cylindricum meaning "cylindrical" is after the cylindroid anatomy of the premolars in the holotype of G. cylindricum. History and taxonomy Fossils attributable to Glyptotherium have been found as early as the 1870s, when civil engineers J. N. Cuatáparo and Santiago Ramírez collected a skull, nearly complete carapace, and associated postcranial skeleton of a glyptodont from a drainage canal near Tequixquiac, Mexico, the fossils coming from the Rancholabrean Pleistocene. This was the first discovery of a glyptodont in North America. Cuatáparo and Ramírez named the fossils Glyptodon mexicanum in 1875, but the fossils have been lost. Another species of Mexican Glyptodon was described in 1889, G. nathoristi, by German paleontologists based on carapace remains from Pleistocene localities in Ejutla, Oaxaca. Both of these species have since been synonymized with G. cylindricum. The first Glyptotherium fossils to be described from the United States were described in 1888 by paleontologist Edward Drinker Cope and consisted only of a single carapace osteoderm that had been collected from the Lower Pleistocene “Equus Beds” of Nueces County, Texas. Cope named his osteoderm Glyptodon peltaliferus, but Cope did not give the species a proper description that followed ICZN rules, making it a nomen nudum and it has since been synonymized with G. cylindricum . The next year, Joseph Leidy named Glyptodon floridanus based on isolated carapace osteoderms and pieces of caudal armor, though some were also referred to G. peltaliferus, that were collected from Pleistocene deposits in DeSoto County, Florida. This species is now seen as a nomen vanum and synonymous with Glyptotherium cylindricum. Glyptotherium wasn't named until 1903 when fossils collected by an American Museum of Natural History expedition led by J. W. Gidley to the Early Pliocene strata from the Blanco Formation of Llano Estacado, Texas were described by Henry Fairfield Osborn as a new genus and species of glyptodont, Glyptotherium texanum. The fossils were deposited at the AMNH and consist of a carapace and associated postcranial elements, one of the few G. texanum skeletons known. The skeleton was put on display in the exhibit hall of the AMNH where it remains today. Another find came in 1910 when, while traveling in Jalisco, Mexico, fossil hunter Barnum Brown collected a complete dorsal carapace and several additional fossils, including teeth, of a single individual from the Pleistocene strata of the area. The specimen was sent to the American Museum of Natural History as well, where it