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Cope, E. D., 1870.

Additional note on Elasmosaurus.

American Journal of Science, Series 2, 50(149):268-269.

Copyright © 2002-2009 by Mike Everhart

Created 01/12/2002; updated 05/21/2011



LEFT: Drawing of Elasmosaurus platyurus Cope by Adam Stewart-Smith. Copyright © 2003 by Adam Stewart-Smith. Used with permission.


268                            Scientific Intelligence


   4. Additional note on Elasmosaurus; by E. D. Cope. - To my preceding note on Elasmosaurus, I append the following, in consequence of the reading of another criticism by Prof. Leidy, in the Proceedings Acad, Nat. Sci, Philad., January to April, 1870, (issued in June). [Leidy, J., 1870. Discosaurus and its allies. Proc. Acad. Nat. Sci. Phil. 22:18-22. (April 5, 1870)- Ed.]

   In this Dr. Leidy agrees with my identification of Cimoliasaurus and Discosaurus made in 1868, regarding them as the same. But he employs the name Discosaurus instead of Cimoliasaurus, to which we object for three reasons: 1, in works written subsequent to his determination, Cimoliasaurus had been exclusively used, and has therefore obtained considerable currency; 2, Discosaurus was founded upon a miscellaneous collection of species, and not defined; 3, the name refers perhaps to an individual peculiarity of one of the species, as suggested by Leidy, and conveys an erroneous impression of there being a vertebral disc characteristic of the genus, whereas the peculiarity consists of a groove. The name Cimoliasaurus is open to none of these objections.

   He however unites with the above genus my Elasmosaurus, although a few pages previously he considers them distinct, on the same grounds that convinced me of the propriety of separating them, viz.: the enormous neck with compressed vertebrę III the one, and the short transverse cervicals of the other. No such difference is displayed by the species of Plesiosaurus, though there is considerable variation in the genus in this respect. It cannot however be predicted, that no species combining the characters of the two will ever be found. All genera in paleontology stand open to this risk,

     The Cimoliasaurus grandis (Brimosaurus Leidy) presents the shortened cervicals of C. magnus and therefore is not an


                                      Geology and Mineralogy.                     269


Elasmosaurus. The E. orientalis is as yet but little known, and there way be doubts as to which genus it represents. In a restored figure of it which was given in an article in the American Naturalist 1868, p. 84), it is represented with a neck of the shorter type of Cimoliasaurus. Whether the shorter or longer type of cervicals belong to it will remain uncertain until more remains are found.    If it be a true Elasmosaurus, the figure will represent better a Cimoliasaurus.

   In his second notice Leidy mentions his having reversed the extremities of the vertebral series in the three Cimoliasauri described by him.