A history of land mammals in the western hemisphere

by William Berryman Scott

8. Cervidæ. Deer

In most of the deer now existing the male has antlers. The antler is a bony outgrowth from the frontal bone of the skull and is annually shed and replaced, increasing, as a rule, in size and in the number of branches with each renewal. During the period of growth the antler is richly supplied with blood-vessels and covered with skin and is then said to be “in the velvet,” which dries and peels off when growth is complete; after the rutting season a layer of bone at the base of the antler is resorbed, loosening the antler, which is then shed. There is, however, a permanent, cylindrical process, of greater or less length, from each frontal, the “pedicle,” from which the antler is annually reproduced, and around the base of the antler and shed with it is a roughened ring, the “burr.” Among the different genera of deer there is great variety in the form and size of the antler, from a single spike to the immense and complicated appendages of the Wapiti (Cervus canadensis). As a rule, the “beam” or main stem of the antler and its branches or “tines” are cylindrical and tapering; but in some cases, as in the Moose (Alce) and the Fallow Deer (Dama), the antler is very broad and flat and is then said to be “palmated.” Except in the Reindeer and Caribou (Rangifer) the female is without antlers.

In the skeleton there is little difference between the deer and the Cavicornia, but there are some differences in the teeth. In the males of those deer which have no antlers, such as the Musk-Deer (Moschus moschiferus) and the Chinese Water-Deer (Hydropotes inermis), as well as in certain forms with very small antlers, like the muntjacs of Asia (Cervulus and Elaphodus), the upper canine is a long, thin, recurved and sabre-like tusk, a very effective weapon. Speaking of the Indian Muntjac or “Barking Deer” (Cervulus muntjac), Flower and Lydekker say, “When attacked by dogs the males use their sharp canine teeth with great vigour, inflicting upon their opponents deep and even dangerous wounds.” In other forms of deer the upper canines are small or absent. The grinding teeth are brachyodont, but in the existing genera they have higher crowns than in the Tertiary progenitors of the family, and in the Axis and Hog Deer of India (Axis axis and A. porcinus) the molars are quite hypsodont.

As was shown in [Chapter V], the existing deer of North America are of two kinds: (1) the northern, which are plainly of Old World origin and so closely similar to Old World species that many naturalists deny the necessity of making distinct species for the American forms. The best known of these are the Wapiti (Cervus canadensis), the Caribou (Rangifer caribou) and the Moose (Alce americanus). (2) The southern deer, of which the common Virginia Deer (Odocoileus virginianus) is a familiar example, though overlapping in their range that of the northern genera, are peculiar to the Americas, and, though not exactly autochthonous, they must have had a long American ancestry. In the Pleistocene we find the same genera and mostly the same species, their distribution over the continent shifting in accordance with the many climatic changes of that epoch. There was, however, at least one Pleistocene genus (†Cervalces) different from any now living and different from any known in the eastern hemisphere. The most complete specimen of this animal is a skeleton in the museum of Princeton University, found beneath a bog in northern New Jersey, though other bones, collected in Kentucky and elsewhere, are very probably referable to it. †Cervalces was very nearly related to the Moose, the neck, body, limbs and feet being almost identical in the two genera, but the skull and antlers were notably different; the nasal bones were not nearly so much shortened as in the Moose, indicating that the proboscis-like snout was not so large or inflated as in the latter. The antlers were quite unique; though in general like those of the Moose, they were much less palmated and they had, in addition, a great trumpet-like plate of bone on the lower side of each antler (see [Fig. 117, p. 209]), such as occurs in no other known member of the family. Although †Cervalces has not been found in the Old World, it was almost certainly an immigrant from eastern Asia.

The Moose, Caribou and Wapiti were unquestionably immigrants and came in not earlier than the Pleistocene. Nothing is known in the Pliocene or more ancient Tertiary epochs of North America which could be twisted into forms ancestral to these typically Old World genera. With the southern deer (Odocoileus, etc.) the matter stands differently, for these have a probable American ancestry extending back to the lower Miocene and possibly much farther. On the other hand, it is not altogether certain that these may not have been Pliocene immigrants, for their genealogy is still in an extremely fragmentary and unsatisfactory condition. The North American genus, Odocoileus, extended back to the Pliocene with very little change. The annoying, unrecorded gap of the upper Pliocene and the meagre representation of the middle Pliocene mammals given by the Blanco leave us without information regarding the deer of that time. In the lower Pliocene and through the whole Miocene we meet with frequent remains of a genus (†Blastomeryx) which was quite probably the ancestor of the American types of deer. It was considerably smaller than any of the existing North American species and had no antlers, but possessed the sabre-like, upper canine tusks, which characterize the muntjacs and hornless deer of Asia. The limb-bones had already attained nearly their present state of development, as regards the reduction of ulna and radius, formation of cannon-bones, etc. †Blastomeryx probably entered North America in the lower Miocene, but, as was mentioned previously ([p. 409]), Dr. Matthew and Professor Osborn regard the genus as autochthonous and descended from the †Hypertragulidæ.

Fig. 221.—Lower Miocene †hornless deer (†Blastomeryx advena). Restored from a skeleton in the American Museum of Natural History.

In the middle Miocene †Blastomeryx gave rise to an aberrant genus (†Merycodus) which has been made the type of a distinct family (†Merycodontidæ, see table, [p. 362]), but this is perhaps unnecessary. †Merycodus had deer-like antlers, but completely hypsodont teeth such as no known member of the Cervidæ possesses. The middle Miocene species (†M. osborni) was a little creature, not more than eighteen or twenty inches high at the shoulder, and had a branched antler of three tines, which was considerably longer than the skull, while in the species of the upper Miocene (†M. furcatus) the antler was shorter and simply forked. From the number of specimens of these animals found in which the burr is incomplete or absent, it may be inferred that the antler was not always deciduous. The legs were long and very slender, and apparently there was no trace of the lateral digits, even in the fore foot. These peculiar hypsodont deer persisted even in the older Pleistocene.

Fig. 222.—Miocene †deer-antelopes (†Merycodus osborni, middle Miocene, and †M. furcatus, upper Miocene). Restored from specimens in the American Museum.