GLYPTODONT, an armored edentate mammal of the extinct family glyptodontidie, which developed mainly in South America dur ing the Tertiary Period. Several genera and many species have been described from Pata gonia, the Argentine pampas, Peru, etc., and northward to the southern United States, asso ciated with the great ground-sloths. These glyptodonts were allies of the arinadilloes, and some of the more ancient species of the pam pean region were very armadillo-like. As time advanced, however, the race developed into huge and grotesque species, the larger ones reaching a total length, including the tail, of 12 or 14 feet, and standing five feet high. Their gen eral appearance must have been that of gigantic, high-backed, long-tailed tortoises; their squarish heads were turtle-like in shape; and their movements must have been slow and heavy, fgr these animals were massively armored against the big and savage beasts of their time. The to of the head was protected by a bony casque. The body and much of the limbs were enclosed in an immense domed carapace, which almost reached the ground at the sides. °It was composed of very thick polygonal plates of bone (no doubt covered externally with horny plates) immovably fixed together by their rough edges, and ornamented with an elaborate pattern of sculpture which varied with the genus' The tail, often exceeding the body in length, was enclosed in a defensive sheath of the same nature, and constituted an extraor dinary and powerful weapon of defense. In Glyptodon it was made up of a series of over lapping rings, each ring double and brist: ling with sharp spikes. In Sclerocalyptus there were several rings, around the root of the tail, diminishing posteriorly, and then blending into a long, smooth, somewhat flattened tube of bone, blunt at the tip. In Panocthus this tube
carried a few heavy, horn-like spikes; and in Dwdicurus the very long tube Thad its free end greatly expanded and thickened into a huge, club-shaped mass, on the top and sides of which were fixed long and sharp horns?' The skeleton was of the armadillo type, but modified and strengthened, especially in the spine and legs, to enable it to bear the great weight of the carapace; and the hind legs were much longer than the fore legs, giving the hips a humped appearance. The broad feet had five toes in each pair, and in some species these were armed with powerful claws to enable them to dig roots and tubers. All the glyptodonts were plant-feeders, and entirely harmless.
attacked by the saber-toothed tigers (Smitodon) or the great bears (Arctotherium) they needed only to squat down, bringing the edges of the carapace to the ground, and draw in the head,' says Scott,
be perfectly protected, while a sweep of the spiny and club-like or horny tail would have been fatal to everything in its path' The Texan species (Gomphotherium) was smaller, had .less armament and a shorter tail, ztati. survived .on. the Mexican border, ac cording to Osborn, until near the close of the Ice Age. Consult Woodward, 'Vertebrate Paleontology) (London 1898) • Ingersoll,