First Eumastacoidea and new Locustopsidae (Orthoptera: Caelifera) from the Crato Formation of Brazil

The first genus and species of Eumastacoidea from the Lower Cretaceous Crato Formation of northeastern Brazil is described. Cratomastax mariellaae gen. et sp. nov. is reported from a relatively well-preserved specimen, with the wings, head, and metathoracic leg aspects in good condition. It is assigned to the Eumastacoidea based on its forewing venation feature, with M and CuA + CuPaα fused.

Due to the presence of two branches of M + CuA, it may be allied to Chorotypidae, but the forewing venation of other families of Eumastacoidea is not sufficiently known to confidently exclude it from these taxa. Additionally, a second species of Aestuacrida is described from the Crato Formation. Aestuacrida mikronaulion sp. nov. is significantly larger than A. stereofemoris Schall, Lima, Heads, Pinheiro, Kotthoff & Husemann, 2025, and its wing venation is more fully preserved.

The new species suggests that Aestuacrida belongs to the subfamily Pseudoacridinae, increasing the diversity of this recently established taxon. Lastly, a new specimen of Locustrix gallegoi Martins-Neto, 2003, is reported. Individuals of this genus appear to be rather rare, and the apomorphies of Locustrix Martins-Neto, 2003, were not well understood.

The new specimen helps resolve this issue. Locustrix can now be assigned to the subfamily Locustopsinae. The genus is characterized by having two branches of M and CuA + CuPaα and a short ScP of only about 50 % of the total forewing length.