Decapod Crustacea of the Central Paratethyan Ottnangian Stage (middle Burdigalian): implications for systematics and biogeography.

Decapod crustaceans from the Ottnangian (middle Burdigalian, Lower Miocene) of the Western and Central Paratethys remain poorly known. In this study, we review and re-describe mud shrimps (), ghost shrimps ( sp., ) and brachyuran crabs of the families Leucosiidae, Polybiidae and Portunidae. A dorsal carapace of the genus is reported for the first time in the fossil record. Re-examination of the type material of (Leucosiidae) and (Geryonidae) resulted in a transfer of these species into (Leucosiidae) and (Polybiidae), respectively. , originally described as a chela of a portunid crab, probably belongs to a member of Polybiidae and is provisionally treated as sp. Only two species, and , are also known from the Karpatian, the succeeding Paratethyan stage. In most cases, the decapod assemblages of the Ottnangian consist of rather shallow-water taxa whereas the assemblages of the Karpatian consist of deep-water taxa from the middle and outer shelf. The Central Paratethyan assemblages show similarities in genus composition to the Proto-Mediterranean and recent Indo-Pacific regions. sp. represents the earliest occurrence of the respective genus in the fossil record. The Oligocene-Early Miocene appearance of and in the circum-Mediterranean implies that sources of present-day diversity hotspots in the Indo-Pacific trace to the Western Tethys (as for other decapod genera), although coeval decapod assemblages in the Indo-Pacific remain poorly known.