First fossil harvestmen (Arachnida: Opiliones) from Spain and notes on the fossil record of opiliones

Abstract

The first two harvestmen (Arachnida: Opiliones) from the fossil record of Spain are reported herein. The first one is an imperfect specimen from the Early Cretaceous (Barremian) laminated limestones of Las Hoyas (Province of Cuenca). The second one is a complete, finely-preserved specimen from the Early Miocene (Burdigalian) lacustrine oil-shales of the Rubielos de Mora Basin (Province of Teruel). Both sites are Konser-vat-Lagerstätten that have a rich fossil record of numerous plant and animal groups. The Barremian specimen is considered here as Opiliones indet. because the poor state of preservation does not allow identification of diagnostic characters at subordinal level. The Miocene specimen is a new species of the extant genus Cosmobunus (Sclerosomati-dae), C. sagani nov. sp., diagnosed by its unique set of cuticle sculpturing within the genus. A review of the scarce fossil record of the group and some general taphonomic factors that may explain such scarcity are provided as well.