In the country east of the Rocky Mountains, including the states of Dakota, Nebraska, Wyoming, and part of Colorado, Professor Marsh has discovered the remains of yet another strange group of large quadrupeds. The best known of these is Brontops, of which the skeleton is seen in Fig. 45. These animals lived after the Dinocerata, namely, in the Miocene period, and were the largest American mammals of that period. They constitute a distinct family more nearly allied to the rhinoceros than to any other living form. The skeleton on which Fig. 45 is founded was the most complete of any yet discovered by Professor Marsh. Portions of it were exhumed at different times, but it was first found in 1874. Our artist has made the restoration seen in Plate XV. from this skeleton, as figured by Professor Marsh.
A HUGE EXTINCT MAMMAL FROM NORTH AMERICA. BRONTOPS ROBUSTUS.]
This strange group of creatures flourished in great numbers on the borders of an old lake of Miocene age. The Brontops was a heavy massive animal, larger than any of the Dinocerata, with a length of twelve feet, not including the tail, and a height of eight feet. The limbs are shorter than those of the elephant, which it nearly equalled in size. As in the tapir, there were four toes to the front limbs, and three to the hind limbs. Its skull was of a peculiar shape, shallow, and very large. That of Brontops ingens is thirty-six inches long, and twenty inches between the tips of the two horns, or protuberances. The creature was probably provided with an elongated, flexible nose, like that of the tapir, but not longer, because the length of the neck shows that it could reach the ground without the aid of a trunk such as the elephant's. It is doubtful if the two prominences on the front of the skull were provided with horns, for, if directed forwards, they would interfere with the animal when grazing.
[Illustration: Fig. 45.--Skeleton of Brontops robustus. (After Marsh.)]
"What a glorious privilege it would be, could we live back--were it but for an instant--into those ancient times when these extinct animals peopled the earth! to see them all congregated together in one grand natural menagerie--these mastodons and elephants, so numerous in species, toiling their ponderous forms and trumpeting their march in countless herds through the swamps and reedy forests!"--Hugh Falconer.