A new Cretaceous orthopteran family of the Caelifera (order: Orthoptera) from Burmese amber of northern Myanmar

Abstract A new family of short horned grasshoppers, Burmecaelidae fam. nov., is described on the basis of a new species: Burmecaelinus armis fam., gen. et sp. nov. While any extant species can clearly be sorted into the Tridactylidea and Acrididea, the new fossil species presented here does not clearly match any of the two groups. The metafemora of the new family are apparently saltatorial and greatly inflated along its entire length, which is similar to extant and Mesozoic Tridactylidae and Ripipterygidae. In contrast, the compound eyes are elongated and protrude from the head dorsally; the elongated area of the pronotum does not cover the abdomen. Although the morphology of the hind legs is shared with Tridactyloidea, the shape of the head and abdomen are more similar to Tetrigoidea and Eumastacoidea. We suggest two hypotheses: (1) the new family emerged at the basis of the superfamilies Tridactyloidea and Acridoidea early in Caeliferan evolution, or alternatively (2) the new family emerged within Tridactyloidea, between the families Tridactylidae and Ripipterygidae. The new family may have emerged when these families split. The phylogenetic placement of the new family needs to be further evaluated in the future based on more specimens.