DIPLOD'OCUS (Neo-Lat., from Gk. borX6or, diptous, double 1 dokus, beam). A gigan tic fossil reptile of the order Din0sauria, sub order Sauropoda, found in the Jurassic nicks of western North America. Its body was long and low, its head remarkably small, its neck very lung, trunk short and deep, and the tail was very long and quite thick at the base. The legs were strongly built and of almost equal length, indi cating quadrupedal locomotion. and the feet were armed with heavy claws. The skull was high and laterally compressed posteriorly. with a long sloping face, and with large orbits situated far hack on the sides. The jaws had weak, slender, spreading teeth only in their anterior portions, all the premolars and molars being absent. The vertebra' of Diplodoeus are of great interest be cause of the elaborate systems of plates and but tresses that give support to the vertebral pro cesses and thus lend great strength without much increase of weight. The animal appears to have been herbivorous, and was probably aquatic, liv ing in the extensive marshes and swamps of the Jurassic seas and lowlands that probably re sembled those of the modern Amazon and Congo basins. Some figures. based upon the skeletal
mounted in the Carnegie Museum at Pittsburg, express more clearly the immense proportions of this ancient reptile. The total length, from tip of nose to tip of tail, was about (10 feet, and its height was nearly 12 feet. The head was 2 feet long, only one-thirtieth of the length of the body, and the neck 20 feet in length. The trunk, from the point of the shoulder-blade to the middle of the sacrum, measured 13 feet. and had a depth of 7 to S feet, and the tail was at least 25 feet long. The animal is estimated to have weighed, when alive, about twenty tons. and to have required a daily meal of at least 500 pounds of vegetable food such as the twigs, leaves, and succulent stems of plants that grew in the waters of its habitat. Consult: lIatcher, "Diplodocus. Marsh, Its Os teology, Taxonomy, and Probable Ilabits." Me moirs of the caracole JI useum, vol. i., No. 1 (Pittsburg, 1901) ; Lucas. .1 abacus of the Past (New York. 1901). See DINOSAUR] A.