Schlingeromyia Grimaldi & Hauser

Grimaldi, David A., Arillo, Antonio, Cumming, Jeffrey M. & Hauser, Martin, 2011, Brachyceran Diptera (Insecta) in Cretaceous ambers, Part IV, Significant New Orthorrhaphous Taxa, ZooKeys 148, pp. 293-332 : 304-305

Schlingeromyia Grimaldi & Hauser gen. n.

Diagnosis.

A minute, distinctive acrocerid with medial margins of male eyes contiguous above and below antennae, hind and ventral margins of eye strongly emarginate; antennae minute, in middle of head; proboscis vestigial; eyes bare, thorax with very sparse, fine setulae; postpronotal lobes of moderate size, slightly protruding; abdomen devoid of microtrichia and glabrous (possibly reflective). Mediolobus (i.e., "pulvilliform empodium") and pulvilli pad-like. Venation distinct: All veins sclerotized, none faint; C ends at apex of R4+5; Sc short; R1 and Rs fork at ca. 0.4 × length of wing; cells br and bm continuous, not bissected (vein M extremely faint or lost from this area); two closed radial cells (r4+5 and d), plus cell m3 present; R4+5 ends near apex of wing, without an apical fork of R4-R5 encompassing apex of wing.

Type species.

Schlingeromyia minuta , sp. n., by present designation.

Etymology.

Patronym in honor of Evert Schlinger, Emeritus Professor of entomology at the University of California, Berkeley, who has devoted his career to the study of Acroceridae and who also has been a very generous patron of systematic entomology. Feminine, following the Greek myia, for fly.

Discussion.

This is a very distinctive, minute acrocerid - in body size quite the opposite of its generic namesake - which is unique for the venation, genitalia, and virtually bare body. Most acrocerids have long, fine pile on the thorax and abdomen, and many have it on the eyes and calypters. Vein Sc is very short in the fossil, and cells br and bm are contiguous. In addition, apparent retention of freely articulated gonostyli in the male genitalia appears to be a significant feature of the genus, since loss of articulated gonostyli through fusion with the gonocoxites is considered an apomorphy of the remainder of the family ( Sinclair et al. 1994). The broad, pad-like structure between the pulvilli, called the empodium in homeodactylous flies, is actually a median outgrowth of the pulvilli as based on the detailed but overlooked work of Röder (1986). The true empodium is a bristle-like distal extension of the unguitractor plate. Thus, we are calling the pad-like empodium a mediolobus. Presence of a true (setiform) empodium is considered a synapomorphy of the Heterodactyla (Woodly 1989; Yeates 2002).

Winterton et al. (2007) recently analyzed acrocerid relationships based on sequences, and concluded that the subfamily Acrocerinae is diphyletic, and the subfamilies Panopinae and Philopotinae are monophyletic. Philopotines are particularly distinctive for the hump-backed notum and postpronotal lobes that are so enlarged as to form a collar dorsally over the cervical region. Although the Baltic amber Archaeterphis hennigi superficially resembles Schlingeromyia in small body size and eye shape ( Hauser and Winterton 2007), the relatively complete venation of the latter, structure of male genitalia, and pretarsal structure indicate a much more basal position for the Burmese amber species. Relationships of Schlingeromyia to any Recent generic-group or subfamily is obscure and may reflect a stem-group position.