A giant tooth from the Late Cretaceous of Patagonia, Argentina: an enormous titanosaur or a large toothed titanosaur?

Abstract

The tooth MML-Pv 1030 comes from the Upper Cretaceous (middle Campanian–lower Maastrichtian) strata of the Allen Formation at Salitral de Santa Rosa, Río Negro, Argentina and is the biggest titanosaur tooth yet described. The specimen is a cylindrical chisel-like tooth, its length is 75 mm, mesiodistally 15 mm and labiolingually 11 mm. The wear facet is single on the lingual side of the tooth, which has an oval outline with a low angle (10°) with respect to the axial axis of the tooth. This tooth is 32% greater in length than the longest tooth registered in a titanosaurid (Nemegtosaurus), and twice the tooth size of taxa as Tapuiasaurus, Bonitasaura and Pitekunsaurus. Detailed descriptions of the tooth morphology and a highlight of comparative relationships among known titanosaur teeth are provided. Finally, different aspects are suggested related to morphology and feeding behavior.