Cimbrophlebia flabelliformis, Archibald, Bruce, 2009

Archibald, Bruce, 2009, New Cimbrophlebiidae (Insecta: Mecoptera) from the Early Eocene at McAbee, British Columbia, Canada and Republic, Washington, USA, Zootaxa 2249, pp. 51-62 : 52-54

Cimbrophlebia flabelliformis , sp. n.

( Fig. 1 A–B)

Diagnosis. Wing distinguished from those of other Cimbrophlebia species by the following: 1), 2A morphology: four pectinate branches separates it from C. bittaciformis , [seven branches: three basal branches pectinate, four distal branches dichotomous], C. leahyi [six branches: two basal branches pectinate, minimum of four dichotomous distal branches], not known to be distinct from C. brooksi , C. westae , where 2A is little known by preservation; 2), Shape: length about four times width separates it from C. brooksi [distinctly narrower: length about five times width], C. bittaciformis [similarly slender (see remarks)], ( C. leahyi , C. westae length also about four times width); 3), Colouration distinct from that of C. brooksi , C. westae , C. bittaciformis (see below); closest to that of C. leahyi (as below) differing from C. leahyi by more overall dark colouration, including 2A region [ C. leahyi : light], further differentiated from C. leahyi by distinctly round / oval light spots [ C. leahyi : differing position, sizes of more irregularly shaped light spots], (see descriptions, remarks, Figs. 1 A; 2A, B; 4A, C; 6A, C; 7A).

Description: holotype wing. As in diagnosis, Fig. 1 A, B, and the following. Length 28 mm, width 7 mm. Colouration as in Fig. 1 A: dark, with eight light spots (possibly more in basal-most region?) four along anterior portion, basal two smaller, distal two larger; four smaller spots along posterior portion. Sc: Sc1 terminates on C ~2/3 wing length; Sc2 separates from R1 at pterostigmal region, joins with C at steep angle. R1 branched, curved around pterostigma to join C. Rs with four dichotomous branches. M with four dichotomous branches; not preserved in basal quarter of wing. Branching of Cu1, Cu2 not preserved; Cu1 long, straight, until 2/3 wing length, bent posteriad at m-cu to hind margin; Cu2 straight for preserved portion, close to Cu1, not preserved distad bend of Cu1. 1A: long, straight, close to Cu 2 in basal 2/3 of wing, apicad gently bent posteriad, meeting hind margin. 2A with four pectinate branches (second branch with crossvein to posterior margin). 3A: not detected. Few crossveins detected as preserved ( Fig. 1 B).

Type material. Holotype: UCCIPR L-18 F-763 (part), UCCIPR L-18 F-764 (counterpart). A well preserved fore- or hind wing; housed at TRU; labelled: Holotype Cimbrophlebia flabelliformis, Archibald, 2009 . Collected by unknown person at McAbee in 2002, donated to TRU by David Langevin, 2002.

Locality and age. McAbee, British Columbia, Canada; Early Eocene.

Etymology. The specific epithet flabelliformis is formed from the Latin flabellum, “fan”, and forma, “shape”, referring to the overall impression of the somewhat evenly separated wing veins, radiating apicad in a fan-like manner.

Remarks. The configuration of the basal portion of 2A seen in C. flabelliformis and C. sp. A corresponds with the vein fragment of C. bittaciformis previously identified as 3A ( Willmann, 1977: Fig. 2 ) and subsequently with uncertainty ( Willmann, 1989: Fig. 135), indicating that this similarly-placed vein on C. bittaciformis may also be a portion of 2A.

The wing of C. flabelliformis is about four times as long as wide, as is that of C. leahyi (see bottom wing in Fig. 2 C), C. westae , and apparently C. sp. A judging by the shape of its preserved portion. This is distinct from the more slender wings of C. brooksi , length / width about 4.9, and C. bittaciformis (width not reported, but these appear distinctly long and slender: see Willmann, 1977: Fig. 1 , complete wings of the holotype, and Fig. 2 , incomplete wing of the paratype). These are confidently not simply forewing / hind wing differences, as shape appears reasonably consistent between them (comparable in C. leahyi and C. bittaciformis ).

The lengths of complete (or mostly so) cimbrophlebiid wings vary from about 25 to 38 mm: C. westae ~ 25 mm; C. flabelliformis , 28 mm; C. leahyi : ~ 31 mm; C. bittaciformis , hind wing 31.5 mm and forewing 34.5 mm; C. brooksi , ~ 38 mm. These differences, however, fall within variation found in the scorpionfly Panorpa communis ( Ohm, 1961) ; further, where known, hind wings are a bit smaller than forewings. Only the great size differences between that modelled for the incomplete wing of C. sp. A (estimated as> 40 mm long) and the much smaller C. flabelliformis and C. westae are here considered meaningfully distinctive, given current knowledge.

The holotype of C. flabelliformis bears four branches of Rs, unlike those of C. leahyi , C. brooksi , and C. westae , which have five branches. Willmann (1977) found this character to be plastic within C. bittaciformis (and see P. communis: Ohm, 1961 ), and so this is not considered diagnostic here.

Wing colouration of the Okanagan Highlands species may be separated into three groups: 1), that of the McAbee species C. flabelliformis and C. leahyi ; 2), of C. brooksi (Republic) ; and 3), of C. westae (Republic) . C. flabelliformis and C. leahyi have variations of a general pattern consisting of mostly dark wing, with a series of large, irregular to oval light spots extending along the length of the anterior portion of the wing, touching the anterior margin: the smallest one or two in the basal quarter, a large one at about mid-wing, and a large one between this and the apex. There are various smaller spots along the posterior half of the wing. The preserved portion of C. sp. A indicates that it may belong to this group.

The colouration of the C. westae wing is somewhat similar to that of the McAbee species, but with more, exaggerated light regions, which extend the length of much of the posterior wing as known, and a further light band apicad the large spot in the corresponding position of the apical-most one of C. flabelliformis and C. leahyi . The resultant remaining dark colouration is arranged as a lengthwise zigzag touching the anterior, but not posterior margin ( Fig. 6 C). Much of this colour pattern is evident on regions of the wing not preserved in the single specimen of C. sp. A, which cannot be confidently excluded from this colouration group.

The colour of C. brooksi is distinctly different from the above, with four dark bands extending from the anterior margin across about 2/3 of the wing width to about Cu2 or 1A. These are separated by light bands that connect with a light region that extends the length of the posterior portion of the wing. The apical region is preserved as generally light, and may have had complex light colouration in life.

The wing of the Danish C. bittaciformis has a complex series of light and dark bands and spots ( Willmann 1977: Figs. 1–2 ); the undescribed German species figured by Ansorge (2003: Fig 4 G) has a dark wing densely covered with small light spots.

Figures

FIGURE 1. Cimbrophlebia flabelliformis, holotype wing UCCIPR L- 18 F- 763. A, photograph (part); B, drawing from part and counterpart. A, B to scale = 1 cm.

FIGURE 2. Cimbrophlebia leahyi, holotype. A, photograph of the counterpart TRUIPR L- 018 F- 1161; B, photograph of the part TRUIPR L- 018 F- 1160; C, drawing from both the part and counterpart. A – C to scale = 1 cm.

FIGURE 6. Cimbrophlebia westae, holotype wing SRUI 0 99600. A, photograph; B, drawing; C, colouration (simplified to two shades) of C. westae wing, note basal portion obscured by staining, rendered blank. A, B to scale = 1 cm; C scale = 1 cm.

FIGURE 4. A, B, Cimbrophlebia brooksi, holotype wing SR 062005: A, photograph (part); B, drawing from part and counterpart. C, D, C. brooksi, paratype wing SR 990405: C, photograph (part); D, drawing from part and counterpart. A – D to scale = 1 cm.