Anatomy of the Glyptodon

Fossil specimen at the Naturhistorisches Museum, Vienna

The anatomy of Glyptodon has been described over and over again and, because of this and the large number of known specimens, we can break down and describe this anatomy very easily. The vertebral column, eyesight, and skull and associated musculature are of great interest and we could spend a great deal of time on any or all of those individual areas. However, this post is going to specifically treat the most easily recognizable features of Glyptodon: the carapace and tail. The carapace and tail are both covered in osteoderms. Tracing the development of the osteoderms actually coincides with the evolutionary lineage of the species in the genus Glyptodon with specific patterns and sizes of osteoderms appearing across not only the tail and carapace but along the face, legs, and abdomen during the Pleistocene. Osteoderms began appearing in Glyptodon shortly after the North and South American continents were bridged. The current thought is that the osteoderms began becoming more regular and denser as a defensive response to more predatory mammals entering South America from North America. Prior to osteoderm enlargements, the Glyptodon carapace and tail were entirely smooth in appearance. This makes interpretations of Glyptodon somewhat confusing as Late Pleistocene Glyptodon, such as in the first image, are smoother in appearance and very Early Holocene Glyptodon appear to be rough, as in the second image.

Hungarian Natural History Museum