Decapod Crustacea from the Agrio Formation (Lower Cretaceous) of the Neuquén Basin, Argentina

Authors

  • BEATRIZ AGUIRRE-URRETA,

    Corresponding author
    1. Departamento de Ciencias Geológicas, Instituto de Estudios Andinos Don Pablo Groeber (UBA-CONICET), Universidad de Buenos Aires, Pabellón II, Ciudad Universitaria, 1428 Buenos Aires, Argentina; e-mail: aguirre@gl.fcen.uba.ar
      Corresponding author.
    Search for more papers by this author
  • DARÍO G. LAZO,

    1. Departamento de Ciencias Geológicas, Instituto de Estudios Andinos Don Pablo Groeber (UBA-CONICET), Universidad de Buenos Aires, Pabellón II, Ciudad Universitaria, 1428 Buenos Aires, Argentina; e-mail: aguirre@gl.fcen.uba.ar
    Search for more papers by this author
  • PETER F. RAWSON

    1. Centre for Environmental and Marine Sciences, University of Hull (Scarborough Campus), Filey Road, Scarborough YO11 3AZ, UK
    2. Department of Earth Sciences, University College London, Gower Street, London WC1E 6BT, UK
    Search for more papers by this author

Corresponding author.

Abstract

Abstract:  Two species of decapod crustacean are recorded from the Agua de la Mula Member of the Agrio Formation (Upper Hauterivian – Lower Barremian) of the Neuquén Basin of west-central Argentina, namely Astacodes falcifer Bell and a new species of Palaeohomarus, P. pacificus. The preservation of the specimens is exceptional, some showing delicate compound eyes and a stridulatory apparatus, features rarely found in fossil forms. Many specimens are preserved articulated inside calcareous nodules, within dark-grey shales. The lobster-bearing sediments accumulated in a low-energy marine environment and diagenetic mineralization occurred very rapidly, prior to significant decay, thus allowing exceptional preservation of specimens. Palaeohomarus was a rare genus in the Cretaceous with a palaeogeographic distribution restricted to the Mediterranean Tethys, the eastern USA and Madagascar, while Astacodes falcifer has been recorded only from Speeton (eastern England) and Neuquén.

Ancillary