A new Aeolosaurini (Sauropoda, Titanosauria) from the Upper Cretaceous of Uruguay

Authors

  • Matías Soto Núñez Instituto de Ciencias Geológicas, Facultad de Ciencias, Iguá 4225, 11400 Montevideo, Uruguay.
  • Felipe Montenegro Instituto de Ciencias Geológicas, Facultad de Ciencias, Iguá 4225, 11400 Montevideo, Uruguay.
  • Daniel Perea Instituto de Ciencias Geológicas, Facultad de Ciencias, Iguá 4225, 11400 Montevideo, Uruguay.

DOI:

https://doi.org/10.5710/AMGH.19.06.2026.3689

Keywords:

Titanosauria, Aeolosaurini, Upper Cretaceous, Guichón Formation, Uruguay

Abstract

The Upper Cretaceous Guichón Formation (northwestern Uruguay) has yielded remains of notosuchian crocodyliforms, iguanodontian
ornithopods, and saltasauroid titanosaurs. Two well-preserved sauropod caudal vertebrae from this unit are described herein from a new locality, Meseta de Artigas. The combination of synapomorphies allows the erection of a new taxon, Mesetasaurus protector gen. et sp. nov. It shares characters with members of the clade Aeolosaurini, such as a strongly anteriorly inclined anterior face, a neural arch placed at the level of the anterior border, an anteriorly inclined neural spine, and long prezygapophyses. A phylogenetic analysis retrieves the new taxon deeply nested within Aeolosaurini. Given that Aeolosaurini is a Coniacian–Maastrichtian clade, this new sauropod provides additional evidence that suggests this age for the Guichón Formation. This is the second record of Aeolosaurini in Uruguay, and the second lineage of titanosaurian sauropods from the unit.

Published

2026-11-06

Issue

Section

Articles

How to Cite

A new Aeolosaurini (Sauropoda, Titanosauria) from the Upper Cretaceous of Uruguay. (2026). Ameghiniana, 63(4). https://doi.org/10.5710/AMGH.19.06.2026.3689