copevrt2.jpg (26988 bytes)

[On the structure of the vertebral column in Elasmosaurus].

Proceedings of the Academy of Natural Sciences of Philadelphia, 20:181. (for the meeting of July 14, 1868)

Copyright © 2002-2009 by Mike Everhart - ePage created 02/13/2002; updated 01/07/2013

This is a recap of the paper wherein E. D. Cope presented information regarding the discovery of a new kind of plesiosaur (Elasmosaurus platyurus) at the Academy of Natural Sciences of Philadelphia meeting of March 24, 1868.

180                      PROCEEDINGS OF THE ACADEMY OF

                                                July 14th.

                        The President, Dr. Hays, in the Chair.

      Nineteen members present.

      The following papers were presented for publication:
       "Second contribution to the history of the Vertebrata of the Miocene period of the United States." By Edw. D. Cope.
      "Remarks on Conosaurus," By Joseph Leidy, M.D.
      "Remarks on a jaw fragment of Megalosaurus." Jos. Leidy, M.D.


                                  NATURAL SCIENCES OF PHILADELPHIA                            181

    E. D. Cope exhibited the vertebra of an extinct reptile, from the middle green sand bed of New Jersey; which possessed the peculiar articular structure known as zygantrum and zygosphen. He said the form was in some degree like that of certain terrestrial genera of Iguanidę, as the genus Euphryne, Baird, but it appeared to have some affinity to Macrosaurus, Owen, in form. The animals if similar in proportions to the Iguanę, would have been some 12 feet in length. It was called Clidastes iguanavus.

    A Mosasauroid reptile was indicated by a single vertebra from Medford,
N.J., also from the middle bed. It was distinguished from other forms of
the family by its compressed elevated form. It was assigned to a species
named Nectoportheus validus.

    The structure of the vertebral column in Elasmosaurus was pointed out.
It was stated to possess apparently no zygapophyses throughout its whole
length, but in place of these, the zygosphen and zygantrum articulation. 
The articulations of the vertebrę were therefore the reverse in respect to
direction of their surfaces from the usual form among vertebrata. In fact,
the structure of the genus was shown to be entirely new and peculiar among
vertebrated animals. The genus Cimoliasaurus Leidy, was stated to exhibit
the same structure, and required that the vertebrae should be reversed in
order to read their connections correctly.