Eucaudomyia, Grimaldi, 2016

Grimaldi, David A., 2016, Diverse Orthorrhaphan Flies (Insecta: Diptera: Brachycera) In Amber From The Cretaceous Of Myanmar: Brachycera In Cretaceous Amber, Part Vii David A. Grimaldi, Bulletin of the American Museum of Natural History 2016 (408), pp. 1-132 : 85-86

Eucaudomyia , new genus

TYPE SPECIES: Eucadomyia longicerci n. sp.

DIAGNOSIS: As for family, monogeneric.

ETYMOLOGY: Eu - (Greek, “well”), cauda (Latin, “tail, appendage”), myia (Greek, “fly”), the “well-tailed fly,” in reference to the unique oviscapt and how it contrasts with the short, broad body. The gender of the name is feminine.

COMMENTS: This taxon could possibly be placed in Archisargoidea , but the antennae are inserted frontally (vs. dorsally in Archisargoidea ), and the venation is too reduced to discern homologies with typical archisargoids. Like archisargoids, Eucaudomyia have a subspherical head with large eyes; no macrosetae on the body or tibial spines; a small antenna with a 1-articled postpedicel; and cerci that are modified into an oviscapt. The oviscapt in typical archisargoids, however, has a bulbous base and is abruptly narrowed to a sharp tip; in Eucaudomyia the cerci are long, valvelike structures dorsally closed by a long epiproct, the apex not particularly sharp.

Eucaudomyia have some features in common with Tethepomyiidae , especially Tethepomyia : large eyes; a pair of incomplete, paramedian longitudinal furrows on the mesonotum; short, consolidated tarsi (including the basitarsomeres), vestigial mouthparts (where observable, though these are less reduced in Tethepomyia ), the reduced venation, and structure of the oviscapt (the female of Tethepomima is unknown). In both groups all longitudinal veins are apically evanescent (except in Tethepomima ); veins R 1 and Rs are thick and sclerotized, but simple (unbranched) in Tethepomyia and Eucaudomyia (2-branched in Tethepomima ); vein M is simple in all three genera; veins CuA, CuP, and A are present. Tethepomyia zigrasi has a reduced anal lobe, like Eucaudomyia , though the other three species of tethepomyiids have a well-developed anal lobe. Another difference between tethepomyiids and Eucaudomyia is vein CuA with an apical fork in the former (though not visible for T. thauma ).

The only tethepomyiid where the female is known is Tethepomyia zigrasi (fig. 52). Its oviscapt is a pointed, grasping structure that is curved ventrally (fig. 52C), but there are some modifications in common with Eucaudomyia . Both species have abdominal segment VII modified into a funnellike shape, and segment VIII (called “syntergosternite VIII” for Tethepomyia in Grimaldi et al., 2011) is tubular. The apical segment of the oviscapt in T. zigrasi was interpreted as “syntergosternite IX” in Grimaldi et al. (2011), but this structure is probably comprised of the fused cerci (unfused but elongate in Eucaudomyia ). Tethepomyia were probably para- sitoids ( Grimaldi et al., 2011), but the structure of Eucaudomyia ’s oviscapt indicates this species probably was not a parasitoid. In Eucaudomyia the cerci are not particularly sharp, sclerotized, or needle shaped. It may have oviposited into soil or in crevices in bark.