Insects from Lower Miocene of Ribesalbes (Castellón, Spain). Paleoptera and Neoptera poli- and paraneoptera

The Ribesalbes Lower Miocene fossil insects site (Castellón, Spain) is located in the Ribesalbes-Alcora basin (Iberian Range). This basin is a complex graben limited by normal faults. The fossil insects appear in oil shales which were formed from the sediments of a meromictic stratified lake. Bioturbation has not been observed but tectonic deformations are frequent. Both the extraordinary fossil preservation and the strong lamination of the sediments, suggest the action of algal or microbial mats. Apart from insects, other fossil remains have been found: Anura and Urodela amphibians, bird feathers, Gastropoda, Ostracoda and a high number of leaves, flowers and seeds. The study of the numerous specimens housed in Museo Paleontológico Municipal de Valencia, Museo del Colegio 'La Salle' de Paterna (Valencia), Museo Nacional de Ciencias Naturales (Madrid) as well as in private collections, has resulted in the identification of a high number of taxa not cited before in Ribesalbes (8 orders and 23 families). In this paper, the following orders are studied: Odonata, Grylloptera, Orthoptera, Isoptera, Psocoptera, Homoptera, Heteroptera and Thysanoptera. Two new fossil species of dragonfly and damselflies are described, Oligaeschna saurai n. sp. (Aeshnidae) and Sympecma? ribesalbesensis n. sp. (Lestidae). The species Platycnemis? cincuneguii Gil, 1926, is redescribed. Isoptera, Orthoptera and Psocoptera fossil records from Ribesalbes provide new evidences which support the existence of a warm climate in this geographical area during the Lower Miocene.

Key words: Insecta, Paleoptera, Neoptera, Lacustrine environment, Lower Miocene, Spain.