Punatitan

Punatitan is a genus of titanosaurian sauropod dinosaur from the Late Cretaceous Ciénaga del Río Huaco Formation of La Rioja, Argentina. It contains one species, Punatitan coughlini.

Etymology

The generic name Punatitan refers to the oxygen-depleted atmosphere characteristic of the Andes. The specific name refers to geologist Tim Coughlin, who first reported dinosaur fossils in the discovery locality.

Description

Known from the holotype CRILAR-Pv 614, a partial skeleton composed of the anterior portion of posterior cervical vertebra, two middle dorsal vertebrae, a partial sacrum, 13 articulated caudal vertebrae, the right pubis, the left ischium, and several dorsal ribs, Punatitan was roughly long.

Classification

The describers' phylogenetic analysis places Punatitan as a derived member of the Lithostrotia, in the clade Aeolosaurini, which they recover as a subclade of Rinconsauria, opposite to other analyses. Notably, Punatitan was recovered within a clade consisting of two species of the genus Aeolosaurus, but the describers refrained from assigning it to said genus, instead regarding the more basal species' placement in Aeolosaurus dubious. However, with the reassignment of "Aeolosaurus" maximus to the genus Arrudatitan in 2021, Punatitan's generic separation could be justified.
Their cladogram is shown below:

Paleoenvironment

The holotype locality, the Quebrada de Santo Domingo site, preserves one of the largest concentrations of titanosaur eggs in the world. The describing authors suggest some connection with either Punatitan or its contemporary Bravasaurus, which was described in the same paper.