Gabaleryon, a new genus of widespread early Toarcian polychelidan lobsters

Polychelidan lobsters are decapod crustaceans with a unique anatomy: a dorsoventrally flattened carapace, four to five pairs of chelate appendages and a completely reduced rostrum. These crustaceans, like most other malacostracans, are mostly preserved in outcrops in which exceptional preservation occurs, Fossil-Konservat-Lagerstatten. Unfortunately, Lagerstatten are rare, and therefore disjointed both geographically and stratigraphically. This study focuses on a new genus of polychelidan lobster, Gabaleryon gen. nov., with the description of two new Toarcian species, Gabaleryon coquelae sp. nov. from France and G. garassinoi sp. nov. from Italy. The long-standing question of the generic assignment of Eryon moorei (Toarcian, UK) is resolved and the species is ascribed to Gabaleryon. The occurrences of these three species and a fourth, Gabaleryon sp. 1 (Toarcian, Germany), provide a first palaeobiogeographical indication that the Fossil-Lagerstatten in which they occur were linked during Toarcian times. The occurrence of a possible fifth species of Gabaleryon in the late Bajocian–early Bathonian of France may extend the stratigraphical distribution of the new genus. Finally, these new species increase our knowledge of fossil polychelidans and place the Toarcian as their second peak of palaeobiodiversity, after that at the Kimmeridgian–Tithonian boundary. http://zoobank.org/urn:lsid:zoobank.org:pub:073513BD-A0D8-4A5B-B9DE-1C61781077DC © 2016 The Trustees of the Natural History Museum, London 2016. All Rights Reserved