Glyptodont

Glyptodonts first evolved during the Eocene in South America, which remained their center of species diversity. For example, an Early Miocene glyptodont with many primitive features (comparatively to other species), Parapropalaehoplophorus septentrionalis, was discovered at a now-elevated site in Chile and described in 2007. After the Isthmus of Panama formed about three million years ago, the genus Glyptotherium spread north as part of the Great American Interchange, as did pampatheres, armadillos and a number of other types of xenarthrans (e.g., ground sloths). }} Analysis of inner ear morphology corroborates this position, while also finding that pampatheres are the closest relatives of glyptodonts: Cladogram after Barasoain et al. 2022: }} }} }} }} }}}}}}}}}}}}}}}}}}}}}} == Description ==

and Glyptodon by Robert Bruce HorsfallThe largest glyptodonts like Doedicurus'' reached a height of and in length, with a body mass of over two tonnes. The body of glyptodonts was covered in a large immobile carapace made up of hundreds of bony scutes/osteoderms, with the underside of the body and the top of the head also being protected with osteoderms. This protection reached a thickness of . The vertebrae of the back were extensively fused to each other. The limbs were short and robustly built, with the pectoral girdle being wide. The head was short and blunt, with deep jaws. The teeth were grooved, and were evergrowing. == Ecology ==

Glyptodonts are thought to have been herbivores that fed on low lying vegetation, with mixed feeding or grazing based diets. Some glyptodonts were likely selective feeders, while others were likely bulk feeders. Damage to some glyptodont carapaces suggested to be caused by tail club impacts suggests that tail clubs may have been used in combat between glyptodonts, perhaps in sexual contests between males. , early Miocene, in the permanent collection of The Children's Museum of Indianapolis == Extinction ==

At the end of the Late Pleistocene, all then-living glyptodont species, which belonged to the genera Glyptodon, Hoplophorus, Glyptotherium, Panochthus, Neuryurus, Doedicurus and Neosclerocalyptus, abruptly became extinct around 12,000 years ago as part of the end-Pleistocene extinction event, simultaneously with the vast majority of other large mammals in the Americas. These extinctions followed the first arrival of humans in the Americas, and the importance of human vs climatic factors in these extinctions has been the subject of contention. Several sites across South America are suggested to document hunting of glyptodonts by the recently arrived Paleoindians, which may have played a role in their extinction. At the Muaco and Taima-Taima sites in Falcón State in northwestern Venezuela, several skulls of Glyptotherium display distinctive fracture marks on the skull roof that occurred around the time of death, suggested to have been caused by a deliberate percussive blow to a relatively thin part of the skull by a club or stone tool. == References ==