Fossil butterflies, calibration points and the molecular clock (Lepidoptera: Papilionoidea)
Author
Jong, Rienk De
text
Zootaxa
2017
4270
1
1
63
journal article
32975
10.5281/zenodo.583183
6c479acc-8b18-4f0b-a6e5-85bcd6d7b6b7
1175-5326
583183
2D00AFF5-4FE2-4EC1-A328-C8670CFB8D6D
leuce
.
Apanthesis leuce
Scudder, 1889
Incertae sedis.
USA
,
Colorado
,
Teller County
, Florissant; late Priabonian, late Eocene.
Depository: MCZH (holotype, 16354).
Published figures:
Emmel
et al
. (1992
:
Fig. 1
/10);
Scudder (1889: Pl. LII
Figs. 12, 13
)
.
One forewing only, with venation and design well preserved. Radial formula 1, 2, 3+(4+5), udc absent, M1, R3+(4+5) and mdc almost originating from the same point; ldc weak. According to Scudder, the radial branching is typical for the “tribe Vanessidi” (
Nymphalidae
), but I do not know what is so typical about it, except for the weak ldc.
Comstock (1961: 181)
observed a closer similarity to
Limenitis
, with which also the markings correspond with a uniformously brown hue with a submarginal band parallel to termen and consisting of light-coloured, slightly kidney-shaped spots, and vague spots between the band and termen in intervenal areas). Because
Limenitis
and
Anaea
share characters in the male genitalia,
Comstock (1961)
considered the discovery of
Apanthesis leuce
an indication of a northern origin of
Anaea
. This is, however, an unwarranted speculation. The venational arrangement could as well be plesiomorphic and is, for instance, also similar to the arrangement in the pierid genus
Eronia
.
Euronia
was considered a primitive member of the pierid tribe
Pierini
by
Klots (1931)
based on morphological grounds.
Braby
et al
. (2006)
concluded from a molecular analysis of the
Pieridae
, that
Euronia
was grouped in the
Colotis
group of genera, the first offshoot of the
Pierinae
. The weakness of ldc may be an argument in favor of
Nymphalidae
, but it remains to be seen whether in a fossil of some 35 Ma of age the weak ldc in, e.g.,
Limenitis
, can be distinguished from the rather weak ldc in
Eronia
. The only reason for considering the fossil a member of the
Nymphalidae
is, therefore, the similarity in wing markings to some recent species, a rather weak argument.
Emmel
et al
. (1992)
followed Scudder's decision; they did not mention Comstock’s remarks. I think it is wise to consider the fossil as without clear affinities, as long as elements of the wing design remain unstudied in a phylogenetic context.