Araripus crassitibialis sp. nov. Carmo and Sampronha

Figs 5, 6

Examined material.

Holotype female: GP1e/8751 NE Brazil, Crato Formation, Aptian, Lower Cretaceous.

Preservation.

Preserved in dorsal view. Frons and occiput visible. Scutellum, notopleuron, one halter, foreleg preserved. Wings partially preserved. Tergites I-VII, tergite X and cercus visible.

Diagnosis.

The same as the genus.

Description.

Holotype female. Length 23.5 mm, wing 15.5 mm. - Head: hemispherical, narrower than thorax; scape oval, nearly as wide as long; frons appears divergent above; frontal callus absent; apparent callosity visible near the vertex; subcallus not inflated or pronounced; notopleuron robust and well developed. - Thorax: scutum and scutellum visible, the former much longer than wide. - Legs: fore tibia inflated. - Wings: vein Sc very long, inserting in C very close to R1, with few visible setae; pterostigma small, barely visible; R2+3 very sinuous, inserting in C parallel to R4 and forming a 90° angle; vein R4 strongly angled and without an appendix; cell r5 open; vein M1 sub-parallel to M2; M3 diverging from M2; vein r-m inclined towards wing base; m-cu inserted very close to the origin of R4; wing ca. 3 times longer than wide. - Abdomen: nearly twice the length of the thorax. - Terminalia: Tergite X appears to be undivided; cercus two-segmented.

Etymology.

From latin, crassus (tick) + tibia (leg), in reference to the enlarged tibia.

Comments.

The inflated tibia is present in several species from different tabanid genera, especially in the Chrysopsinae and Tabaninae subfamilies ( Coscarón and Papavero 2009a), but had not been previously recorded for Cretaceous species. As in Cratotabanus, the female terminalia in Araripus gen. nov. has a two-segmented cercus. This is absent from every extant horse flies; in fact, the presence of a one-segmented cercus is synapomorphy of a clade formed by Athericidae + Tabanidae (Yeates 2002).