title: Deep-water fossorial shrimps from the Oligocene Kiscell Clay of Hungary: Taxonomy and palaeoecology.
abstract: We describe deep-water ghost shrimp assemblages from the otherwise well known Oligocene Kiscell Clay in Hungary. The described fossorial shrimps (Decapoda: Callianassidae and Ctenochelidae) include:Ctenocheles rupeliensis(younger synonymCallianassa nuda) andLepidophthalmus crateriferus(younger synonymCallianassa brevimanus). The fossil material of the former species is assigned toCtenochelesbased on the morphology of the major cheliped, particularly the pectinate fingers, bulbous propodus, cup-shaped carpus and elongated merus.Lepidophthalmus crateriferusfrom the Oligocene of Hungary is the first unequivocal fossil record of the genus, which is distinguished in the fossil record on the basis of the presence of a meral blade and meral hook on the major cheliped.Lepidophthalmusis today known exclusively from shallow-water environments. The finding of a deep-water fossil representative ofLepidophthalmustherefore appears to be a reverse of the common pattern of groups shifting environments from onshore to offshore over geological time, as seen in many taxa. The presence ofLepidophthalmus crateriferuscomb. nov. in the Kiscell Clay therefore suggests different ecological requirements for at least some populations of this genus in the geological past.
authors.affiliation: [ hyzny.matus@gmail.com ], Department of Geology and Palaeontology, Natural History Museum, Burgring 7, Vienna 1010, Austria; Department of Geology and Palaeontology, Faculty of Natural Sciences, Comenius University, Mlynská dolina G1, Bratislava 842 15, Slovakia.
authors.forename: Matúš
authors.initials: M
authors.lastname: Hyžný
authors.affiliation: [ dulai@nhmus.hu ], Department of Palaeontology and Geology, Hungarian Natural History Museum, Ludovika tér 2, Budapest H-1088, Hungary.
authors.forename: Alfréd
authors.initials: A
authors.lastname: Dulai
keywords: Callianassidae; Ctenocheles; Ctenochelidae; Decapoda; Hungary; Lepidophthalmus; Oligocene; deep-water environment; systematics