First records of Geinitziidae (Insecta: Grylloblattida) from the Upper Triassic of Argentina (Mendoza)

Abstract

The salle Grylloblattidae or Grylloblattodea order (extant representatives are referred to as ‘living fossils’ and have relictual distributions) is one of the least diverse extant insect groups (with 29 species and five genera grouped into the single extant family Grylloblattidae; Jarvis & Whiting 2006). More than 44 families have been described from the fossil record, which extends back to the early Late Carboniferous (Storozhenko 1992, 1997, Vrsansky et al. 2001). During the Permian, grylloblattids were the most abundant and diverse insect group and were the ancestral stock of all other perlideans (stoneflies, webspinners and earwigs; Rasnitsyn & Quickle 2002). By the end of the Early Permian to the beginning of the Middle Permian they reached their heyday (Aristov 2005). However, the diversity of the order decreased at the end of the Middle to Late Permian. Four of the 11 Late Permian families became extinct during this interval, resulting in a minimum diversity during the Early Triassic (Aristov et al. 2009). However, some Permian families reappeared in the Middle to Late Triassic indicating the existence of Early Triassic ghost lineages