Abstract

Polychelidan lobsters (Decapoda: Polychelida) are crustaceans with extant species which are restricted to deep water environments. Fossil species, however, used to live in more varied palaeoenvironments, from shallow water to deep water, and were more diverse morphologically. We redescribe two species of polychelidan lobsters, the Late Triassic Rosenfeldia triasica Garassino, Teruzzi & Dalla Vecchia, 1996 and the Late Jurassic Eryon oppeli Woodward, 1866, recently assigned to the same genus, Rosenfeldia, based upon only a few characters. Our investigation of all available material of both species leads us to distinguish these two species and to erect Rogeryon gen. nov. to accommodate Eryon oppeli. The palaeobiology of both species is interpreted for the first time. Rosenfeldia triasica with its stout first pereiopods and mandibles with both incisor and molar processes (documented for the first time in Polychelida) was benthic and probably fed either on slow-moving sedentary preys or was a scavenger. Rogeryon oppeli gen. et comb. nov. was benthic, visually adapted to shallow water palaeoenvironments, and possibly had a diet similar to that of slipper lobsters and horseshoe crabs. The redescription of these two species highlights the palaeobiological diversity of fossil polychelidans.

Highlights

  • IntroductionPolychelidans are recognizable by their four to five pairs of chelate pereiopods (“walking limbs” = thoracopods 4–8, Galil 2000)

  • Polychelidan lobsters are an unusual group of decapod crustaceans: they were first discovered fossilized in the famous Solnhofen-type outcrops of the Upper Jurassic of southern Germany (Desmarest 1817) long before being discovered in modern deep-sea environments (Heller 1862).Polychelidans are recognizable by their four to five pairs of chelate pereiopods (“walking limbs” = thoracopods 4–8, Galil 2000)

  • Polychelidan lobsters (Decapoda: Polychelida) are crustaceans with extant species which are restricted to deep water environments

Read more

Summary

Introduction

Polychelidans are recognizable by their four to five pairs of chelate pereiopods (“walking limbs” = thoracopods 4–8, Galil 2000) They are characterized by a complete reduction of the rostrum, replaced by a frontal margin, and by their dorsoventrally flattened carapace or cephalothorax shield (cylindrical or laterally flattened in most other decapods). The present study aims at redescribing one of the most peculiar of fossil polychelidan lobsters: Eryon oppeli Woodward, 1866, from the famous Solnhofen-type lithographic limestones of southern Germany. This species was recently assigned to Rosenfeldia Garassino, Teruzzi & Dalla Vecchia, 1996 by Garassino & Schweigert (2006). A careful examination reveals that it bears little resemblance to the type species Rosenfeldia triasica Garassino, Teruzzi & Dalla Vecchia, 1996

Methods
Results
Discussion
Conclusion
Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call