Oldest known pteroplistine cricket and other Gryllidae (Orthoptera) from the paleogene Fur and Olst formations of Denmark

The present paper reports on a study of 16 fossil specimens of Gryllidae fr om the Paleogene marine sediments of the Fur and Olist Formations (Paleocen e/Eocene) of Denmark. The oldest known Pteroplistinae, Pteroplistus danicus sp. n., is described on the basis of 2 isolated male forewings. Additional material consists of isolated male and female forewings, several almost co mplete female specimens, and large body fragments. The systematic position of these specimens, however, is unclear, because diagnostic characters are not preserved. Possible synapo-morphic characters of the wing venation shar ed by P. danicus sp. n., the second known fossil species of Pteroplistinae Eneopterotrypus chopardi Zeuner from the Eocene, and extant Pteroplistinae are proposed. Most of the fossil crickets derive from the Paleocene Olist F ormation. Pteroplistinae are poor flyers, thus their presence suggests near shore conditions of the former marine environment, which is confirmed by a nalysis of the fish fauna and other insect groups. The present geographical restriction of the Pteroplistinae to India, Vietnam, and Malaysia is presu mably a consequence of climatic changes during the Cenozoic.