title: BalsscallichirusSakai, 2011 (Decapoda: Axiidea: Callianassidae) in the fossil record: systematics and palaeobiogeography.
abstract: The fossil record of the ghost shrimp genusBalsscallichirusSakai, 2011 (Crustacea: Decapoda: Callianassidae) is revised.BarnardcallichirusSakai, 2011 andTirmizicallichirusSakai, 2011 are considered subjective synonyms ofBalsscallichirus. Based on the examination of extant species it is argued that the morphology of the major cheliped merus, in combination with other hard part morphology characters, is sufficient for assignment of the fossil material into the genus. Main identifying characters are on merus which is keeled along its midline and its lower half is tuberculated; its lower margin possesses broad proximal meral hook continuing into a lobe distally; the entire lower margin is subdivided into numerous irregularly spaced spines. Three species,Callianassa sismondaiA. Milne-Edwards, 1860,C. florianaGlaessner, 1928, andPodocallichirus laepaensisHyžný & Muñiz, 2012, originally described from the Miocene of Italy, Austria and Spain, respectively, are assigned toBalsscallichirusherein.Neocallichirus wellsiSchweitzer, Feldmann & Gingerich, 2004 from the Upper Eocene of Pakistan is tentatively assigned to that genus as well. Spatial and temporal distribution of the genus indicates that at least since the Oligocene, and possibly even sooner (the Late Eocene), the genus has been restricted to the Western Tethys Region. Later, it migrated also into West Atlantic establishing present day communities.
authors: Naturhistorisches Museum Wien, Geologisch-paläontologische Abteilung, Burgring 7, 1010 Vienna, Austria; Present address: Department of Geology and Palaeontology, Faculty of Natural Sciences, Comenius University, Ilkovičova 6, 842 15 Bratislava, Slovakia; e-mail: hyzny.matus@gmail.com.
authors: Matúš
authors: M
authors: Hyžný
keywords: Callianassa; Callianassidae; Decapoda; Podocallichirus; Tirmizicallichirus; fossil record; palaeobiogeography