ETYID CRABS (CRUSTACEA, DECAPODA) FROM MID-CRETACEOUS REEFAL STRATA OF NAVARRA,

Decapoda) from the upper Albian – lower Cenomanian Aldoirar coral-gal-dominated patch reef (Albeniz Unit, Eguino Formation), as exposed at the disused Koskobilo quarry in Navarra, northern Spain, are described, discussed and illustrated. A new species, Xanthosia koskobiloensis, the first member of the genus on record from southern Europe, is erected, and a vari-ety that appears closely related to this, Xanthosia cf. X. kosko-biloensis, is recognised. This new taxon could be a forerunner of the early Palaeocene (Danian) Xanthosia gracilis from Fakse (Sjælland, eastern Denmark), with which it shares a morpho-logically closely similar carapace. On the basis of a revised overview here of all species assigned to it, the genus Xanthosia may have evolved in an environment dominated by deposi-tion of siliciclastics, rather than chalks. In addition, Etyxan