United States or Somalia ? Vote for the TOP Country of the Week !
Many trails led through the woods, and especially along the borders of the swamp; and, although their principal makers had evidently been cattle, yet there were in them footprints of both tapir and deer. The tapir makes a footprint much like that of a small rhinoceros, being one of the odd-toed ungulates. We could hear the dogs now and then, evidently scattered and running on various trails.
It is to be supposed that these new regions offered themselves to the Miocene Ungulates, as South America and Australia offered themselves to the cattle, sheep, and horses of modern colonists.
Darwin contends, the natural selection of these favourable variations has alone lengthened the neck of the giraffe by preserving it during droughts; similar variations, in similarly-feeding forms, at the same times, ought similarly to have been preserved and so lengthened the neck of some other Ungulates by similarly preserving them during the same droughts.
The charge of the rhinoceros and other great ungulates is probably always a fear reaction. They appear to have no other aggressive impulses, certainly none connected with the nutritional motives since they are herbivorous in habit.
Even to an uncritical eye, the differences between ungulates and carnivores of to-day are many and obvious, but as we trace them back into the past we follow on converging lines, and in our search for the prototypes of the carnivora we are led to the Creodonta, contemporary with Condylarthra, which we have seen giving origin to hoofed beasts, but outlasting them into the succeeding age.
The dog-family seems to have developed chiefly in North America. As in the case of the Ungulates, we find many strange side-branches which flourished for a time, but are unknown to-day. Machoerodus, usually known as "the sabre-toothed tiger," though not a tiger, was one of the most formidable of these transitory races.
All non-ruminant ungulates have from four to six incisors in the upper jaw; the canines are present, and sometimes, as in the wart hogs, reach an extraordinary size.
The rat and squirrel and rabbit, on their part, remain together until long after they take leave of the carnivora and ungulates; while the sheep and cattle and pigs have their own branch line, which they follow in company after leaving the embryos of the other orders.
So at last, group by group, we have gone through the ungulates, and the bisons alone are left, and as the American animal has short, incurved horns, set low down on the skull and far apart at the base; premaxillaries falling short of the nasals; the last cervical and the anterior dorsal vertebrae with spines; fourteen pairs of ribs, and a mane covering the shoulders, we conclude that it is a bison, and as the same characteristics with minor variations are shown by the European species, often, but wrongly, called "aurochs," we say that these two alone of existing Bovidae are bisons, with the yak as a somewhat questionable relative.
While the cutaneous glands are inner growths of the epidermis, the appendages which we call hairs and nails are external local growths in it. The lower mammals usually have claws instead of them; the ungulates, hoofs. The stem-form of the mammals certainly had claws; we find them in a rudimentary form even in the salamander.
Word Of The Day