The dentition of Amygdalodon patagonicus (Dinosauria: Sauropoda) and the dental evolution in basal sauropods

CARBALLIDO, J.L.; POL, D.

Comptes Rendus Palevol

Elsevier

Lugar: Paris; Año: 2010 vol. 9 p. 83 - 93

1631-0683

Amygdalodon patagonicus is the oldest record of Sauropoda from South America and isknown from several teeth and fragmentary postcranial remains. Here we describe in detailits dental morphology, characterized by the presence of broad spatulated teeth (with lowSI values) and the absence of denticles in their crowns. The enamel bears a particular wrinklingpattern composed only of apicobasally-aligned pits, which are frequently joined toeach other by a continuous sulcus. Some worn teeth have large wear-facets that extendover only one of the crown’s edges. This unique combination of characters provides a properdiagnosis for Amygdalodon. Despite the fragmentary available material, Amygdalodon is hereinterpreted as a non-eusauropod sauropod based on the results of a phylogenetic analysis.The presence of derived dental characters in Amygdalodon, such as the presence of toothtoothocclusion, shows several features previously thought to diagnose Eusauropoda orGravisauria appeared earlier during the early evolution of sauropods.