Revealing the diversity of Paleogene cingulates from Brazil: a new species of Parutaetus (Euphractinae) in the Guabirotuba Formation (middle–late Eocene)

Abstract

Parutaetus is an early-diverging Euphractinae cingulate that inhabited South America during the middle Eocene–early Oligocene. Four species are known: P. chicoensis, P. clusus, P. chilensis, and P. punaensis. Here, we describe a new species of this genus from Guabirotuba Formation (middle-upper Eocene of Brazil). The osteoderms differ from other species of the genus by presenting: (i) more surface glandular and piliferous foramina; (ii) the articulation surface of the area between the osteoderms is flat and full of pronounced, round, and anastomosed projections forming serratedexternal and medial edges with a median projection (indentations); and (iii) larger size than other species of the genus. In combination, this suite of traits is not present in other species of the genus. The increase in the number of surface glandular and piliferous foramina may be associated with the global cooling that occurred during the middle–late Eocene that affected the South American fauna. Finally, the new species expands the knowledge about the diversity of taxa that inhabited southeast South America during the Paleogene.