Aporia crataegi

Jong, Rienk De, 2017, Fossil butterflies, calibration points and the molecular clock (Lepidoptera: Papilionoidea), Zootaxa 4270 (1), pp. 1-63 : 25

crataegi . Aporia crataegi fossilis Kernbach, 1967

Pieridae .

Germany, Hesse, Brandenburg, Willershausen; Plazencian, late Pliocene.

Depository: GPUG (one specimen, 596-12[13589]).

Published figures: Branscheid (1968: Figs 1 , 2 ); Branscheid (1969: Figs 2–5 ); Kernbach (1967: Fig. 12 ). Numerous figures of the extant species in identification guides for European butterflies.

Kernbach (1967) recorded one forewing and two hindwings from the clay of Willershausen as belonging to this extant Palaearctic species. The fossils are not described apart from the observation that the dark stripe between veins 1A+2A and CuA 2 in the hindwing is visible, and that the specimens were apparently larger in the Pliocene. In the accompanying photo of the hindwing the venation is rather similar to that of A. crataegi (Linnaeus) , except for Sc+R1 being much less strongly curved and the cell being distinctly shorter than in the recent species. Actually it is not clear what is typical about the Aporia hindwing venation, a similar venation also being found in the widespread recent genus Pieris and some other pierid genera. Also the stripe mentioned, which actually indicates the lost CuP, is not restricted to Aporia . Kernbach described the fossil as Aporia crataegi fossilis , rather prematurely since it is not even certain that the fossil is conspecific with the extant species.

Apparently, the forewing, mentioned but not described by Kernbach (1967) was reported by Branscheid (1968). It shows the pierid apomorphy of M1 branching off the common stem of R4 and R5 (R3 is considered being lost by various authors). Sc is reconstructed as ending on the costa just beyond the end of the cell, but this may be a misinterpretation, even in fresh Aporia specimens it may be difficult to see where exactly Sc ends on the costa, this vein at its distal end running close to R1. Since the wing is incomplete, the general shape cannot be made out and its identification as belonging to Aporia is not without doubt.

Further wings from the same locality were described by Branscheid (1969) as most probably belonging to Aporia , although he was not sure about the (number of) species, since he found marked differences in size. For calibration purposes these fossils are hardly of interest. Not only are they rather young, but since they cannot reliably be identified even to the subfamily level, we could only use them as calibration point at the root of the Pieridae . (For a recent study of the phylogeny, see Wahlberg et al. 2014, in which the late Pliocene appears far too recent for a divergence time.)

In view of the extreme scarcity of butterfly fossils it is remarkable that so many specimens of a single genus or maybe even species have been found in the same locality. A possible explanation could be gregarious behavior on wet spots involving so called mud puddling that can be observed in many butterflies, including Aporia crataegi and many other Pieridae .

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 11 – 13. Ƒanessa pluto Heer, 1849. Figures copied from (1875), Plate II, figures 1, 17 and 7, respectively. (A), copied by Scudder from original description by Heer; (B) and (C), figures sent to Scudder by Mr. Brunner de Wattenwyl, made after the same object. Note differences in wing shape and other details. Figs 14 – 16. Thaites ruminiana Scudder, 1875. Figures copied from Scudder (1875), Plate III, figures 9, 1 and 3, respectively. (A), underside of fossil; (B), reconstruction of venation; (C), reconstruction of markings. In (A) two separate subcostal veins have been drawn in the forewing, an impossible configuration in Lepidoptera, and apparently a mistake, corrected in (B) and (C). Fig. 17. Cyllo sepulta Boisduval, 1841, wing venation after Scudder (1875). Fig. 18. Butterfly fossil recorded by Wangrin (1939), but shown to be a fraud by Ansorge (2015). Photo kindly provided by J. Ansorge, Horst, Germany (see text for explanation).