_Baluchitherium_, the largest land mammal known to science, was a hornless rhinoceros that lived in late Oligocene and early Miocene time. This immense creature measured approximately 25 feet from head to tail, stood almost 18 feet high at the shoulder, and must have weighed many tons. Remains of these creatures have not been discovered in North America, and they appear to have been restricted to Central Asia.
The artiodactyls are the even-toed hoofed mammals and include such familiar forms as pigs, camels, deer, goats, sheep, and hippopotamuses. This is a large and varied group of animals, but the basic anatomical structure of the limbs and teeth show well the relationship between the different forms. Artiodactyls are abundant fossils in rocks ranging from Eocene to Pleistocene in age and are common in rocks of this age in Texas.
These giant pig-like artiodactyls lived during Oligocene and early Miocene time and were distinguished by a long heavy skull that held a relatively small brain. The face was marked by large knobs which were located beneath the eyes and on the underside of the lower jaw, and although these knob-like structures were blunt they had the appearance of short horns. Certain of these giant swine attained a height of 6 feet at the shoulders and had skulls that measured 3 feet in length (Pl. 46). Entelodont remains have been found in the Miocene of the Texas Coastal Plain.
The first known camels have been reported from rocks of upper Eocene age, and these small forms underwent considerable specialization of teeth and limbs as they developed in size. Many of the camels that lived during the middle Cenozoic had long legs which were well adapted to running and long necks which would have allowed the animals to browse on the leaves of tall trees.
The earliest known Texas camels were found in rocks of Oligocene age, and camels, like horses, must have been abundant in Texas during the Pleistocene for their fossilized remains are common in many parts of the State.
[Illustration: Plate 49 CENOZOIC MAMMALS]
WOOLLY RHINOCEROS × ¹/₂₀ WOOLLY MAMMOTH × ¹/₄₀
The following books are recommended for the reader who wants to know more about fossils and fossil collecting. The publications listed below cover various phases of historical geology and paleontology and range from children’s books to the more technical publications of the professional paleontologist. This list, however, is by no means all-inclusive and many other interesting and useful publications are available.