Many undescribed species exist, especially in tropical wet forests.
The Caelifera are predominantly tropical, but most of the superfamilies are represented world wide. None the less they show considerable diversity. The Caelifera are probably the oldest living group of chewing folivorous insects. The Tettigonioidea may predate them geologically, but it is unclear how herbivorous these were, as many Tettigonioids are even now still carnivorous or omnivorous. Essentially modern Eumastacids are known from the mid-Jurassic, modern Tridactyloids and Tetrigoids from the early Cretaceous, Acridoids from the Eocene.