Brazilian Miocene crabs II. A new genus and species (Crustacea: Decapoda: Brachyura) from Pirabas Formation, northern Brazil

In this study, we describe and illustrate Pirabacarcinus iara n. gen. n. sp., a novel species within the family Pilumnidae, collected from Miocene deposits of the Pirabas Formation, Brazil. Notably, this constitutes the first known fossil Pilumnidae from Brazil and only the second in South America, with the prior record from the Miocene of Chile. Pirabacarcinus iara n. gen. n. sp. is characterized by a series of distinct morphological characters, setting it apart from other known brachyuran species from the Pirabas Formation and other morphologically similar groups. The combination of a carapace with anterolateral margin longer than posterolateral margin, with three blunt spines anteriorly upturned; and a posterior region of carapace, including metabranchial and intestinal regions sloped, metabranchial region without lobes, and intestinal region reduced, faintly delimited set the new species apart from several brachyuran fossil genera. Opportunity is taken to describe and illustrate three cheliped fragments collected from the same locality of the new species.