The oldest Diptera (Insecta) from the Upper Buntsandstein (early Middle Triassic of Europe
Author
Lukashevich, Elena D.
text
Zootaxa
2021
2021-11-09
5067
1
135
143
journal article
3655
10.11646/zootaxa.5067.1.10
6a67bcc8-1bb3-41b2-8419-641126a9e64e
1175-5326
5656369
27C8082E-56C5-4556-A47B-D6C866F3B41D
Bashkonia
gen. nov.
(
Figure 1
)
Type
species
Bashkonia franconica
sp. nov.
Etymology.
The generic epithet refers to Alexey Bashkuev, a recognized collector and expert on Triassic insects. The name is feminine.
Diagnosis.
Wings elongate, pterostigma large. Crossvein
sc-r
far from Rs origin. R kink long and shallow, opposed to long M+CuA fusion; arculus inclined; R
2+3
fork short and wide; Rs relatively long, more than 2/3 wing length; R
4+5
fork long, 10 times longer than R
4+5
stem; R
5
convexity continued along Rs up to MA, forming false vein
fv
between R and M sectors;
r-m
jointing R
5
base and basal 1/3 of M
1+2
stem. M forking before Rs bifurcation, near wing midlength; M
1+2
and M
3+4
forks rather long and subequal;
im
connecting M
1+2
stem and M
3
; M
1+2
forking far beyond
im;
M
3+4
forking clearly distal to R
4+5
furcation; d cell subequal to M
3+4
fork;
m-cu
in distal wing half, near midlength of d cell, ending on straight M
3+4
. CuA bent at
m-cu
; CuA apex closer to R
1
apex than to Sc apex; CuP entering margin near wing midlength, strongly diverging from CuA in its distal 1/4, CuP being weak after its divergence with cubital fold
icu
. Two cubital folds well developed: curved one behind entire length of CuA and straight one
icu
before CuP to CuA apex. A
1
distal to
cu-a
long.
Species included.
Monobasic.
Comparison.
The new genus differs from both other genera of
Nadipteridae
,
Nadiptera
Lukashevich, 1995
and
Tanus
Krzemiński & Krzemińska,
2003
in
sc-r
position (closer to Rs origin than to Sc apex in
Nadiptera
and
Tanus
), shorter Rs and in CuA, which is longer (instead of apex, closer to level of Sc apex than to R
1
apex) and bent at
mcu
. The new genus shares with
Nadiptera
false vein
fv
between R and M sectors and CuP strongly diverging from CuA (
Fig. 2A
), whereas it shares with
Tanus
M furcation and CuP apex in midlength of the wing and
r-m
proximal to
m-cu
(
Fig. 3
).
Remarks.
Characters typical of the family are observed in the wing venation of the new genus: Sc apex beyond wing midlength, distal to Rs bifurcation, the crossvein
sc-r
not terminal; R distinctly kinked in horizontal plane, Rs forking symmetrically before Sc apex, free R
2
reaching wing margin, R
4+5
fork several times longer than short R
4+5
stem; long convex M base aligned with CuA, M stem forking symmetrically, d cell narrow and long with
m-cu
ending on straight М
3+4
; A
1
not reaching margin, A
2
forming anal loop, anal lobe somewhat produced.
The cubital fold
icu
reaching CuA apex, found in the new genus, is also present in other Triassic
Diptera
, the tipulomorph
Vladiptera
Shcherbakov, 1995
(
Vladipteridae
;
Fig. 2B
) and the psychodomorph
Tillyardiptera
Lukashevich & Shcherbakov, 1999
(Tillyardipteridae)
, but they were missed in the original descriptions (
Shcherbakov
et al
. 1995
: fig. 24;
Lukashevich & Shcherbakov 1999
: fig.1). Such cubital fold is not a common character of
Diptera
but it is well known in extant and extinct
Ptychopteridae
as well as false vein
fv
between R and M sectors and A
1
retaining distal to
cu-
a as a rather long spur (e.g.
Lukashevich 2012
).