Description of Tertiary Artiodactyles / by O.C. Marsh.

  • Marsh, Othniel Charles, 1831-1899.
Date:
1894
Catalogue details

Licence: Public Domain Mark

Credit: Description of Tertiary Artiodactyles / by O.C. Marsh. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

    3/18
    Rom the American Journal of Science, Yol. XLYIII, Sept., 1894.] DESCRIPTION OF TERTIARY AR&IQDACTYLES. By O. C. Marsh. The main object of the present paper is to figure, and to describe more fully, several interesting ungulate mammals, which have been previously named and noticed by the writer. A number of others, mostly allied forms, are here described for the first time. The specimens discussed are chiefly from the western part of the country. Some of them from the Miocene, however, are apparently identical with those found on the Atlantic coast, and thus for the first time it is possible to make out a definite horizon in the Tertiary, extending nearly across the continent. Eocene Bunodont Artiodactyles. The Artiodactyles known from the Eocene of this country are few in number, and nearly all small generalized forms. The oldest hitherto found appear to have suilline affinities, but the others cannot be placed with any certainty in any of the existing groups. The first Artiodactyles, so far as now known, are preserved in the lower Eocene, in the horizon named by the writer the Coryphodon beds, and these are all primitive forms. In the middle Eocene, especially in the Dinoceras the remains of these mammals are more abundant, and some of them permit accurate determination. In the upper Eocene, in the Diplacodon horizon, more specialized forms occur, and for the first time resemblance to several modern types can be recognized. Eohyus distans, sp. nov. The present genus was proposed by the writer in 1877, in an address before the American Association for the Advance- ment of Science.* In reviewing the extinct ungulates of this country, the following statement was then made in regard to the present group :— •Introduction and Succession of Vertebrate Life in America, this Journal, vol. xiv, p. 362, 1877.