New chironomid flies in Early Cretaceous Lebanese amber (Diptera: Chironomidae)
Author
Veltz, Isabelle
Author
Azar, Dany
Author
Nel, André
text
African Invertebrates
2007
2007-04-30
48
1
169
191
journal article
10.5281/zenodo.7667523
2305-2562
7667523
Wadelius libanicus
sp. n.
Figs 7, 8
Etymology: After
Lebanon
.
Description: Head
0.25 mm
long, 0.52 high. Ocelli absent. Antenna
0.8 mm
long, more than 3 times longer than head, distinctly hairy, with 14 flagellomeres, flagellomeres 1–13 covered with long setae (shortest
0.05 mm
long, longest
0.4 mm
long), scape broad and short, rounded, pedicel very short, flagellomere 13 long (
0.3 mm
), flagellomere 14 evenly tapering from base to apical nipple,
0.09 mm
long. Eye bare, with apically expanded dorso-medial extension. Clypeus
0.13 mm
long, with few dorsal setae. Mouthparts lacking functional mandible; all palpomeres with numerous setae; labium
0.23 mm
. Uniserial postocular setae; numerous long frontal setae visible; inner vertical and outer vertical setae not visible.
Thorax
0.93 mm
long,
0.92 mm
high; antepronotum bare; postnotum bearing long setae and with longitudinal groove; scutal tubercle present; scutellum with broken setae; numerous acrostichals, supraalar and prealar setae; postanepisternal setae present.
Wing macropterous,
1.6 mm
long,
0.42 mm
wide, hyaline, covered with macrotrichia.
Costa
ending just beyond insertion of last branch of radius, produced by
0.06 mm
, shorter than cross-vein RM. Radius with only 3 branches R 1, R 2+3, and R 4+5; R 2+3 well separated from R 1 and R 4+5, R 2+3 clearly visible at base and apex but evanescent in its main part; R 2
0.02 mm
long, ending in R 1, R 3
0.15 mm
long, ending in costa. Only M 1+2 and M 3+4 present; cross-vein MCu present. Cubital fork
0.05 mm
proximal to crossvein MCu; cross-vein RM
0.02 mm
distal of MCu. Anal vein An 2 absent. Halter
0.2 mm
long.
Fore femur length
0.7 mm
, tibia
0.82 mm
, tarsus
1.08 mm
; mid femur
0.7 mm
, tibia
0.84 mm
, tarsus
0.96 mm
; hind femur
0.6 mm
, tibia
0.86 mm
, tarsus
1.22 mm
. Tibial spur formula 1–2–2, with no lateral teeth; two robust and curved claw-like spines on tibial end,
0.04 mm
long; hind tibial comb disposed in one row. Fourth tarsomeres of all legs cylindrical, not cordiform; claw simple, not pectinate.
Abdomen
1.4 mm
long,
0.4 mm
wide. Gonostylus
0.15 mm
long; gonocoxite
0.22 mm
long,
0.15 mm
wide at base, with numerous long setae. Anal point very smooth and broad, though small;
0.04 mm
wide at base,
0.05 mm
high.
Holotype
: Specimen 748A, male.
LEBANON
:
Mont Lebanon district
[
Mouhafazit Jabal Loubnan
]: Hammana / Mdeyrij, Caza Baabda; Early Cretaceous (
D. Azar
coll.).
Paratype
: Specimen 259 (male), same data as holotype.
Discussion: This peculiar tanypodine may deserve a separate tribe. However, one of the most distinct and unique synapomorphies within the
Tanypodinae
is the comb-like formation of the tibial spurs. The only recent tanypodine without such tibial spurs belongs to the tribe
Anatopyniini
with the single included genus
Anatopynia
Johannsen, 1905
. Similarities between
Wadelius
and this tribe also are found in the extensive thoracic chaetotaxy and in the probable absence of an inferior volsella. The wing venation is also similar although the costa is more produced and the cubital fork is more proximal to cross-vein MCu in
Anatopynia
. In addition, unlike
Anatopynia
,
Wadelius
has a scutal tubercle.
Figs 7, 8.
Wadelius libanicus
gen. et sp. n.
: (7) wing, holotype 748A, scale bar = 0.5 mm; (8) male genitalia, paratype 259, scale bar = 0.1 mm.
The two genera
Tanypus
Meigen, 1803
and
Nilotanypus
Kieffer, 1923
have very rudimentary comb-like structures, which are very difficult to see.
Wadelius
has similar tibial spurs, but it differs from the former genus in the MCu and cubital fork position, and from the latter in the presence of a divided R
2+3
. We tentatively attribute
Wadelius
to the
Anatopyniini
.