This jewel-like work of art is a product of nature: it is the thin section of a bone thorn that adorned the shell of a herbivorous ankylosaur almost 70 million years ago.
When it comes to dinosaur fossils, we mostly think of huge fossilized bones. In some sites, such whole skeletons of the primeval giant lizards have actually been preserved. Sometimes, however, only tiny relics remain of the former giants of the dinosaur era – teeth, bits of bone or the few millimeters of bone scales, so-called osteoderms, with which the shells of some herbivorous dinosaurs were covered.
Ariana Paulina-Carabajal from the National University of Comahue in Argentina and her colleagues recently discovered a whole collection of such teeth and osteoderms in southern Patagonia. More detailed analyzes showed that not only carnivorous dinosaurs such as the abeliosaurs and long-necked titanosaurs cavorted at this site during the late Cretaceous period, but also prehistoric crocodiles and herbivorous dinosaurs from the ankylosaur group. These stout, up to nine meters long herbivores protected themselves against attacks from enemies by thick bone armor.
Some of the bone scales of this armor have been preserved in the rock of the Patagonian site. The image above shows a thin section of one of the osteoderms preserved in the rock. The size and internal structure of these bone scales allowed paleontologists to attribute these relics to the various species of ankylosaurs.
“Sometimes we just don’t have skeletons. Then only tiny fossils such as teeth and dermal bone scales reveal the variety of dinosaurs and crocodiles that once romped about here, ”says Paulina-Carabajal. “Our finds reveal a species-rich community of these animals that has not yet been documented in this form.”