Mark Wilson December 29th, 2013
This is a tiny bit of a large and fascinating Pleistocene animal from Central and South America. It is Glyptodon, an impressively large mammal with bony armor much like its cousin the armadillo. The above fossil is a fragment of that carapace. Each roundel is called a scute.
This is a side view of the above carapace fragment showing its thickness and layered, bony nature.
This modern reconstruction of Glyptodon (from Wikipedia with a GNU free documentation license) shows its primary features, including the bony shell (the size and shape of a Volkswagen Beatle, as is often stated) and its characteristically large claws. It belongs to the Superorder Xenarthra, which includes armadillos, sloths and anteaters. I see the resemblance. They could not completely go turtle, as it were, but it could pull its head back enough into the shell that the scutes on the top of the skull would protect it like a cap. They had massive jaws and flat grinding teeth typical of a large herbivore. Its squat skeleton had a variety of features to support the heavy shell, including fused vertebrae and elephant-like short, stout limbs. They went extinct only about 10,000 years ago, possibly having been hunted to oblivion by early Americans. There is even some evidence that people used their empty shells as shelters.
Glyptodon was formally named as a genus in 1839 by the extraordinary Sir Richard Owen (1804-1892). Owen was a giant of natural history through most of the 19th Century. He is most remembered for inventing the term Dinosauria (“terrible lizards”) and for being on the wrong side of history at the beginning of the Darwinian Revolution. He was apparently ambitious to the point of severity, and very tough on his contemporary scientists. Thomas Henry Huxley, for example, despised Owen for his treatment of his colleagues. Ironically, Huxley did considerable work on further describing Glyptodon in 1865. Owen had vision as well as sharp observational skills. He was a primary force in the eventual establishment of the Natural History Museum in London in 1881. It can be argued that this museum set the high standards of accessibility and research we now expect from all such institutions. Sir Richard Owen is such a large and well known figure I can simply refer you to one of many websites describing Owen’s life and contributions.
This post marks three complete years of Wooster’s Fossil of the Week. That’s 156 posts. You can visit the very first post (about a Devonian tabulate coral) and see how the entries have evolved, so to speak. We still have plenty more fossils to describe!
Gallo, V., Avilla, L.S., Pereira, R.C. and Absolon, B.A. 2013. Distributional patterns of herbivore megamammals during the Late Pleistocene of South America. Anais da Academia Brasileira de Ciências 85(2): 533-546.
Huxley, T.H. 1865. On the osteology of the genus Glyptodon. Philosophical Transactions of the Royal Society of London 155: 31-70.
Oliveira, É.V., Porpino, K.O. and Barreto, A.F. 2010. On the presence of Glyptotherium in the Late Pleistocene of northeastern Brazil, and the status of “Glyptodon” and “Chlamydotherium“. Paleobiogeographic implications. Neues Jahrbuch für Geologie und Paläontologie-Abhandlungen 258(3): 353-363.
Owen, R. 1839. Description of a tooth and part of the skeleton of the Glyptodon, a large quadruped of the edentate order, to which belongs the tessellated bony armor figured by Mr. Clift in his memoir on the remains of the Megatherium, brought to England by Sir Woodbine Parish. FGS Proceedings of the Geological Society of London 3: 108-113.