Review and additions to the Maastrichtian (Late Cretaceous) crustacea from Chiapas, Mexico

The Maastrichtian crustacean fauna from Chiapas is illustrated and reviewed with reports of new taxa, including the marine isopod Palaega sp., described for the first time from the lower Maastrichtian Ocozocoautla Formation, represented by molted remains of the posterior carapace. New specimens and a neotype of the raninoid Vegaranina precocia (Feldmann et al., 1996) are illustrated and compared with specimens of Vegaranina sp. from the late Maastrichtian of France. New specimens of Carcineretes woolacotti Withers, 1922, from the late Maastrichtian of Chiapas are reported and recognized as the sole species of the genus, distributed in the upper Maastrichtian lithostratigraphic units from the Caribbean; the new specimens are compared with others of the same species and age from the Guinea Corn Formation in Jamaica and the Barton Creek Formation in Belize. Icriobranchiocarcinus tzutzu Vega new genus and species, is reported as a new member of the Icriocarcininae Števcic, 2005, a diverse subfamily of lithophylacid crabs, along with illustrations and discussion on Branchiocarcinus flectus (Rathbun, 1926) (Maastrichtian, Gulf and Atlantic plains), Icriocarcinus xestos Bishop, 1988 (Maastrichtian, Pacific of California and Baja California), and Lithophylax trigeri A. Milne-Edwards and Brocchi, 1879 (Cenomanian, France), in order to confirm that all of these species belong to the Lithophylacidae Van Straelen, 1936, but to different subfamilies (Lithophylacinae and Icriocarcininae) and genera. Parazanthopsis meyapaquensis Vega, Feldmann, García-Barrera, Filkorn, Pimentel & Avendaño, 2001, is compared with Palaeoxanthopsis cretacea (Rathbun, 1902) (late Maastrichtian, Brazil), and with Palaeoxantho libertiensis Bishop, 1986 (late Maastrichtian, Mississippi), in order to illustrate differences and confirm that these species belong to separate genera. Megaxantho zoque Vega, Feldmann, García-Barrera, Filkorn, Pimentel & Avendaño, 2001 is reviewed and compared to Menippe frescoensis Remy, 1960 (early Eocene, Senegal) and Menippe mercenaria (Say, 1818) (living species, Gulf of Mexico), to confirm the late Maastrichtian species from Chiapas should be recognized as Menippe zoque new combination, representing the oldest confirmed species for the genus. The age and lithostratigraphic units for all these Maastrichtian crustaceans from Chiapas is reviewed and corrected, based on recent data reported by other scientists, who defined the litho and biostratigraphy with macro and