ZooKeys 411: 145–160, doi: 10.3897/zookeys.411.6858
Two new species of Trichoceridae from the Middle Jurassic Jiulongshan Formation of Inner Mongolia, China
Fei Dong 1,†, Chungkun Shih 2,‡, Dong Ren 1,§
1 College of Life Sciences,
2 Capital Normal University, 105 Xisanhuanbeilu, Haidian District, Beijing 100048, China

Corresponding author: Dong Ren (rendong@mail.cnu.edu.cn)

Academic editor: Jes Rust

received 19 December 2013 | accepted 7 May 2014 | Published 28 May 2014
(C) 2014 Fei Dong. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
For reference, use of the paginated PDF or printed version of this article is recommended.

Citation: Dong F, Shih C-K, Ren D (2014) Two new species of Trichoceridae from the Middle Jurassic Jiulongshan Formation of Inner Mongolia, China. ZooKeys 411: 145–160. doi: 10.3897/zookeys.411.6858

Abstract

Two new species, Eotrichocera (Archaeotrichocera) longensis sp. n. and Eotrichocera (Archaeotrichocera) amabilis sp. n. of Trichoceridae are described based on a combination of the following characters: Sc ending proximad of the forking of R2, shape of d cell and A2 rather short and bending sharply toward posterior margin. These fossil specimens were collected from the Middle Jurassic Jiulongshan Formation of Daohugou in Inner Mongolia, China.

Keywords

Diptera, Eotrichocera, Archaeotrichocera, Fossil, Daohugou

Introduction

Trichoceridae is a family of medium-sized dipterans, commonly called winter crane flies, Yang and Yang (1995) found that just a few adults can live in cold environment, even in winter, and indicated that the name of winter crane flies might not be proper. However, the adults (include the largest species of Trichocera) not only live in cold environment, but also mate and lay eggs under the snow cover in winter (Hågvar and Krzemińska 2007). Hence, the common name of winter crane flies is proper. The adults live in damp places close to lakes, rivers, or streams and most of them feed on plant fluids (Yang 2009); while the larvae live in moist or wet or terrestrial biotopes and feed on plant debris, decaying leaves in forests, mushrooms and animal droppings (Dahl and Alexander 1976) or take cankered plants or animal bodies as food (Yang 2009).

There are 77 species of fossil and amber trichocerids, which have been assigned into three subfamilies: Trichocerinae, Paracladurinae and Kovalevinae; and twelve genera: Cladoneura Scudder, 1894; Eotrichocera Kalugina, 1985; Rasnitsynina Krzemińska, Krzemiński & Dahl, 2009; Mailotrichocera Kalugina, 1985; Paleotrichocera Kalugina, 1986; Karatina Krzemińska, Krzemiński, Dahl & Lukashevich, 2009; Trichocera Meigen, 1803; Tanyochoreta Zhang, 2006; Zherikhinina Krzemińska, Krzemiński & Dahl, 2009; Undaya Krzemińska, Krzemiński & Dahl, 2009; Kovaleva Krzemińska, Krzemiński & Dahl, 2009; Paracladura Brunetti, 1911 (Krzemińska et al. 2009a). The oldest species of trichocerids, Mailotrichocera variabilis, Mailotrichocera mikereichi and Mailotrichocera zessini have been described from Lower Jurassic of Germany (Krzemińska et al. 2009a).

Among them, there are eight species in three genera described from the Daohugou locality of China: Eotrichocera (Archaeotrichocera) ephemera Zhang, 2006; Tanyochoreta integera Zhang, 2006; Tanyochoreta chifengica Zhang, 2006; Tanyochoreta (Sinotrichocera) parva Zhang, 2006; Eotrichocera (Archaeotrichocera) conica Krzemińska, Krzemiński & Ren, 2009; Eotrichocera (Archaeotrichocera) rara Krzemińska, Krzemiński & Ren, 2009; Eotrichocera (Archaeotrichocera) spatiosa Liu, Shih & Ren, 2012 and Zherikhinina reni Krzemińska, Krzemiński & Dahl, 2009.

Furthermore, Sinotrichocera Zhang, 2006 has been changed as a subgenus belonging to Tanyochoreta; Oligotrichocera Dahl, 1971 as a subgenus belonging to Trichocera Podenas, 2001; Trichonomites Kalugina, 1986 and Paleotrichocera Kalugina, 1986 are synonymized (Krzemińska et al. 2009a). All genera and species of Trichoceridae Kertész, 1902, after revisions and transfers, are summarized in Table 1, which is updated and expanded from the Tables 1 and 4 in Krzemińska et al. 2009a.

Table 1.

Fossil species of Trichoceridae Kertész, 1902.

Genus Species Author(s) Date Age Locality
Cladoneura Cladoneura willistoni Scudder 1894 Lower Oligocene Florissant, USA
Eotrichocera (Archaeotrichocera) Eotrichocera (Archaeotrichocera) ephemera Zhang 2006 Middle Jurassic Daohugou, China
Eotrichocera (Archaeotrichocera) conica Krzemińska, Krzemiński & Ren 2009a Middle Jurassic Daohugou, China
Eotrichocera (Archaeotrichocera) rara Krzemińska, Krzemiński & Ren 2009a Lower Cretaceous Kempendyay, Russia
Eotrichocera (Archaeotrichocera) spatiosa Liu, Shih & Ren 2012a Middle Jurassic Daohugou, China
Eotrichocera (Eotrichocera) Eotrichocera (Eotrichocera) christinae Kalugina 1985 Lower Jurassic or earlier Middle Jurassic Novospasskoe, Russia
Karatina Karatina longipes Rohdendorf 1964 Upper Jurassic Karatau, Kazakhstan
Karatina explorans Krzemińska, Krzemiński, Dahl & Lukashevich 2009a Lower Cretaceous Baissa, Russia
Karatina pellita Krzemińska, Krzemiński, Dahl & Lukashevich 2009a Upper Jurassic Karatau, Kazakhstan
Kovaleva (Kovaleva) Kovaleva (Kovaleva) fragmentosa Krzemińska, Krzemiński & Dahl 2009a Jurassic/Cretaceous boundary Unda and Daya, E. Transbaikalia
Kovaleva (Kovaleva) hirsuta Krzemińska, Krzemiński & Dahl 2009a Jurassic/Cretaceous boundary Daya, E. Transbaikalia
Kovaleva (Kovaleva) obscura Krzemińska, Krzemiński & Dahl 2009a Jurassic/Cretaceous boundary Daya, Unda and Shevia, E. Transbaikalia
Kovaleva (Kovaleva) sheviae Krzemińska, Krzemiński & Dahl 2009a Jurassic/Cretaceous boundary Shevia, E. Transbaikalia
Kovaleva (Kovaleva) volodii Krzemińska, Krzemiński & Dahl 2009a Jurassic/Cretaceous boundary Daya, E. Transbaikalia
Kovaleva (Vladimirevna) Kovaleva (Vladimirevna) mirabilis Krzemińska, Krzemiński & Dahl 2009a Jurassic/Cretaceous boundary Daya, E. Transbaikalia
Mailotrichocera Mailotrichocera jurassica Kalugina 1985 Uppermost middle or earliest Upper Jurassic Uda, E. Transbaikalia
Mailotrichocera gracilis Krzemińska, Krzemiński & Dahl 2009a Jurassic/Cretaceous boundary Daya, Unda and Shevia, E Transbaikalia
Mailotrichocera mikereichi Krzemińska, Krzemiński & Ansorge 2009a Lower Jurassic Dobbertin, Germany; Grimmen, Germany
Mailotrichocera ovifera Krzemińska, Krzemiński & Dahl 2009a Jurassic/ Cretaceous boundary Unda, E. Transbaikalia
Mailotrichocera prisca Krzemińska, Krzemiński & Dahl 2009a Jurassic/Cretaceous boundary Unda and Shevia, E. Transbaikalia
Mailotrichocera sukachevae Krzemińska, Krzemiński & Dahl 2009a Jurassic/Cretaceous boundary Unda, E Transbaikalia
Mailotrichocera variabilis Krzemińska, Krzemiński & Ansorge 2009a Lower Jurassic Dobbertin, Germany; Grimmen, Germany
Mailotrichocera zessini Krzemińska, Krzemiński & Ansorge 2009a Lower Jurassic Grimmen, Germany
Paleotrichocera Paleotrichocera mongolica Kalugina 1986 Lower Cretaceous Gurvan Erenyi Nuru, Mongolia
Paracladura Paracladura caucasiana Krzemińska, Krzemiński & Dahl 2009a Middle Miocene Stavropol, Caucasus
Rasnitsynina Rasnitsynina collecta Krzemińska, Krzemiński & Dahl 2009a Jurassic/Cretaceous boundary Shevia, E. Transbaikalia
Rasnitsynina minae Krzemińska, Krzemiński & Dahl 2009a Jurassic/Cretaceous boundary Shevia and Daya, E Transbaikalia
Tanyochoreta (Sinotrichocera) Tanyochoreta (Sinotrichocera) parva Zhang 2006 Middle Jurassic Daohugou, China
Tanyochoreta (Tanyochoreta) Tanyochoreta (Tanyochoreta) chifengica Zhang 2006 Middle Jurassic Daohugou, China
Tanyochoreta (Tanyochoreta) integera Zhang 2006 Middle Jurassic Daohugou, China
Tanyochoreta (Trichokara) Tanyochoreta (Trichokara) composita Krzemińska, Krzemiński & Dahl 2009a Upper Jurassic Karatau, Kazakhstan
Tanyochoreta (Trichokara) fracta Krzemińska, Krzemiński & Dahl 2009a Upper Jurassic Karatau, Kazakhstan
Tanyochoreta (Trichokara) minuta Krzemińska, Krzemiński & Dahl 2009a Upper Jurassic Karatau, Kazakhstan
Tanyochoreta (Trichokara) tenuis Krzemińska, Krzemiński & Dahl 2009a Upper Jurassic Karatau, Kazakhstan
Tanyochoreta (Trichokara) zagadka Krzemińska, Krzemiński & Dahl 2009a Jurassic/Cretaceous boundary Unda, E Transbaikalia
Tanyochoreta (Trichokara) zbulwami Krzemińska, Krzemiński & Dahl 2009a Jurassic/Cretaceous boundary Daya and Unda, E Transbaikalia
Trichocera Trichocera scudderi Meunier 1915 Upper Oligocene Rott, Germany
Trichocera miocaenica Statz 1934 Upper Oligocene Rott, Germany
Trichocera antiqua Dahl 1971 Upper Eocene Baltic
Trichocera primaeva Dahl 1971 Upper Eocene Baltic
Trichocera fujiyamai Gentilini 1984 Upper Miocene Monte Castellaro, Italy
Trichocera anbar Podenas 2001 Upper Eocene Baltic
Trichocera bona Podenas 2001 Upper Eocene Baltic
Trichocera cerea Podenas 2001 Upper Eocene Baltic
Trichocera diluta Podenas 2001 Upper Eocene Baltic
Trichocera ebenos Podenas 2001 Upper Eocene Baltic
Trichocera christelae Krzemińska, Krzemiński & Dahl 2009a Upper Eocene Baltic
Trichocera corami Krzemińska, Krzemiński & Dahl 2009a Lower Cretaceous Purbeck, UK
Trichocera cretacea Krzemińska, Krzemiński & Dahl 2009a Lower Cretaceous Baissa, Russia
Trichocera hanswerneri Krzemińska, Krzemiński & Dahl 2009a Upper Eocene Baltic
Trichocera turgana Krzemińska, Krzemiński & Dahl 2009a earlier Lower Cretaceous Turga, E. Transbaikalia
Undaya Undaya alata Krzemińska, Krzemiński & Dahl 2009a Jurassic/Cretaceous boundary Unda and Shevia, E. Transbaikalia
Undaya comis Krzemińska, Krzemiński & Dahl 2009a Jurassic/Cretaceous boundary Unda, E. Transbaikalia
Undaya gargantuina Krzemińska, Krzemiński & Dahl 2009a Jurassic/Cretaceous boundary Daya and Unda, E. Transbaikalia
Undaya hilara Krzemińska, Krzemiński & Dahl 2009a Jurassic/Cretaceous boundary Unda and Shevia, E. Transbaikalia
Undaya kaluginae Krzemińska, Krzemiński & Dahl 2009a Jurassic/Cretaceous boundary Daya, E. Transbaikalia
Undaya lenae Krzemińska, Krzemiński & Dahl 2009a Upper Jurassic Shar-Teg, Mongolia
Undaya lukashevichae Krzemińska, Krzemiński & Dahl 2009a Upper Jurassic Shar-Teg, Mongolia
Undaya maxima Krzemińska, Krzemiński & Dahl 2009a Lower Cretaceous Kempendyay, Russia
Undaya mitis Krzemińska, Krzemiński & Dahl 2009a Jurassic/Cretaceous boundary Daya and Unda, E. Transbaikalia
Undaya molesta Krzemińska, Krzemiński & Dahl 2009a Jurassic/Cretaceous boundary Unda and Daya, E. Transbaikalia
Undaya namdyriensis Krzemińska, Krzemiński & Dahl 2009a Lower Cretaceous Kempendyay, Russia
Undaya parvula Krzemińska, Krzemiński & Dahl 2009a Jurassic/Cretaceous boundary Daya and Unda, E. Transbaikalia
Undaya pura Krzemińska, Krzemiński & Dahl 2009a Jurassic/Cretaceous boundary Unda and Daya, E. Transbaikalia
Undaya salsa Krzemińska, Krzemiński & Dahl 2009a Lower Cretaceous Kempendyay, Russia
Undaya savina Krzemińska, Krzemiński & Dahl 2009a Jurassic/Cretaceous boundary Savina, E. Transbaikalia
Undaya saxea Krzemińska, Krzemiński & Dahl 2009a Lower Cretaceous Kempendyay, Russia
Undaya triangula Krzemińska, Krzemiński & Dahl 2009a Lower Cretaceous Kempendyay, Russia
Zherikhinina Zherikhinina itatica Kalugina 1985 Middle Jurassic Kubekovo, Russia
Zherikhinina alastos Krzemińska & Lukashevich 2009b Upper Jurassic Shar Teg, Mongolia
Zherikhinina baissana Krzemińska, Krzemiński & Dahl 2009a Lower Cretaceous Baissa, Russia
Zherikhinina bontsagana Krzemińska, Krzemiński & Dahl 2009a Lower Cretaceous Bon Tsagan, Mongolia
Zherikhinina karatavica Krzemińska, Krzemiński & Dahl 2009a Upper Jurassic Karatau, Kazakhstan
Zherikhinina novospasskaya Krzemińska, Krzemiński & Dahl 2009a later Lower or early Middle Jurassic Novospasskoe, Russia
Zherikhinina reni Krzemińska, Krzemiński & Dahl 2009a Middle Jurassic Daohugou, China
Zherikhinina tola Krzemińska, Krzemiński & Dahl 2009a Lower Cretaceous Onokhoy, Mongolia
Zherikhinina zherikhini Krzemińska, Krzemiński & Dahl 2009a Upper Jurassic Karatau, Kazakhstan

The specimens for this study were collected from the Jiulongshan Formation of the Daohugou Village in Inner Mongolia, China. The Daohugou fossil-bearing beds are considered as the late Middle Jurassic (Bathonian-Callovian boundary, 165 Mya) (Ren et al. 2002; Gao and Ren 2006; Ren et al. 2010a; Shi et al. 2011). Daohugou is one of the localities where the fossils of Yanliao biota were distributed. A huge number of fossil insects have been reported (Ren and Engel 2007; Engel and Ren 2008; Liu and Ren 2008; Ren et al. 2009; Wang and Ren 2009; Gu et al. 2010; Ren et al. 2010b; Wang et al. 2010; Wang et al. 2012; Yang et al. 2012).

Materials and methods

The wing venation nomenclature used in this paper is based on the interpretations and system proposed by Lukashevich (2004) and Krzemińska et al. (2009a). The fossil specimens were examined under a Leica MZ7.5 dissecting microscope and illustrated with the aid of a drawing tube attachment. Line drawings were prepared with Adobe Photoshop CS3 Extended graphics software.

All specimens studied in the paper are housed in the Key Lab of Insect Evolution and Environmental Changes, College of Life Sciences, Capital Normal University, Beijing, China.

Systematic paleontology
Family Trichoceridae Kertész, 1902 Genus Eotrichocera Kalugina, 1985
Subgenus Archaeotrichocera Krzemińska, Krzemiński & Dahl, 2009
Type species.

Eotrichocera (Archaeotrichocera) ephemera Zhang, 2006

Other included species.

Eotrichocera (Archaeotrichocera) conica Krzemińska, Krzemiński & Ren, 2009; Eotrichocera (Archaeotrichocera) rara Krzemińska, Krzemiński & Ren, 2009; Eotrichocera (Archaeotrichocera) spatiosa Liu, Shih & Ren, 2012.

Key to the species of Eotrichocera (Archaeotrichocera)
1 Sc ending at anterior margin distad of R2 2
Sc ending at anterior margin proximad of R2 3
2 Large size (wing length 12.0 mm) Eotrichocera (Archaeotrichocera) spatiosa Liu, shih & Ren, 2012 (Daohugou, J2)
Medium size (wing length 5.5 mm) Eotrichocera (Archaeotrichocera) rara Krzemińska, Krzemiński & Ren, 2009 (Daohugou, J2)
3 Crossvein sc-r distad of 1/2 (at 2/3) of length of Rs 4
Crossvein sc-r proximad of or at 1/3 of length of Rs 5
4 Rs forking distad of 2/3 (at 0.77) times of wing length Eotrichocera (Archaeotrichocera) ephemera Zhang, 2006 (Daohugou, J2)
Rs forking proximad of 2/3 (at about 0.53) times of wing length Eotrichocera (Archaeotrichocera) longensis sp. n. (Daohugou, J2)
5 A2 long (0.22 times as long as wing), d cell narrow and long (W/L=0.43 Eotrichocera (Archaeotrichocera) conica Krzemińska, Krzemiński & Ren, 2009 (Daohugou, J2)
A2 short (0.13 times as long as wing), d cell broad (W/L=0.58) Eotrichocera (Archaeotrichocera) amabilis sp. n. (Daohugou, J2)
Etymology.

longensis” is a Latin word, referring to the long leg of this specimen.

Diagnosis.

Sc rather short about 0.65 times as long as the wing and ending at anterior margin proximad of R2; Rs forking proximad of 2/3 (at about 0.55) times of wing length; the d-cell narrow and long (about 2.5 times as long as wide); A2 short and bending sharply toward anterior margin (angle about 128°).

Holotype.

An almost complete female specimen with well-preserved body, wings and head. Specimen number CNU-DIP-NN2013133. Wing length 9.0 mm, width 3.8 mm (Figs 1A, 2, 3A).

Figure 1.

Eotrichocera (Archaeotrichocera) longensis sp. n. Holotype, specimen CNU-DIP-NN2013133 A Photograph. Paratype, specimen CNU-DIP-NN2013131 B Photograph. Scale bars = 1 mm.

Figure 2.

Eotrichocera (Archaeotrichocera) longensis sp. n. Holotype, specimen CNU-DIP-NN2013133 A Line drawing B Tarsus of the mid leg. Scale bars = 1 mm; t1 = the first segment of tarsus; t2 = the second segment of tarsus; t3 = the third segment of tarsus; t4 = the fourth segment of tarsus.

Figure 3.

Eotrichocera (Archaeotrichocera) longensis sp. n. Holotype, specimen CNU-DIP-NN2013133 A Line drawing of left wing. Paratype, specimen CNU-DIP-NN2013131 B Line drawing of left wing. Scale bars = 1 mm

Paratype.

A female specimen with body and wings, specimen number CNU-DIP-NN2013131. Wing length 7.7 mm, width 3 mm (Figs 1B, 3B).

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-NN2013131 in brackets. Medium-sized winter crane flies, body length (including head) 13 mm with well preserved wings, body and head, [paratype body length (excluding head) 10.5 mm].

Head: Antenna very long, about 3.5 times as long as the head length, palpi about two times as long as the head length, compound eyes preserved.

Thorax: Much higher, in lateral view, than that of the abdomen, subcircular in shape, with robust and well-developed mesonotum. The halters spoon-type and the length of halters as long as thorax.

Wings: Wing is shorter than abdomen, not covering the end of the abdomen. Length 9.0 mm [Paratype with wing length of 7.7 mm], narrow and long (about 2.5 times as long as wide); venation clear, Sc rather short about 0.68 times as long as the wing [Paratype Sc rather short, about 0.65 times as long as the wing] and ending at anterior margin proximad of R2; crossvein sc-r locating at 2/3 of Rs; Rs arising about one-fifth from the base of the wing; R2+3 about 0.8 times as long as R2+3+4; R2 about one-tenth of length of R3; R3 almost three times as long as the R2+3; dM1+2 0.6 times as long as mM1+2, while M1 2.5 times of the dM1+2; a well developed m-m crossvein about three-fourth length of bM3, closing the d-cell and nearly 0.3 length of d-cell; bM1+2 nearly 1.0 times as long as the length of the r-m and the latter at one-fifth of the d-cell; d-cell narrow and long (about 2.5 times as long as wide) and almost one-fifth length of wing; both crossveins m-m and m-cu intersecting with M4 at the same point; Cu long, curved (angle about 135°) and reaching the wing posterior margin at 0.6 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, 0.15 (right wing) [Paratype 0.14] times as long as wing and almost 0.3 times as long as length of A1, bending sharply (angle about 128°) and reaching the wing posterior margin.

Legs: Legs slender and long; the hind leg nearly 1.2 times as long as the abdomen and 1.3 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.

Abdomen: Abdomen relatively long and thin, with ten segments. Female genital discernible.

Remarks.

Eotrichocera (Archaeotrichocera) longensis sp. n. is assigned to Thrichocerinae based on the following characters: d-cell medium, m-cu present; A2 short, antennae long, flagellomeres thin, much longer than two times of the head length. It belongs to Eotrichocera (Archaeotrichocera) because of wing length from 7.7 to 9.0 mm and d-cell almost one-fifth of wing length. In addition, it differs from all other known Thrichocerinae by its A2 rather short and bending sharply toward anterior margin (angle about 128°), R2 relatively long, Sc forking proximad of 2/3 (at about 0.55) times of wing length, and d-cell narrow and long. To compare the key characters among the new species and other species of Eotrichocera (Archaeotrichocera), we set up the Table 2.

Table 2.

Comparison of key characters among the two new species and other species of Eotrichocera (Archaeotrichocera) Krzemińska, Krzemiński & Dahl, 2009. L/W = ratio of length/width; W/L = ratio of width/length.

Key characters Eotrichocera (Archaeotrichocera) ephemera Zhang, 2006 Eotrichocera (Archaeotrichocera) conica Krzemińska, Krzemiński & Ren, 2009 Eotrichocera (Archaeotrichocera) rara Krzemińska, Krzemiński & Ren, 2009 Eotrichocera (Archaeotrichocera) spatiosa Liu, Shih & Ren, 2012 Eotrichocera (Archaeotrichocera) longensis sp. n. Eotrichocera (Archaeotrichocera) amabilis sp. n.
Wing length, in mm and (L/W) 7.1 (L/W=2.8) 10.0 (L/W=3) 5.5 12.0 (L/W=2.7) 9.0 (L/W=2.3) 5.2 (L/W=2.2)
Sc length and ending at anterior margin 0.77 times of wing length, ending proximad of R2 0.71 times of wing length, ending proximad of R2 0.77 times of wing length, ending distad of R2 0.84 times of wing length, and ending distad of R2 about 0.65 times of wing length, ending proximad of R2 about 0.71 times of wing length, ending proximad of R2
sc-r position at 2/3 of length of Rs at 1/3 of length of Rs at 1/2 of length of Rs at 2/3 of length of Rs at 2/3 of length of Rs at 1/3 of length of Rs
Position of Rs forking 0.77 times of wing length 0.64 times of wing length 0.57 times of wing length 0.58 times of wing length 0.53 times of wing length 0.55 times of wing length
d-cell W/L (length) W/L=0.53 (1/6 of wing length) W/L=0.43 (0.2 times of wing length) W/L=0.39 (0.21 times of wing length) W/L=0.47 (0.19 times of wing length) W/L= 0.4 (almost 1/5 of wing length) W/L=0.58 (almost 0.17 of wing length)
A2 length long (about 1/4 of wing length), curved evenly to posterior margin medium (0.22 times of wing length), not reaching posterior margin rather short (1/5 of wing length) and not reaching posterior margin short (about 0.21 times of wing length) and curving to posterior margin short (0.14) times of wing length) and curved to posterior margin short (0.13) times of wing length) and curved to posterior margin
r-m length ....... 1/5 of length of d-cell ....... about 1/3 of length of d-cell 1/5 of length of the d-cell 0.24 or 0.15 of length of the d-cell
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 4A–D, 5A, 6).

Figure 4.

Eotrichocera (Archaeotrichocera) amabilis sp. n. Holotype, specimen CNU-DIP-NN2013134 A Photograph B Photograph, under alcohol C Line drawing D Tarsus of the mid leg. Paratype, specimen CNU-DIP-NN2013132 E Photograph. Scale bars = 1 mm; t1 = the first segment of tarsus; t2 = the second segment of tarsus.

Figure 5.

Eotrichocera (Archaeotrichocera) amabilis sp. n. Holotype, specimen CNU-DIP-NN2013134 A Line drawing of left wing. Paratype, specimen CNU-DIP-NN2013132 B Line drawing of left wing. Scale bars = 1 mm.

Figure 6.

Eotrichocera (Archaeotrichocera) amabilis sp. n. Holotype, specimen CNU-DIP-NN2013134, Photograph of head, under alcohol. Scale bar = 1 mm.

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 4A–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.

Acknowledgements

We sincerely appreciate valuable comments and constructive suggestion from Dr. Ewa Krzemińska. We thank Dr. Wang Y-J, Dr. Gao T-P, Shi C-F, Peng Y-Y and Li L-F, Shi G-F for their helpful comments, fruitful suggestion and improvement of our manuscript. This research was supported by grants from the National Basic Research Program of China (973 Program) (Grant 2012CB821906), the National Nature Science Foundation of China (No. 31230065, 41272006), Great Wall Scholar and KEY project of Beijing Municipal Commission of Education (Grant KZ201310028033), Program for Changjiang Scholars and Innovative Research Team in University (IRT13081).

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