Rajpardia grimaldii Bickel, 2022

BICKEL, DANIEL J., MARTIN, JOHN, AGNIHOTRI, PRIYA & SINGH, HUKAM, 2022, Dolichopodidae (Diptera) from the Eocene amber deposits of Cambay and Kutch Basins, India, Palaeoentomology 5 (5), pp. 475-486 : 483

Rajpardia grimaldii Bickel sp. nov.

( Fig. 4D, F )

Type material. Holotype: ♂, INDIA: Gujarat: Tadkeshwar Lignite Mine, Lower Eocene strata of the Cambay Shale Formation , 21°21.400′N, 73°4.532′E, 17–22/I/2009. D. Grimaldi & P. Nascimbene, Tad-372 ( AMNH).

Etymology. This species is named in honour of David Grimaldi, who has contributed so much to the revitalization of palaeoentomology, a field previously in a somewhat moribund state. His many papers and books on fossil faunas across a wide spectrum of taxa coupled with his excellent line drawings have brought a freshness to the study of insect evolution. We are pleased to contribute to this Festschrift, as one of us (D.J.B.) had promised him this paper several years ago, so this previously halffinished manuscript is now finally complete.

Diagnosis. As for genus.

Locality and horizon. Cambay and Kutch basins, Gujarat State, India; Eocene.

Description. Male: length: 1.0 mm; wings obscured ( Fig. 4D, F ); part of head and most of thorax missing on left side ( Fig. 4D ).

Head. Wider than high;dorsal postcranium apparently concave; vertex, frons and associated setation missing; eye facets uniform; clypeus conformable with eye, not projecting anteriorly; palp and proboscis brown; antenna brown; scape and pedicel short; postpedicel reniform, and partially enclosing distal pedicel; arista apical and as long as head height

Thorax. Dorsally destroyed.

Legs. Coxae and legs brown; vestiture black; CI with short anterolateral setae; CII with short anterior setae; I: 1.9; 1.6; 0.9/ 0.3/ 0.2/ 0.2/ 0.3; FI with weak subapical pv seta; TI with distinct row of 3 short ad setae along distal third and some short apicoventral setae; II: 2.1; 2.2; distal tarsomeres obscured; FII with anterior preapical seta at 4/5; other podomeres II obscured; III: 2.3; 2.9; distal tarsomeres obscured; FIII with distinct anterior preapical seta at 4/5; TIII with short dorsal ventral and ad setae.

Wings. Left wing missing, right wing bent and obscured; halter club dark brown.

Abdomen. Brown; segment 7 as short peduncle; sternite 8 comprising setose cap over hypopygial foramen, hypopygium ( Fig. 3E ) dark brown; epandrium rounded subrectangular; hypandrium developed as rounded hood; surstylus short, simple and triangular; cercus digitiform with curved apical toothlike seta.

Female. Unknown.

Remarks. Rajpardia grimaldii is known from a single damaged specimen surrounded by bubbles of apparent gaseous and liquid inclusions. Although the wings are missing and the thorax is mostly destroyed, the legs, antenna, and male postabdomen are clearly visible, making this specimen worth describing. The species has strong similarities to the Medeterinae , with its pedunculate hypopygium, lobate surstylus, simple cercus, concave dorsal postcranium, reniform postpedicel, and over all habitus. However, the presence of anterior preapical setae on femora II and III seems to preclude this placement.

Unplaced specimens

The specimen in Fig. 2B appears to be a male and has broad wings, with veins R 4+5 and M 1 widely separated, and even slightly diverging distally. The male specimen in Fig. 2D–E is distorted, with setose tibiae and external male postabdomen, and its placement is unclear.

The species in Fig. 5A and B is intriguing, and tempting to describe, but we decided not to. It is missing its head and both hindlegs, and the male postabdomen is rotated and twisted 180°, such that interpretation and a clear view of the hypopygium is impossible. Curiously, the flow of resin before solidification appears to have twisted the legs, torn off both hind legs, but left the wings rather untouched. Tibia II has a strong curved seta anterior seta at ¼. Possibly more complete specimens of this species will be discovered in the future.

Figures

FIGURE 2. Dolichopodidae undetermined. A, Left dorsal (GIAM-015). Dolichopodidae undetermined. B, Male habitus, left dorsal (GIAM-008); Dolichopodidae: Diaphorinae, nr Chrysotus. C, Female head and thorax, anterior (GIAM-009). D, Right ventral (GIAM-009); Dolichopodidae undetermined. E, Male habitus, left lateral (GIAM-019). F, Hind legs and postabdomen (GIAM-019).

FIGURE 3. Palaeomedeterus cambayensis sp. nov. A, Male habitus, left lateral, (GIAM-012). B, Male postabdomen, left lateral (GIAM-012). C, Male postabdomen, left lateral (GIAM-014). D, Male habitus, dorsal (GIAM-011). E, Palaeomedeterus ignavus (Meunier), Baltic amber: male habitus, left lateral. (Photo from the collection of Jonas Damzen, Vilnius, Lithuania. Legend: cer, cercus; st4, sternite 4.

FIGURE 4. Gujaratmyia rotunda sp. nov. A, Male habitus, left lateral (GIAM-002). B, Male habitus, right lateral (GIAM-002). C, Male wing dorsal (GIAM-002). Rajpardia grimaldii sp. nov. D, Male habitus, left lateral (GIAM-013). E, Male postabdomen, left lateral (GIAM-013). F, male habitus, right ventral (GIAM-013). Dolichopodidae: Medeterinae. G, Male habitus, left dorsal

FIGURE 5. Dolichopodidae undetermined. A, Right lateral habitus (GIAM-007). B, Wing and male postabdomen, right lateral (GIAM-007). Legend: cer, cercus; ph, phallus; st8, sternite 8; sur, surstylus; LI, LII, left legs I and II; RI, RII, right legs I and II.