New Miocene Mexican amber ant (Formicidae, Myrmicinae) of the genus Pheidole Westwood, 1839

Abstract

ABSTRACT The genus Pheidole Westwood, 1839 is considered the most species-diverse group of extant ants in the World. A new fossil species of ant Pheidole chaan sp. nov. (Formicidae, Myrmicinae) based on one worker and one soldier is described and illustrated from the Miocene of México. The type material comprises a syninclusion from Simojovel, Chiapas, México, providing the elements to recognise the new species through morphological characters of soldier and worker castes. Pheidole chaan sp. nov. is characterised by the following combination of characters: Soldier. Head longitudinally striated; median impression area between vertex of head and posterior margin of clypeus, close to the frontal carenas; dorsal surface of mandibles smooth, lateral surface of mandibles longitudinally striated; internal margin of scapes sinuous; propodeal spines well-developed with basal area as width as tall. Worker: vertex of head concave; entire head with coarse punctures; compound eyes protruding laterally from margin of head; mesonotal groove deep, forming a U-shape concavity; petiole forming a thin triangular-shaped node. Pheidole chaan sp. nov from Miocene increases the knowledge of myrmecological biodiversity of the genus Pheidole and helps elucidate the origins and history of recent past of the clade in the New World.