New Early Cenozoic ghost shrimps (Decapoda, Axiidea, Callianassidae) from Pakistan and their palaeobiogeographic implications.

A new set of Paleocene and Eocene decapod crustaceans is described from the Kirthar Range of Pakistan. Two new ghost shrimps (Crustacea, Decapoda, Callianassidae) are described: Hyžný & Charbonnier, n. sp. from the Paleocene (Danian, Khadro Formation) of Gawar Band, Ranikot District, and Hyžný & Charbonnier, n. sp. from the Early Eocene (Ypresian, Lakhra Formation) of Rbod Nala, Jhirak District. Both new species exhibit chelipeds which are morphologically surprisingly close to extant (Poore & Griffin, 1979) from the Indo-West Pacific. A group of species sharing this same cheliped morphology is provisionally called the " group" based on , best documented species. The " group" encompasses seven fossil species: the two new Pakistani species, (Lőrenthey Lőrenthey & Beurlen, 1929) n. comb. from the Eocene of Hungary, Beschin, De Angeli, Checchi & Mietto, 2006 from the Eocene of Italy, (Noetling, 1901) n. comb. from the Miocene of Myanmar, (Martin, 1883) from the Miocene of Java and Philippines, and the subfossil (A. Milne-Edwards, 1870) from Thailand. Based upon the extant and fossil occurrences, it is difficult to reconstruct migration pattern of the " group". For now, it can be concluded, that at the genus level, a relative homogeneity of the ghost shrimps is observed between the Eastern and the Western Tethyan regions, as already suggested by Merle (2014) for the assemblage of volutid gastropods from the Lakhra Formation.