Tribochrysa inaequalis Scudder, 1885

Makarkin, Vladimir N., Antell, Gwen S. & Archibald, S. Bruce, 2022, A revision of Chrysopidae (Neuroptera) from the late Eocene Florissant Formation Colorado, with description of new species, Zootaxa 5133 (3), pp. 301-345 : 333-335

Tribochrysa inaequalis Scudder, 1885

Fig. 23

Tribochrysa inaequalis Scudder, 1885: 777 , Fig. 982; Scudder 1890: 169, 170; Scudder 1891: 380; Handlirsch 1906–1908 [1907]: 909; Cockerell 1908a: 90; Cockerell 1909a: 78; Carpenter 1935: 267, Fig. 6 ; Adams 1967: 232; Schlüter 1982: 260, 261; Schlüter 1984: 4; Martins-Neto & Vulcano 1989: 189, 190, Fig. 1D ; Séméria & Nel 1990: 30; Carpenter 1992: 348, Fig. 193,3; Meyer 2003: 208; Nel et al. 2005: 67; Makarkin & Archibald 2013: 143; Archibald & Makarkin 2015: 361.

Type material. Holotype MCZ 243 (Scudder’s no. 7982). A poorly-preserved articulate specimen in probably dorso-lateral aspect. Verbatim label data [typed]: (1) “Mus. Comparative Zoölogy, Cambridge / No. 243/ Tribochrysa inaequalis / Scud / Florissant Miocene”; (2) [handwritten]: “ 243 type Tribochrysa inaequalis Scud / Florissant / Neuroptera : Chrysopidae ”. The specimen has red and black ink writing on the rock that says “7982 / 243”, and a red paper label glued to the rock that says “Type.”. The specimen is covered with Canada balsam.

Type locality and horizon. USA: Colorado: Teller County: Florissant (precise collecting locality unknown); Eocene , late Priabonian ; Florissant Formation .

Diagnosis. May be distinguished from T. firmata by more closely spaced subcostal veinlets (seven between origin of RP and third ra-rp) [ T. firmata : five– six]; 10 branches of RP [ T. firmata : eight].

Redescription. Body very poorly preserved, with only one eye well discernible (ca. 0.5 mm in diameter).

Forewing ca. 12.5 mm long, ca. 4.7 wide (length to width ratio 2.66). Costal space relatively narrow. Preserved subcostal veinlets simple, widely spaced. Pterostigma, distal part of Sc, RA not discernible. RA with nine preserved crossveins (apparently ten complete). Origin of RP relatively far from wing base (at ca. 0.22 complete length). Anterior trace of RP zigzagged, with ten branches. Basal crossvein between RP, M (1r-m) rather long, connecting anterior trace of RP, MA within im at nearly proximal one-fourth length. M arched proximad fork; dividing to MA, MP distad level of origin of RP. MA, MP strongly curved; MA rather shallowly forked distad Psc; MP deeply forked at Psc. Crossvein between MA, MP (1im) rather long. Im elongate, almost not divergent distally (length/width 4.2). Psm poorly developed, strongly zigzagged. Crossvein 2m-cu very long, connecting im, CuA at nearly proximal one-ninths im length. CuA probably with three simple branches. Psc rather well developed, slightly zigzagged. CuP deeply forked. Crossvein 2icu connecting CuA, anterior branch of CuP proximad 2m-cu. CuA, A1 closely approaching for short distance. A1, A2 simple. Two gradate series of crossveins: inner series arranged in strongly broken line, with eight preserved crossveins distad MA (apparently 8–9 complete); outer series arranged in slightly curved line, with seven crossveins distad RP2 (apparently eight complete).

Hind wing very poorly preserved.

Remarks. Much of the fossil is obscured by a covering of Canada balsam, and so we are only able to describe the forewing venation.

Figures

FIGURE 1. Archaeochrysa paranervis Adams, 1967, holotype UCM 4419. Scale bar = 3 mm.

FIGURE 6. Wing venation drawings of Archaeochrysa sp., specimen NHM.I.26921. A, right forewing; B, right hind wing; C, left forewing. Veins that cannot be assigned to the right fore- or hind wings are shown by dotted lines. Scale bars = 3 mm (all to scale).

FIGURE 23. Tribochrysa inaequalis Scudder, 1885, holotype MCZ 243. A, photograph; B, proximal part of left wings; C, venation drawing of left forewing (converted to standard view, with apex to the right). Scale bars = 3 mm.