Patagorhynchus

Patagorhynchus is a genus of prehistoric monotreme mammal from the Late Cretaceous (early Maastrichtian) Chorrillo Formation of Santa Cruz Province, Argentina. The genus contains a single species, Patagorhynchus pascuali. The holotype, MPM-PV-23087, consists of a lower right molar attached to a fragment of the dentary. It was collected near Rio Gallegos, Santa Cruz, Argentina in 2022 and is housed in the Museo Padre Molina.

Etymology
The genus name comes from Patago, referring to Patagonia and Greek rhynchus, meaning nose. The species name pascuali honors Argentine paleomammalogist Rosendo Pascual.

Evolution
Patagorynchus represents the oldest known monotreme species from South America, indicating that they had already arrived in the region by the end of the Cretaceous, and were present in Antarctica during the Late Cretaceous.

Classification
Chimento et al. (2023) recovered Patagorhynchus as a monotreme mammal. The simplified results of their phylogenetic analyses are shown in the cladogram below: