A new decapod fauna from the Miocene Tuxpan Formation, eastern Mexico

The first formal report of Tertiary portunid crabs for Mexico is based on t wo new species, Portunus atecuicitli and Necronectes tajinensis, from the m iddle Miocene beds of the Tuxpan Formation in Veracruz, east-central Mexico . Associated crustacean remains include fragments of calappid fingers, cala ppid carapace fragments possibly assignable to Matuta Fabricius, and callia nassid hands. Low tolerance to osmotic variations of recent species of Port unus confirms paleoenvironmental interpretations for shallow, euryhaline, t ropical waters during deposition of the Tuxpan Formation.