representing the first re-occurrence of the non-rhomaleosaurid pliosaurs after a Berriasian-Hauterivian hiatus.
[Hampe O. 2005. Considerations on a ''Brachauchenius'' skeleton (Pliosauroidea) from the lower Paja Formation (late Barremian) of Villa de Leyva area (Colombia). ''Fossil Record - Mitteilungen aus dem Museum für Naturkunde in Berlin'' 8 (1): 37-51.] 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 (
type
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) specimen (USNM 4989) was collected by
Charles Hazelius Sternberg
Charles Hazelius Sternberg (June 15, 1850 – July 20, 1943) was an American fossil collector and paleontologist. He was active in both fields from 1876 to 1928, and collected fossils for Edward Drinker Cope and Othniel C. Marsh, and for the ...
from
Ottawa County, Kansas in 1884.
[''Everhart MJ. 2005. Oceans of Kansas - A Natural History of the Western Interior Sea''. Indiana University Press, 320 pp. .][Everhart MJ. 2007. Historical note on the 1884 discovery of ''Brachauchenius lucasi'' (Plesiosauria; Pliosauridae) in Ottawa County, Kansas. ''Transactions of the Kansas Academy of Science'' 110 (3/4): 255-258.] It had a skull length of up to .
[ The species was named by Samuel W. Williston.][Williston SW. 1907. The skull of ''Brachauchenius'', with special observations on the relationships of the plesiosaurs. ''United States National Museum Proceedings'' 32: 477-489. (pls. 34-37)] The individual to which this specimen belongs would have measured long.[ ''Brachauchenius'' represents the last known occurrence of a pliosaur in North America.
A larger specimen (FHSM VP-321 - skull length 170 cm) was collected by ]George Fryer Sternberg
George Fryer Sternberg (1883–1969) was a paleontologist best known for his discovery in Gove County, Kansas of the "fish-within-a-fish" of ''Xiphactinus audax'' with a recently eaten ''Gillicus arcuatus'' within its stomach. Sternberg was bor ...
in 1952 from the Fairport Chalk of Russell County, Kansas, and later described by Carpenter.[Carpenter K. 1996. A Review of short-necked plesiosaurs from the Cretaceous of the western interior, North America. ''Neues Jahbruch für Geol. Palaont. Abh. (Stuttgart)'' 201 (2): 259-287.] Schumacher and Everhart (2005) reported on the age and locality of both Kansas specimens.[Schumacher BA, Everhart MJ. 2005. A stratigraphic and taxonomic review of plesiosaurs from the old “Fort Benton Group” of central Kansas: A new assessment of old records. ''Paludicola'' 5 (2): 33-54.] This specimen is now reassigned to its own genus and species, ''Megacephalosaurus eulerti
''Megacephalosaurus'' (; "great-headed lizard") is an extinct genus of short-necked pliosaur that inhabited the Western Interior Seaway of North America about 94 to 93 million years ago during the Turonian stage of the Late Cretaceous, containin ...
''.
In 2013, Benson ''et al.'' referred a partial cranium from the Chalk Group
The Chalk Group (often just called the Chalk) is the lithostratigraphic unit (a certain number of rock strata) which contains the Upper Cretaceous limestone succession in southern and eastern England. The same or similar rock sequences occur acr ...
of England (previously referred to '' Polyptychodon'') to ''Brachauchenius'' indet.[Benson RBJ, Evans M, Smith AS, Sassoon J, Moore-Faye S, Ketchum HF, Forrest R. 2013. A giant pliosaurid skull from the Late Jurassic of England. PLOS ONE 8(5):e65989 DOI 10.1371/journal.pone.0065989.]
In 2015, a pliosaur mandible from Turonian deposits near Goulmima
Goulmima () is a town in Morocco situated in the province of Errachidia, in the region of Drâa-Tafilalet. An agricultural oasis, it is fed by the Wadi Gheris from the central High Atlas mountains. Like other settlements in Tafilalet, it was bu ...
, Morocco were referred to the species ''Brachauchenius lucasi''
Classification
The cladogram below follows a 2011 analysis by paleontologists Hilary F. Ketchum and Roger B. J. Benson, and reduced to genera only.
See also
* List of plesiosaur genera
* Timeline of plesiosaur research
References
External links
Oceans of Kansas Paleontology
Late Cretaceous plesiosaurs of North America
Fossil taxa described in 1903
Pliosaurids
Turonian genus extinctions
Taxa named by Samuel Wendell Williston
Sauropterygian genera
{{plesiosaur-stub