Two new species of Trichoceridae from the Middle Jurassic Jiulongshan Formation of Inner Mongolia, China.

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.

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 ) 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: Scudder, 1894; Kalugina, 1985; Krzemińska, Krzemiński & Dahl, 2009; Kalugina, 1985; Kalugina, 1986; Krzemińska, Krzemiński, Dahl & Lukashevich, 2009; Meigen, 1803; Zhang, 2006; Krzemińska, Krzemiński & Dahl, 2009; Krzemińska, Krzemiński & Dahl, 2009; Krzemińska, Krzemiński & Dahl, 2009; Brunetti, 1911 (Krzemińska et al. 2009a). The oldest species of trichocerids, , and 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: Zhang, 2006; Zhang, 2006; Zhang, 2006; Zhang, 2006; Krzemińska, Krzemiński & Ren, 2009; Krzemińska, Krzemiński & Ren, 2009; Liu, Shih & Ren, 2012 and Krzemińska, Krzemiński & Dahl, 2009.

Furthermore, Zhang, 2006 has been changed as a subgenus belonging to ; Dahl, 1971 as a subgenus belonging to Podenas, 2001; Kalugina, 1986 and 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 Kalugina, 1985

Krzemińska, Krzemiński & Dahl, 2009

Type species.

Zhang, 2006

Other included species.

Krzemińska, Krzemiński & Ren, 2009; Krzemińska, Krzemiński & Ren, 2009; Liu, Shih & Ren, 2012.

sp. n.

http://zoobank.org/8A0D358E-7BCA-476B-A0A9-6EECA93FCBA8

http://species-id.net/wiki/Eotrichocera_longensis

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.

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

Figure 2.

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.

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.

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 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 , we set up the Table 2.

Table 2.

Comparison of key characters among the two new species and other species of 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

http://zoobank.org/D32A4E4B-EDF1-4684-802E-92F9617DEAB2

http://species-id.net/wiki/Eotrichocera_amabilis

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

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°).

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.

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.

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.

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

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

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

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.

The new species is compared and differentiated from all other species in 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 . These characters may help future morphological and taxonomic studies in differentiating fossil species of Trichoceridae.

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)