Archaeochrysa fracta (Cockerell, 1914)

Fig. 3

Palaeochrysa fracta Cockerell, 1914: 716, Fig. 2; Carpenter 1935: 264, Fig. 7 [inadvertently transposed with Fig. 2]; Adams 1957: 71; Martins-Neto & Vulcano 1989: 189; 190.

Archaeochrysa fracta: Adams 1967: 230; Schlüter 1982: 261; Schlüter 1984: 4; Martins-Neto & Vulcano 1989: 190; Séméria & Nel 1990: 30; Willmann & Brooks 1991: Fig. 3c; Meyer 2003: 208; Nel et al. 2005: 67; Makarkin & Archibald 2013: 127, 134, 143, Figs 15.1, 15.2; Archibald & Makarkin 2015: 361, 362, 364, 366.

Type material. Holotype MCZ 4501, collected by Henry Wickham. On the reverse of the rock is a handwritten note: “ Palaeochrysa fracta Ckll. TYPE.”. The rock is 46 x 51 mm.

Type locality and horizon. USA: Colorado: Teller County: Florissant (Wilson Ranch); Eocene, late Priabonian; Florissant Formation.

Diagnosis. May be distinguished from other species of the genus by a combination of the following character states: sides (MA, MP) of im converging basally at low angle [A. paranervis, A. cockerelli sp. nov.: sides of im parallel and converging basally at steeper angle]; 2m-cu located distinctly proximad middle of im [A. profracta, A. sanikwa: slightly distad or slightly proximad middle of im]; costal margin convex through costal space [A. profracta, A. sanikwa, A. paranervis, A. creedei: not convex in middle of costal space].

Redescription. Forewing 14.3 mm long (as preserved; ca. 15.5 mm estimated complete length), 5.5 mm wide (length to width ratio ca. 2.82). Costal margin convex. Costal space relatively broad, widest at level of basal crossvein between RA, RP. Subcostal veinlets simple proximad pterostigmal region, relatively closely spaced. Pterostigma distinct, long, fuscous; incorporated veinlets poorly discernible. Distal part of Sc not discernible. Subcostal space appears broad basally, narrow distally; subcostal crossveins not detected. RA ending on margin before wing apex; five distal veinlets preserved, partially within pterostigma. RA space broad, with 21 closely spaced crossveins (one probably incomplete in life). RP originating relatively close to wing base. Anterior trace of RP slightly zigzagged, apically forked, with 14 pectinate branches, most of these once forked (RP1, RP4 simple, RP14 unknown). Basal crossvein between RP, M (1r-m) short, connecting anterior trace of RP distad basal crossvein ra-rp, within im near fork of M. M dividing to MA, MP far distad origin of RP. MA, MP zigzagged, each deeply forked at Psc. Crossvein between MA, MP (1im) long. Im elongate (length/width ratio 4.48); tapering basally. Psm poorly developed, zigzagged. Crossvein 2m-cu connected im, CuA at nearly proximal one-thirds of im. CuA probably with two simple branches. CuA continuing into well developed, only slightly zigzagged Psc, which continues into outer gradate series of crossveins. CuP deeply forked. 1icu located rather far from origin of CuP; 2icu connecting CuA, anterior branch of CuP. c1: c2 length ratio ca. 0.53:1. A1 simple. A2, A3 fragmentarily preserved. Two gradate series of crossveins nearly parallel; inner series with 13 crossveins distad MA; outer series with 12 crossveins distad RP2.