Rare fossil polychelid lobsters in turbiditic palaeoenvironments

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Polychelidan lobsters are one of the rare groups of decapod crustaceans which were first discovered as fossils long before being identified in extant deep-sea environments. As for other decapods, their fossil record is highly incomplete, which complicates the reconstruction of their evolutionary history. Another problem that hinders better knowledge of the group is familial assignments, which can be difficult in the absence of a complete revision of known fossil taxa. As a result, only three fossil Polychelidae have been identified to date, the oldest dating back to the Callovian (Middle Jurassic). In the present study, we consider two rarely studied species, Palaeopolycheles crymensis Levitski, 1974 from the Toarcian–Aalenian (Early–Middle Jurassic) of Crimea (Ukraine), and Eryon neocomiensis Woodward, 1881 from the Valanginian (Early Cretaceous) of the Outer Carpathians (Czech Republic). Our reinvestigations indicate they present several characters typical of Polychelidae, and are actually morphologically quite similar to extant species, notably in the structure of the anterior part of the carapace and the small ocular incisions. Two new genera are erected to accommodate them: Tauricheles gen. nov. (type species Palaeopolycheles crymensis) and Woodwardicheles gen. nov. (type species Eryon neocomiensis). The reinvestigations show that: (1) the evolutionary history of Polychelidae is much older than previously considered; (2) Polychelidae have inhabited deep water for a long time; (3) both species are probably autochthonous or parautochthonous to turbiditic palaeoenvironments; (4) Woodwardicheles neocomiensis comb. nov. is one of the rare benthic macrofossils of the Silesian Basin.http://zoobank.org/urn:lsid:zoobank.org:pub:CE6FEEA7-4162-4AE2-9413-11FD38FE04B9