more in each individual. The axial skeleton of glyptodonts show extensive fusion in the vertebral column and the pelvis is fused to the carapace, making the pelvis entirely immobile. Glyptotherium was very graviportal and had short limbs that are very similar to those in other glyptodonts. The large tails of glyptodonts likely served as a counterbalance to the rest of the body and Glyptotherium's caudal armor ended in a blunt tube that was composed of 2-3 fused tubes, in contrast to those of South American mace-tailed glyptodonts. The digits of Glyptotherium are very stout and adapted for weight-bearing, though some preserve large claw sheaths that had an intermediate morphology between claws and hooves. During the Pleistocene, the diversity of glyptodonts diminished but increased in size, with the largest known glyptodont, Doedicurus, evolving in the Pleistocene. Glyptotherium weights and sizes vary, but G. texanum was smaller and lighter than the later species, G. cylindricum. One specimen of G. cylindricum was estimated at 350-380 kilograms, compared to 457 kg of its relative Glyptodon reticulatus. The largest estimates of Glyptotherium's mass are based on adult specimens from Brazil and Arizona, with one estimate of a G. cylindricum specimen placing it at and a G. texanum individual at . One specimen of G. cylindricum, AMNH 15548, preserved a carapace length of 1690 centimeters compared to just 1400 cm for MSM P4464, a G. texanum specimen. Glyptotherium texanum differs from G. cylindricum in the configuration of the external sculpturing of symmetrical, hexagonal osteoderms in the dorsal carapace. In the osteoderms of adult G. texanum, the central figures of the osteoderms are flat or weakly convex and very large, while those of G. cylindricum are flat or concave and much smaller. In both species, the central figures of the osteoderms get larger towards the margins of the carapace. Skull and mandible Glyptodont dentition lacks caniniforms or incisiforms and instead have all hypsodont (high crowned teeth adapted for grazing) molariforms, the cheek teeth are some of the most hypsodont and homodont known from terrestrial mammals. Glyptodont skulls have several unique features; the maxilla and palatine are enlarged vertically to make space for the molariforms, while the braincase is brachycephalic, short and flat. Dermal armor wasn't restricted to the carapace and tail, as the skull roof was protected by a "cephalic shield" made of osteoderms. Some paleontologists have proposed that Glyptotherium and some glyptodonts also had a proboscis