Prophora dimorion Grimaldi 2018, new species
Creators: name: Grimaldi, David A.
Publisher: name: Zenodo
Year: 2018
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Phoridae
Prophora
Prophora dimorion

description: Prophora dimorion, new species
Figures 17, 47C, 48
DIAGNOSIS: As for genus, by monotypy.
DESCRIPTION: Based on both sexes. Body length 1.8 mm; setae not feathered. Head: Eyes large, well separated even in male, occupying entire lateral portions of head; bare, no differentiation of facets; margins entire. Frons: Parallel sided, with well-developed median sulcus. Frontal setae: 1 large pair of fronto-orbital setae in both sexes, midway between interfrontals and verticals; 1 large pair of reclinate interfrontals in male, 3 pairs in female (anterior two pairs smaller); 1 large pair of vertical setae in male (2 pairs in female); 1 large pair of upright ocellar setae (sockets in middle of triangle) in both sexes; postocellars ca. 0.65× length of ocellars, slightly divergent. No vibrissa. Occiput near posterior margin of eye with row of fine setae, decreasing in size ventrad. Antenna: Scape very thin, ringlike; pedicel small, conical, inserted into basal flagellomere on mesal surface of flagellomere; basal flagellomere small, short ovoid; arista dorsally situated, 3-articled, basal 2 articles very short; terminal article of arista long (greater than width of head), micropubescent. Mouthparts not fully observable. Thorax: Short, stout, dorsum gently to moderately arched. Proscutellum present, well developed, lenticular, prosternum large, exposed, bare. Setae: 1 central row of ca. 10 long, fine acrostichals; row of similar setae on each side of acrostichals, anterior to dorsocentrals, shorter row lateral to these; all setae in rows decreasing in length anteriad. One large pair of dorsocentrals present; 1 large supraalar; 1 large postalar; 1 large postpronotal; row of 4 large, presutural notopleurals; 2 pairs of large scutellars (apical pair slightly longer). Pleuron without setae. Wing: Very similar in shape and vein proportions to Hennigophora robusta; membrane with microtrichia at posterior margin only. C with short spinules, widely spaced (distance between each greater than length of spinule). Tegula with row 4 strong setae on posterior margin, basicosta with 4 setae; details of wing base with poor visibility due to preservation (e.g., development of M stem, basal cells). R 4+5 relatively short; anal lobe relatively well developed (as in Hennigophora); alular setae long, not feathered. Legs: All pretarsi with empodium either absent or so reduced as to be unobservable at 200×; tarsomeres 1–4 with setulae in longitudinal rows, hair seam on mesal surface. Foreleg: coxa with minute, fine setulae overall; row of 6 large setae on ventrodistal margin; coxa widely separated, by distance approximately equal to thickness of coxa. Femur: Stridulatum present (as seen in male holotype: 11 scalelike teeth of scraper observed on left profemur; file not observable; no large setae on profemur. Protibia without large setae. Mid- and hindlegs: coxa with several large setae on posterior margin; femur without large setae; tibia with 1 large ventroapical seta, several smaller ones partially encircling tibial apex. Abdomen: Tergites well developed in both sexes; at least 3–4 large anterior sternites present in male (more posterior ones obscured), female with all but two terminal sternites (7 and 8) lost. Male Terminalia: Epandrium exposed, well developed, with ventral lobe (has broad attachment); surstylus articulating with lobes (not fused), clavate, pendulous. Ventral epandrial lobes, surstyli, periphallic appendages asymmetrical. Female Terminalia: Largely obscured; abdominal segments 7 and 8 much smaller than anterior ones, terminalia do not appear telescoped; hypoproct well developed.
SPECIMENS EXAMINED: Holotype, male, AMNH Bu8783; paratype, female, JZC Bu242, both in Burmese amber, well preserved, complete.
ETYMOLOGY: From Greek, di- (“two”) and morion (“parts” in genitive plural) in reference to sexual dimorphism of the head setation.
COMMENTS: Differences between the holotype male and paratype female are attributed to sexual dimorphism, otherwise the two specimens are very similar: body size and proportions, identical setation of the thorax, proportions of the wing veins, even the widely spaced costal spinules. Differences are the frontal setation, with the female having 2 additional pairs of small interfrontals (vs. 1 pair in the male), and a pair of inner verticals. Also, the female has only two small sternites (7 and 8); the male has well developed ones. Head setation is sexually dimorphic in living sciadocerines; likewise for the development of abdominal sternites in some basal Euphorida.
description: Published as part of Grimaldi, David A., 2018, Basal Cyclorrhapha In Amber From The Cretaceous And Tertiary (Insecta: Diptera), And Their Relationships: Brachycera In Cretaceous Amber Part Ix David A. Grimaldi, pp. 1-97 in Bulletin of the American Museum of Natural History 2018 (423) on pages 1-97, DOI: 10.1206/0003-0090-423.1.1, http://zenodo.org/record/4613008