title: Decapod Crustacea of the Central Paratethyan Ottnangian Stage (middle Burdigalian): implications for systematics and biogeography.
abstract: 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 (Jaxea kuemeli), ghost shrimps (Gourretiasp.,Calliax michelottii) and brachyuran crabs of the families Leucosiidae, Polybiidae and Portunidae. A dorsal carapace of the genusCalliaxis reported for the first time in the fossil record. Re-examination of the type material ofRandallia strouhali(Leucosiidae) andGeryon ottnangensis(Geryonidae) resulted in a transfer of these species intoPalaeomyra(Leucosiidae) andLiocarcinus(Polybiidae), respectively.Achelous vindobonensis, originally described as a chela of a portunid crab, probably belongs to a member of Polybiidae and is provisionally treated asLiocarcinussp. Only two species,J. kuemeliandC. michelottii, 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.Gourretiasp. represents the earliest occurrence of the respective genus in the fossil record. The Oligocene-Early Miocene appearance ofPalaeomyraandLiocarcinusin 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.
authors.affiliation: Geological-paleontological Department, Natural History Museum Vienna, Burgring 7, 1010 Vienna, Austria ; Department of Geology and Paleontology, Faculty of Natural Sciences, Comenius University, Ilkovičova 6, 842 15 Bratislava, Slovak Republic.
authors.forename: Matúš
authors.initials: M
authors.lastname: Hyžný
authors.affiliation: Geological-paleontological Department, Natural History Museum Vienna, Burgring 7, 1010 Vienna, Austria.
authors.forename: Mathias
authors.initials: M
authors.lastname: Harzhauser
authors.affiliation: Hauptstrasse 83, 4794 Kopfing, Austria.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Danninger
keywords: Central Paratethys; Crustacea; Decapoda; Early Miocene; Ottnangian