New genus and new species of portunoid crab: Archaeoportunus isabenensis from the Lower Eocene of Huesca (Aragon) and Lleida (Catalonia) Nou gènere i nova nova espècie de cranc portunoid: Archaeoportunus isabenensis, de l’Eocè Inferior d’Osca (Aragó) i Lleida (Catalunya)

Crabs recovered from marly strata of the upper Roda Formation (Ypresian) at Isàvena (Huesca, Aragón), and the Ypresian of Lleida (Catalonia), exhibit a clear set of characteristics, mainly in chelipeds and dorsal carapace that favour assignment to the superfamily Portunoidea, and confirm a close relationship with the family Portunidae. However, the presence of important and easily distinguished features, such as the strongly marked dorsal ridges or notably narrow sternum, leads us to erect a new genus and species, Archeoportunus isabenensis gen. nov., sp. nov., and a new family, the Archaeoportunidae fam. nov. The ventral features of the new taxon, in particular the fairly narrow sternum which notably becomes even narrower posteriorly, the strongly downturned sternites 1-4, bearing strong swellings, and the general adaptation of sternum, pleon and pereiopods, substantiates the basal condition of the new taxon within the Portunoidea and also contributes to current knowledge of evolutionary issues within that group.
This publication principally serves to validate the nomenclatural acts in Artal et al. (2013), in order to fulfil the requirements outlined in ICZN (2012).