Glyptodon

Glyptodon Temporal range: Pliocene?-Pleistocene (Montehermosan?–Lujanian) ~3.200–0.011 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Skeleton of G. clavipes at the Naturhistorisches Museum, Vienna
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Cingulata
Family:	Chlamyphoridae
Subfamily:	†Glyptodontinae
Genus:	†Glyptodon Owen, 1839
Type species
†Glyptodon clavipes Owen, 1839
Other Species
†G. elongatus? Burmeister, 1866 †G. jatunkhirkhi Cuadrelli et al., 2020 †G. munizi Ameghino, 1881 †G. reticulatus Owen, 1845
Distribution of Glyptodon (green) compared to Glyptotherium's (orange).
Synonyms
Genus synonymy Chlamydotherium Bronn, 1838 Orycterotherium Bronn, 1838 Lepitherium Sainte-Hilaire, 1831 Pachypus D'Alton, 1839 Schistopleurum Nodot, 1857 Thoracophorus Gervais and Ameghino, 1888 (preoccupied) Neothoracophorus Ameghino, 1889 Paraglypytodon Castellanos, 1943 Glyptocoileus Castellanos, 1952 Glyptopedius Castellanos, 1953 Heteroglyptodon Roselli, 1976 Synonyms of G. clavipes G. subelevatus Nodot, 1854 Synonyms of G. reticulatus G. typus Nodot, 1857 Schistopleurum typus (Nodot, 1857) G. robustus Burmeister, 1866 G. asper Burmeister, 1866 Hoplophorus asper (Burmeister, 1866) Schistopleurum asperus (Burmeister, 1866) Dubious species Paraglyptodon uquiensis Castellanos, 1943 Glyptodon uquiensis (Castellanos, 1943) Heteroglyptodon genuarioi Roselli, 1976

Glyptodon (lit. 'grooved or carved tooth'; from Ancient Greek γλυπτός (gluptós) 'sculptured' and ὀδοντ-, ὀδούς (odont-, odoús) 'tooth')^[1] is a genus of glyptodont, an extinct group of large, herbivorous armadillos, that lived from the Pliocene, around 3.2 million years ago,^[2] to the early Holocene, around 11,000 years ago, in South America. It is one of, if not the, best known genus of glyptodont. Glyptodon has a long and storied past, being the first named extinct cingulate and the type genus of the subfamily Glyptodontinae. Fossils of Glyptodon have been recorded as early as 1814 from Pleistocene aged deposits from Uruguay, though many were incorrectly referred to the ground sloth Megatherium by early paleontologists.

The type species, G. clavipes, was described in 1839 by notable British paleontologist Sir Richard Owen. Later in the 19th century, dozens of complete skeletons were unearthed from localities and described by paleontologists such as Florentino Ameghino and Hermann Burmeister. During this era, many species of Glyptodon were dubbed, some of them based on fragmentary or isolated remains. Fossils from North America were also assigned to Glyptodon, but all of them have since been placed in the closely related genus Glyptotherium. It was not until the later end of the 1900s and 21st century that full review of the genus came about, restricting Glyptodon to just five species under one genus.

Glyptodonts were typically large, quadrupedal (four-legged), herbivorous armadillos with armored carapaces (top shell) that were made of hundreds of interconnected osteoderms (structures in dermis composed of bone). Other pieces of armor covered the tails and skull roofs, the skull being tall with hypsodont (high-crowned) teeth. As for the postcranial anatomy, pelves fused to the carapace, an amalgamate vertebral column, short limbs, and small digits are found in glyptodontines. Glyptodon reached up to 2 meters (6.56 feet) long and 400 kilograms (880 pounds) in weight, making it one of the largest glyptodontines but not as large as its close relative Glyptotherium or Doedicurus, the largest known glyptodont. Glyptodon is morphologically and phylogenetically most similar to Glyptotherium, however they differ in several ways. Glyptodon is larger on average, with an elongated carapace, a relatively shorter tail, and a robust zygoma, or cheek bone.

Glyptodonts existed for millions of years, though Glyptodon itself was one its last surviving members. Glyptodon was one of many South American megafauna, with many native groups such as notoungulates and ground sloths reaching immense sizes. Glyptodon had a mixed diet of grasses and other plants, instead living at the edge forests and grasslands where the shrubbery was lower. Glyptodon had a wide muzzle, an adaptation for bulk feeding. The armor could have protected the animal from predators, of which many coexisted with Glyptodon, including the "saber-tooth cat" Smilodon, the large canid Protocyon, and the giant bear Arctotherium.

Glyptodon, along with all other glyptodonts, became extinct at the end of the Late Pleistocene, around 12,000 as part of the Late Pleistocene extinctions, along with most large mammals in the Americas. Evidence of hunting of glyptodonts by recently arrived Paleoindians suggests that humans may have been a causal factor in the extinctions.