RHAGIONEMESTRIIDAE, Ussatchov, 1968

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 : 55

FAMILY RHAGIONEMESTRIIDAE

This is a small extinct family from the Late Jurassic to Early Cretaceous, comprised of six genera and nine species. Proposals are not supported here that the unusual living genera Exeretonevra and Heterostomus be placed in this family (e.g., Mostovksi and Martínez-Delclòs, 2000; Nel, 2010), or conversely, that Rhagionemestriidae should be placed in Xylophagidae ( Jarzembowski and Mostovski, 2000) . Exeretonevra larvae indicate that this genus is in the Xylophagidae ( Palmer and Yeates, 2000) , a placement confirmed by molecular evidence ( Wiegmann et al., 2011). Heterostomus appear to be in the Tabanomorpha based on adult and pupal morphology (Coscarón et al., 2013). Lastly, the discovery of a species of rhagionemestriid in Burmese amber, described below, indicates a relationship distant from Xylophagidae .

Critical structures of Jurassinemestrinus eurekus , n. sp., reveal that this family is without question closely related to Acroceridae . This is based on the following synapomorphies: hemispherical head comprised mostly of the eyes; hind margin of eye with slight emargination, fine transverse line through middle of eye; antenna small, with simple, stylate terminal article, reduced number of antennal articles (1-segmented in Acroceridae , 2-segmented in J. eurekus ); tergal mounds (found in some but not all Acroceridae ); wing membrane glassy (devoid of microtrichia), and wrinkled; distinctive lack of a transverse scutal suture; and structure of the male genitalia.

There are four genera and four species of Late Jurassic Rhagionemestriidae , all from Central Asia and China (fig. 20): Rhagionemestrius rapidus Ussatochov (Karbastau Formation, Kazakhstan), Nagatomukha karabas Mostovski and Martínez-Delclòs (2000) , Sinonemestrius tuanwangensis Hong and Wang (Laiyang, China), Jurassinemestrinus orientalis J.-F. Zhang (Dao- hughou Formation, Inner Mongolia, China) ( Ussatchov, 1968; Mostovski and Martínez-Delclòs, 2000; J.-F. Zhang, 2010). Early Cretaceous Rhagionemestriidae include Iberomusca kakoeima Mostovski and Martínez-Delclòs and I. ponomarenkoi Mostovski and Martínez-Delclòs, 2000 (Las Hoyas Formation, Spain), Sinonemestrius akirai Jarzembowski and Mostovski (Weald Clay, England), Sinomusca mostovskii Nel (Yixian Formation, China), and the species in Burmese amber (herein). The group was widespread in eastern Laurasia in the Late Mesozoic.