Boletín de la Sociedad Geológica Mexicana Volumen 65, núm. 2, 2013, p. 307-317 http://dx.doi.org/10.18268/BSGM2013v65n2a12

Archaeoportunus isabenensis, a new genus and species of portunoid crab (Crustacea, Decapoda) from the lower Eocene of Huesca (Spain)

Pedro Artal^1,*, Àlex Ossó², José Luis Domínguez³

¹ Museo Geológico del Seminario de Barcelona, Diputación 231, E-08007 Barcelona, Spain.
² J.V. Foix, 12-H, 1er-1ª, 43007 Tarragona, Catalunya.
³ Padre Manjón, 12, E-50010 Zaragoza, Spain.

^* This email address is being protected from spambots. You need JavaScript enabled to view it.

Abstract

Crabs recovered from marly strata of the upper Roda Formation (lower Cuisian, Ypresian) at Isábena (Huesca, Spain) exhibit a clear set of characters, mainly in chelipeds and dorsal carapace that favour their assignment to the superfamily Portunoidea, and confirm a close relationship with the family Portunidae. However, the presence of important and easily distinguishing features, such as the strongly marked dorsal ridges or notably narrow sternum, lead us to propose a new genus and species, Archeoportunus isabenensis n. gen., n. sp., and a new family, the Archaeoportunidae n. fam. The ventral features of the new taxon, particularly 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, abdomen and pereiopods, substantiate the basal condition of the new taxon within the Portunoidea and also contributes to current knowledge of evolutionary issues within that group.

Keywords: Crustacea, Decapoda, Portunoidea, Archaeoportunus, Archaeoportunidae, new family, Cuisian (Ypresian), Spain.