A PLANT HOPPER (NOGODINIDAE) FROM THE UPPER PALAEOCENE OF ARGENTINA: SYSTEMATICS AND TAPHONOMY

: A new taxon of plant hopper, Celinapterixini, is erected based on Celinapterix bellissima gen. et sp. nov. from the Upper Palaeocene Maíz Gordo Formation, north‐west Argentina. Its phylogenetic relationships within the Fulgoroidea and Nogodinidae are discussed. The Danish Eocene species Hammapterix paucistrata (Henriksen) is transferred to the Nogodinidae and placed in a new genus, Henriksenopterix, based on wing‐venation characters. The new plant hopper is an unusual case of articulated preservation from the Maíz Gordo Formation. The palaeoenvironment is interpreted as a carbonate mudflat subenvironment with a low flow of energy, created during a period of contraction of the lacustrine system. The plant hopper is considered to have sunk and been buried in a soupy substrate. Early fossil‐diagenesis seems to have occurred over an extended period of time, because although the specimen preserves all original soft‐body parts, these occur as an amorphous mass owing to tissue decomposition. The occurrence of three‐dimensional preservation suggests the absence of fossil‐diagenetic compression; the sediments seem to preserve more‐or‐less their original thickness.