Revision of fossil Bibionidae (Insecta: Diptera) from French Oligocene deposits
Author
Skartveit, John
Author
Nel, André
text
Zootaxa
2017
4225
1
1
83
journal article
37263
10.5281/zenodo.259087
05be601b-f9f1-4952-ac09-7012ef31aab0
1175-5326
259087
4676EE59-569B-4197-B108-9B32FD88E68E
Penthetria gigantea
(
Théobald, 1937
)
comb.n.
(Figs. 6
–
9, 78
–
80)
Plecia gigantea
Théobald, 1937
: 226
–
227.
Plecia crassiventris
Théobald, 1937
: 227
. Syn.n.
Plecia miegi
Théobald, 1937
: 232
–
233. Syn.n.
Plecia luteipennis
Théobald, 1937
: 233
. Syn.n.
Material examined.
Holotype (female) of
Plecia gigantea
NMB F1380, (fig. 6). Paratypes (females) of
Plecia gigantea
NMB F460, F1388. Holotype (female) of
Plecia crassiventris
NMB F1381, (fig. 7). Paratypes (females) of
Plecia crassiventris
NMB F1389/1, F1389/2. Holotype (male) of
Plecia miegi
NMB F1399 (fig. 8), part + counterpart. Paratypes (males) of
Plecia miegi
NMB F1400, F1401. Holotype (male) of
Plecia luteipennis
NMB F1402/F2420 (fig. 9) (part and counterpart of same specimen). Paratype (male) of
Plecia luteipennis
NMB F1413.
Localities.
Kleinkembs.
Diagnosis.
A large (
8–13.5 mm
) and slender
Penthetria
with relatively long and slender legs. Antennal flagellum probably 8-segmented. Male epandrium subtriangular, gonostylus conical, apically slender. Wing yellowish fumose in male, brownish in female. Vein R2+3 nearly straight with a small bend in middle.
Redescription.
Male: Total length 8.0
–
13.5 mm
(N=4). Entirely black.
Head: Length
1.1
–
1.5 mm
(N=4), width
1.1 mm
(N=2). Antennal flagellum cylindrical, approximately 8- segmented.
Thorax: Length 2.1
–
3.0 mm (N=4), width
1.7
–
2.4 mm
(N=2). Haltere dark brown.
Wing (fig. 78): Length
9.1
–
11.6 mm
(N=3), width
3.2
–
3.4 mm
(N=2), length/width = 3.02
–
3.40 (N=3). Light brown fumose with brown R-veins, posterior veins colourless.
Costa
extends some distance beyond apex of R4+5. Humeral vein present, Subcosta long and horizontal. R2+3 rather straight, oblique. Pterostigma inconspicuous. Basal part of Rs subparallel to M. Fork of M relatively long. Wing vein measurements in
Table 1
.
Legs: relatively long and slender, dark brown. Femorae slightly clavate. Femur 1 length
3.2
–
3.6 mm
(N=2), tibia1 length
3.3
–
3.6 mm
(N=2), femur 3 length
3.4
–
4.5 mm
(N=3), tibia 3 length
3.8
–
4.3 mm
(N=2).
Abdomen: Length
4.6
–
9.6 mm
(N=5), width 1.0
–
1.4 mm
(N=2). Brown, slender, cylindrical. Abdominal pile rather short.
Terminalia (fig. 80): Epandrium rather small, subtriangular. Gonostylus robust, almost straight, sharply pointed. Hypopygium width
1.3
–
1.5 mm
(N=2), gonostylus length
0.64
–
0.67 mm
(N=2).
Female: Total length
9.2
–
13.5 mm
(N=4). Entirely black.
Head: Length
0.9
–
1.2 mm
(N=3), width 0.7
–
1.0 mm (N=2). Relatively small, oval, longer than broad. Compound eyes do not protrude. Antennal flagellum cylindrical, probably eight-segmented.
Thorax: Length
2.8
–
4.6 mm
(N=6), width
2.3
–
3.2 mm
(N=4). Black. Sulci deep and conspicuous. Pile not conspicuous. Haltere yellowish-brown.
Wing (fig. 79): Length
9.4
–
11.5 mm
(N=6), width 3.0
–
3.8 mm
(N=3), length/width = 2.95
–
3.77 (N=4). Brown fumose. Radial veins light brown, strong, more posterior veins fine and inconspicuous. Pterostigma invisible. Venation as in male. Wing vein measurements in
Table 1
.
Legs: Dark brown. Long and slender, femorae slightly clavate. Tibia 3 length
5.1 mm
(N=1).
Abdomen: Length
5.9
–
8.1 mm
(N=3), width
2.5
–
3.2 mm
(N=4). Dark brown, cylindrical. Pile not conspicuous.
Terminalia: Cercus two-segmented as usual for genus, rather small, pointed.