Lethe montana

Jong, Rienk De, 2017, Fossil butterflies, calibration points and the molecular clock (Lepidoptera: Papilionoidea), Zootaxa 4270 (1), pp. 1-63 : 32

montana . Lethe montana Miller, Miller & Ivie, 2012

Nymphalidae : Satyrinae .

USA, Montana , Canyon Ferry Reservoir; Rupelian, early Oligocene.

Depository: holotype, Museum of Rockies, Montana State University , Bozeman (part and counterpart, MOR No. MV-152).

Published figures: CoBabe et al. (2002, Fig. 4 c), Miller et al. (2012: Figs 1–5 .

The fossil consists of a well preserved part and counterpart of a forewing. In their diagnosis the authors state that “… the unbranched forewing radial veins … indicate thet this fossil is … not a member of the Hesperioidea.” Rather, this should read “the branched forewing radial veins”, but the conclusion is correct. Moreover, the absence from the cubital spur and vein 3A eliminates Papilionidae from consideration. The authors also eliminate Pieridae , since M1 branches off the cell, although branching of M1 off R3 is widespread in Pieridae but not universal. The remark that Riodinidae or Lycaenidae can be eliminated because the “… veins are not simple in that they do not arise from the base or from the radius or cubitus proper …”, is not clear to me. The authors arrive at the conclusion that the fossil belongs to the Nymphalidae , and since the forewing cell is closed, the subcostal vein is thickened at its base and there is a prominent ocellus in M1-M2, assignment to the Satyrinae seems obvious. The only problem is, that the basal part of the wing with the swelling of the subcostal vein, as represented in their reconstruction in Fig. 5 , is absent from the fossil ( Fig. 1 ) and from the interpretation of the fossil in Fig. 2 .

See also the discussion under Lethe (?) corbieri on the absence of a basal swelling in Lethe . There is no convincing evidence for treating Lethe montana differently than Lethe (?) corbieri as far as its use as calibration point concerns. They are approximately the same age.

See also under Biogeographic considerations.

Figures

FIGURE 1. Localities of fossil butterflies plotted ion a modern map. See Table 1 for further, complementary information.

FIGURE 2. Apomorphies, their placement on a tree, and the assignment of calibration points. See text for explanation.

FIGURES 3 – 4. Wing venation of (A) Pareronia Bingham, 1907 (Pieridae), and (B) Hasora Moore, 1881 (Hesperiidae). See text for explanation.

FIGURE 5. Ƒanessa amerindica Miller & Brown, 1989, holotype, collections of Invertebrate Paleontology, University of Florida. Photo by Roger Portell. Fig. 6. Pseudoneorina coulleti Nel & Descimon, 1984. France, Dép. Alpes-de-Haute- Provence, Dauphin, specimen in coll. M. Henrotay; photo by courtesy of M. Henrotay. Fig. 7. Archaeolycorea ferreirai Martins-Neto, 1989. Fig. 4 A of original description. Fig. 8. Oligodonta florissantensis Brown, 1976, holotype, collections of Invertebrate Paleontology, University of Florida. Photo by courtesy of Akito Kawahara. Fig. 9. Neorinella garciae Martins- Neto, Kucera-Santos, de Moraes Vieira & de Campos Fragoso, 1993. Fig. 3 A of original description. Fig. 10. Protocoeliades kristenseni de Jong, 2016, holotype, Zoologisk Museum, Copenhagen, Denmark. Photo by Department of Paleobiology, National Museum of Natural History, Washington DC, USA.