Spatalistiforma submerga Skalski, 1992

Heikkilä, Maria, Brown, John W., Baixeras, Joaquin, Mey, Wolfram & Kozlov, Mikhail V., 2018, Re-examining the rare and the lost: a review of fossil Tortricidae (Lepidoptera), Zootaxa 4394 (1), pp. 41-60 : 52

Spatalistiforma submerga Skalski, 1992

Figs 4 a–b.

Excavation locality and depository: ZMCD Copenhagen (Holotype: 12-4/1957=LEP.SUCC.88 UZMC/AWS) / Baltic Region (Baltic Amber, Prussian Fm.)/ Lutetian, Middle Eocene. The specimen was borrowed and examined at the USNM by JWB, MH and Richard L. Brown .

Published illustrations: Skalski 1992: 142, fig. 6 (photographs and drawings).

Condition: The moth is in a 7 × 9 × 4 mm piece of Baltic amber. The head, abdomen and legs are missing; only the thorax and the wings have been preserved. Forewing length is 3 mm. The presence of a single acanthus in the frenulum suggests the moth is a male and belongs to Heteroneura.

Comments: The first mention of Spatalistiforma submerga by Skalski (1976) must be considered a nomen nudum since it lacks a description. However, Skalski (1992) subsequently validated the name by providing a description. Skalski (1992) tentatively placed the fossil moth in the tribe Tortricini based on purported similarities in the wing venation with the genus Spatalistis Meyrick, 1907 . According to Skalski, among recent Tortricidae , only Spatalistis has M 3 and CuA 1 veins stalked in both the fore and hindwing. However, Skalski acknowledged that the wing shape and at least two venational features of Spatalistiforma are different from those found in Spatalistis and allied genera.

There are no characters that convincingly assign the specimen to Tortricidae , and there are subtle features that suggest it is not a tortricid. The overall shapes of both the forewing and hindwing are not particularly characteristic of Tortricidae . In the forewing the termen is strongly angled inward, giving it an appearance that is more tineoid than tortricoid. In most tortricids, especially Tortricini (and most other Tortricinae ), the termen is oblique or slightly angled inward, giving the forewing a much more triangular appearance. Plus, the forewing pattern (which appears to be somewhat intact) is reminiscent of a tineid and not a tortricid. The unusual, long, slender scales from the costa of the forewing are present in no known tortricids, but we know of no other family with such forewing scales. The hindwing, likewise, has a shape that is more typical of Tineoidea and/or Yponomeutoidea (e.g. Plutellidae , Yponomeutidae ), somewhat broadly lanceolate-rounded. In Fig. 4b the vague presence on the hindwing of a darker patch reminiscent of male secondary scales found in many tortricids is actually a detached leg with a tibial spur. Overall, the specimen bears little resemblance to Spatalistis , which has a strongly oblique forewing termen and raised scales on the forewing.

This fossil was used as a calibration point in the divergence time study by Fagua et al. (2017) to give a minimum age to Tortricinae . Based on the reasons given above, we find the original interpretation of the fossil as a tortricid unwarranted and its use as a calibration point for the purpose intended incorrect.

Figures

FIGURE 4. Spatalistiforma submerga Skalski, 1992. ZMCD (HT: 12-4/1957=LEP.SUCC.88 UZMC/AWS). Baltic amber. a. Dorsal view. Length of forewing 3 mm. b. Ventral view. For details of venation see Skalski (1992). Photos: Maria Heikkilä.