A NEW PLESIOSAUR 

 By FREDERIC A. LUCAS 



Among the specimens included in the Marsh collection was a 

 fine example of a plesiosaur which has recently been described by 

 Dr. S. W. Williston^ under the name of Brachanchenias lucasi. 

 Tlie specimen, which lies on its back, comprises the skull and jaws, 

 with thirty-five consecutive vertebrae (plate xxviii). The upper por- 

 tions of the skull and vertebrae were unfortunately weathered away 

 before the discovery of the animal, which was found near Delphos, 

 Ottawa county, Kansas. While the popular idea of a plesiosaur, 

 derived from the graphic descriptions of English writers, is that of a 

 reptile with a long, snake-like neck, yet many short-necked animals 

 are included under that term. The present individual enjoys the 

 distinction of being the shortest necked species yet discovered, and 

 this, coupled with the massive head, causes the specimen to suggest 

 a crocodile, the more that the large swimming paddles were unfor- 

 tunately not preserved, having been washed away before the speci- 

 men became entombed in the deposits forming the Fort Benton 

 limestone. Dr. Williston calls attention to the fact that while 

 plesiosaurs are not at all uncommon in the Cretaceous deposits of 

 North America, they are for the most part represented by detached 

 bones, or at the best isolated, if well-preservqd paddles. So while 

 thirty-two species and fifteen genera have been described from the 

 United States, in not a single one has any considerable portion of the 

 skeleton been preserved, aside from those that have been described 

 by Dr. Williston himself, and the skull is known in but three in- 

 stances. As the present example shows the bones of the under 

 side of the skull very clearly it is of special importance. 



^" North American Plesiosaurs," part i; Fic^.d Cohnubian Museum, 

 Publication 73, Geological Series, vol. 11, No. i ; Chicago, April, igo3, p. 57. 



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