Corethrella (Corethrella) prisca Borkent and Szadziewski

Published, First, 2008, The Frog-Biting Midges of the World (Corethrellidae: Diptera), Zootaxa 1804, pp. 1-456 : 203-204

Corethrella (Corethrella) prisca Borkent and Szadziewski

Corethrella prisca Borkent and Szadziewski 1992:457 . Type-locality: Bitterfeld , Germany. Holotype ♂ (ZMHB).

DIAGNOSIS: Male adult: only fossil species of Corethrella with a dorsomedial seta on the gonocoxite and the gonostylus with a small apical peg. Female adult: unknown.

DESCRIPTION: Male adult. Habitus as in Fig. 113B. Descriptive statistics: see Tables 2–5. Head: Outline in anterior view uncertain. Number of large setae on frons between ventromedial area of ommatida uncertain. Antenna: pedicel with at least one distinctive, more elongate, stout, dorsal or dorsolateral seta; flagellomeres as in Fig. 25E, sensilla coeloconica present on at least flagellomere 1 ( Fig. 1C in Borkent and Szadziewski 1992); flagellomere 13 with well-developed apical bifurcation. Palpus ( Fig. 35 AF) with segment 3 swollen apically. Thorax: Posterior portion of dorsocentral row with 2 elongate setae situated somewhat lateral to one another. Prescutal suture uncertain. Anterior anepisternum divided diagonally by sinuous suture, dorsal portion about equal to ventral portion. Shape of posterior anepisternum uncertain. Wing ( Figs. 1A, B in Borkent and Szadziewski 1992): Apex of R 2 basal to apex of M 1. Veins (other than costa and wing margin) with only slender scales (perhaps some setae). Legs: Mostly denuded, with only slender setae, apparently lacking scales (area of patch of whip-like setae on posterior portion of hind tibia with only sockets). Presence of thick, subapical setae on tarsomeres 1–3 uncertain. Apex of foreleg fifth tarsomeres undivided, with claws slightly subapical to apical (as in Fig. 75F). Apex of midleg fifth tarsomere absent. Claws of mid-, hind leg missing. Foreclaws without inner tooth, unequal ( Fig. 1E in Borkent and Szadziewski 1992). Foreleg third tarsomere shorter than fourth tarsomere. Empodia absent. Genitalia ( Figs. 2A, B in Borkent and Szadziewski 1992): Gonocoxite gently tapering; anteromedial area with spicules similar in length to those elsewhere on gonocoxite; with well-defined dorsal row of setae, with setae equally thick, with row curving posteromedially with posteriormost seta of row positioned dorsomedially. With one dorsomedial stout seta, more or less of even thickness for most of length, tapering near apex. Gonostylus (in retracted position) evenly curved, slender, of more or less equal thickness for entire length, tapered apically; one elongate, thick subbasal seta, situated anteriorly; apical seta peg-like, short, simple. Aedeagus not visible.

Female adult and immatures. Unknown.

DISTRIBUTION: Corethrella prisca is known only from Saxonian amber (Fig. 139), dated at 44.1 million years old. This amber was previously stated to be 22 million years old but has since been discovered to be contemporaneous with Baltic amber ( Weitschat 1997).

TAXONOMIC DISCUSSION: The state of the holotype was described by Borkent and Szadziewski (1992). It was collected from a brown coal mine at Bitterfeld near Halle, Germany .

MATERIAL EXAMINED: Male adult in amber mounted in Canada Balsam between two coverslips labeled " HOLOTYPE Corethrella prisca Borkent and Szadziewski ", "Saxonian amber, Bitterfeld, Germany, Mus. Naturk. Humb. U." ( ZMHB) .

DERIVATION OF SPECIFIC EPITHET: The name prisca (of former times, ancient) refers to the fossil nature of this species.