Eotrichocera (Archaeotrichocera) amabilis, Dong, Fei, Shih, Chungkun & Ren, Dong, 2014

Dong, Fei, Shih, Chungkun & Ren, Dong, 2014, Two new species of Trichoceridae from the Middle Jurassic Jiulongshan Formation of Inner Mongolia, China, ZooKeys 411, pp. 145-160 : 150-152

Eotrichocera (Archaeotrichocera) amabilis sp. n.

Etymology.

The specific name of “amabilis” is a Latin word, meaning lovely.

Diagnosis.

Body small and wing short; Sc 0.71 times as long as wing; the d-cell broad (about 1.7 times as long as wide); A2 short and bending sharply toward posterior margin (angle about 128°).

Holotype.

An almost complete female specimen with well-preserved body, wings and head. Specimen number CNU-DIP-NN2013134, Wing length 5.2 mm, width 2.2 mm (Figs 4 A–D, 5A, 6).

Paratype.

A specimen with body and wings with partial venation, specimen number CNU-DIP-NN2013132, (Figs 4E, 5B).

Locality and horizon.

Jiulongshan Formation, Late Middle Jurassic, Daohugou Village, Ningcheng County, Inner Mongolia Autonomous Region, China.

Description.

Based on Holotype, different characters of the paratype CNU-DIP-NN2013132 in brackets. Medium-sized winter crane flies, head length 0.47 mm, body length (including head) 5.8 mm with well preserved body and wings. [Paratype with partial body and wings with partial venation].

Head: antenna very long, about 5.7 times as long as the head length, palpi about two times as long as the head length, compound eyes preserved (Figs 4C, 6).

Thorax: Much higher, in lateral view, than that of the abdomen, subcircular in shape, with robust and well-developed mesonotum.

Wings: Wing is shorter than abdomen, not covering the end of the abdomen. Wing length of 5.2 mm [Paratype with wing length 5.0 mm], narrow and long (L/W=2.2); venation clear, Sc rather short about 0.71 times as long as the wing and terminating clearly proximad of R2; crossvein sc-r locating at 1/3 [Paratype 1/2] of Rs, and distad to the Sc ending; [Paratype Rs arising about one-fourth from the base of the wing]; Rs forking at 0.55 [Paratype 0.64] times of wing length; R2+3 about 1.9 times as long as R2+3+4; R2 about 0.18 of length of R3; R3 almost 3.7 times as long as the R2+3; R5 9.0 times as long as R2+3+4; M1 1.6 times of the dM1+2; crossvein m-m well developed about 0.73 times as long as bM3, closing the d-cell and nearly 0.17 [Paratype 0.21] times as long as wing; bM1+2 nearly 2.1 times as long as the length of the r-m and the latter at one-fourth of the d-cell; d-cell broad (W/L=0.58 [Paratype 0.56]) and almost 0.17 times of length of wing; Cu long, curved (angle about 121°) and reaching the wing posterior margin at 0.67 from the base of the wing; the stem of A divided into A1 and A2; A1 long, slightly curving and reaching the wing posterior margin; A2 short, 0.13 times as long as wing and almost 0.25 times as long as length of A1, bending sharply and reaching the wing posterior margin.

Abdomen: Abdomen relatively long and thin, with ten segments. Female genitalia discernible (Figs 4 A–C) [Paratype genitalia indiscernible].

Legs: Legs slender and long; the hind leg nearly 1.5 times as long as the abdomen and 1.4 times as long as the wing. Tarsus with five segments; the first segment of tarsus (t1) is 1.2 times as long as t2 in mid leg.

Remarks.

The new species is compared and differentiated from all other species in Eotrichocera (Archaeotrichocera) in Table 2.

Due to limitation of fossil preservation, some of the morphological characters of previously described fossil are not objective or clear. We set up an aforementioned key based on the Sc length and ending location at anterior margin, wing length, crossvein sc-r position, Rs forking location and A2 length, to differentiate the species of subgenus Archaeotrichocera . These characters may help future morphological and taxonomic studies in differentiating fossil species of Trichoceridae .