Gedanohelea liaoningensis, Steber, Szadziewski & Wang, 2016

Stebner, Frauke, Szadziewski, Ryszard & Wang, Bo, 2016, Biting midges (Diptera: Ceratopogonidae) in Fushun amber reveal further biotic links between Asia and Europe during the Eocene, Palaeontologia Electronica 31 (9), pp. 1-9 : 4-7

Gedanohelea liaoningensis n. sp.

Figures 3.1, 3.3 , 5.1-6

zoobank/ F996CF73-439C-4A48-8C69-5C451B709E68

1. Fore femur slightly swollen ( Figure 2.5 ). Apex of fore tibia without prolongation M. sinica n. sp

-. Fore femur greatly swollen. Apex of fore tibia with distinct prolongation 2

2. Palpal segment 4 slightly shorter than palpal segment 3 M. laca ( Meunier, 1904)

-. Palpal segment 4 almost 2 times shorter than palpal segment 3 M. gedanica Szadziewski, 1988

Material. Holotype female NIGP156998 . Deposited at the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences.

Etymology. The specific epithet refers to the province of Liaoning, from where the amber is collected.

Diagnosis. The species can be distinguished by having wing veins M 1 and M 2 slightly divergent, vein M 1 reaching wing margin at acute angle, and palpal segments 3–4 cylindrical. Males unknown.

Description. Female. Dark brown to black in colour, both antennae broken. Total body length (including head) 0.91 mm.

Head. Flagellum length 0.39 mm, AR 0.92. Antenna with 13 cylindrical flagellomeres, both antennae broken beyond flagellomere 8 but distal 5 flagellomeres of left antenna preserved and dis-

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tinctly elongate, last flagellomere longest ( Figure 5.1 ). Palpus ( Figure 5.3 ) short, most probably with five segments but only terminal three segments clearly visible and about 0.054 mm in length, palpal segment three cylindrical, apparently not distinctly broader than following segments.

Thorax. Hind basitarsus with row of palisade setae. Tarsomeres 2–4 short, tarsomere 4 cordiform, tarsomere 5 longer than preceding one but shorter than combined length of tarsomeres 2–4. Tibial comb composed of at least six spines. Claws single on all legs; claw of foreleg ( Figure 5.4 ) as long as tarsomere 5, claw of mid- and hind legs shorter ( Figure 5.5-6 ). TR(I) 2.67, TR(II)?, TR(III) 3.57. Wing length 0.65 mm, CR 0.51. Ratio of divergence between M 1 and M 2: 0.25. Veins M 1 and M 2 slightly divergent, M 1 reaching wing margin at acute angle ( Figure 5.2 ).

Remarks. Gedanohelea liaoningensis n. sp. and Gedanohelea fushunensis n. sp. closely resemble each other. The only character that separates both species is the shape of the M veins, which are less divergent in G. liaoningensis . In G. fushunensis M 1 meets the wing margin at right angle, while M 1 reaches the wing margin at acute angle in G. liaoningensis .

Having tarsomere 5 of foreleg distinctly shorter than combined length of tarsomeres 2–4, and the claw of foreleg almost as long as tarsomere 5 Gedanohelea liaoningensis and G. fushunensis resemble the Baltic amber species G. loewi . The species differ from each other in the shape of palpal segment 3, which is almost spherical and bearing a small round sensory pit in Gedanohelea loewi but cylindrical in the two Fushun amber species and with a broad oval sensory pit in G. fushunensis . Furthermore, in G. fushunensis vein M 1 meets the wing margin exactly at 90 o instead of an acute angle as in G. loewi .

G. fushunensis can be separated from Gedanohelea wirthi by the length of the claws, which are short on all legs in G. wirthi whereas the claw of the foreleg is long in G. fushunensis , and by the lower ratio of divergence of wing veins M 1 and M 2, which is 0.29 in G. fushunensis and 0.34 in G. wirthi ( Table 2).

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Figures

FIGURE 2. Mantohelea sinica n. sp., Holotype female NIGP156996. 1. Antenna. 2. Wing. 3. Palpus. 4. Fore tibia. 5. Fore femur. 6. Tarsus of foreleg. 7. Tarsus of mid leg. 8. Tarsus of hind leg.

FIGURE 3. Photograph of Gedanohelea fushunensis n. sp. and Gedanohelea liaoningensis n. sp. from lower Eocene Fushun amber 1. Gedanohelea liaoningensis n. sp., Holotype female NIGP156998. 2. Gedanohelea fushunensis n. sp., Holotype female NIGP156997. 3. Detail of wing of Gedanohelea liaoningensis n. sp. with tips of veins M1 and M2 marked. 4. Detail of wing of Gedanohelea fushunensis n. sp. with tips of veins M1 and M2 marked.

FIGURE 5. Gedanohelea liaoningensis n. sp., Holotype female NIGP156998. 1. Flagellum. 2. Wing. 3. Palpal segments 3-5. 4. Tarsus of foreleg. 5. Tarsus of mid leg. 6. Tarsus of hind leg.

FIGURE 6. Palaeogeographic locations of early Eocene insect faunas in (approximately 50 Ma) Baltic amber (B) from Europe and Fushun amber (F) from China (modified after Blakey, 2015).