Research Article |
Corresponding author: Ren Dong ( rendong@mail.cnu.edu.cn ) Academic editor: Vladimir Blagoderov
© 2015 Xiuqin Lin, ChungKun Shih, Ren 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.
Citation:
Lin X, Shih C, Dong R (2015) Revision of the genus Epimesoplecia Zhang, 2007 (Diptera, Nematocera, Protopleciidae) with five new species. ZooKeys 492: 123-143. https://doi.org/10.3897/zookeys.492.6852
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The genus Epimesoplecia Zhang, 2007 of Protopleciidae is revised based on five new species, E. plethora sp. n., E. prosoneura sp. n., E. stana sp. n., E. macrostrena sp. n., and E. ambloneura sp. n., described and illustrated from the Jiulongshan Formation of China. These new species, with clearly preserved characters of (1) compound eyes connected in males; (2) antennae, filiform or moniliform, with 16 segments; (3) r-m reaching the middle of the wing; (4) R4+5 ending very close to wing apex; (5) ratio of bRs/dRs ranging from 1.6 to 10.5; (6) M2 more than 3 times as long as dM1+2; (7) legs thin and long, femur slender, almost equal to tibia; (8) tibial spurs minute; and (9) male genitalia (previously unknown), enable us to emend the diagnosis of Epimesoplecia Zhang, 2007. In addition, all described species of Epimesoplecia are characterized, their features summarized, and a key to Epimesoplecia species is given.
Insects, fossil, taxonomy, Jiulongshan Formation, late Middle Jurassic
Protopleciidae Rohdendorf, 1946, reported from the Jurassic, is a paraphyletic stem group to the Bibionidae (
Herein, based on fourteen specimens collected from the Jiulongshan Formation in Daohugou Village, Ningcheng County, Inner Mongolia, China, five new species are described in Epimesoplecia, E. plethora sp. n., E. prosoneura sp. n., E. stana sp. n., E. macrostrena sp. n., and E. ambloneura sp. n. with ten specimens. One of the remaining four specimens is identified as a new material for E. elenae Zhang, 2007, while the other three cannot be assigned to species owing to lack of preserved diagnostic characters. These five new species are assigned to Epimesoplecia by a combination of the following characters: (1) antenna long, at least twice the head length; (2) wing narrow and long; (3) Sc elongate, nearly half of wing length; (4) R2+3 long, more than two–thirds of R4+5 length.
The Jiulongshan Formation of Inner Mongolia in China is very rich in fossil insects’ record (
All the type materials were collected from the Jiulongshan Formation (Fig.
Epimesoplecia shcherbakovi Zhang, 2007
Type species, E. elenae Zhang, 2007, E. plethora sp. n., E. prosoneura sp. n., E. stana sp. n., E. macrostrena sp. n. and E. ambloneura sp. n.
Compound eyes connected in males. Antennae filiform or moniliform, with 16 segments, at least twice of head length or slightly less than twice of head length; wings narrow and long; Sc elongate, at or near the same level of r-m; bRs at least 4 times as long as r-m; R2+3 long, more than two-thirds of R4+5, R2+3 slightly sigmoidly curved or straight, reaching anterior margin distad of the apex of R1; r-m reaching the middle of the wing; R4+5 ending very close to wing apex; M1+2 furcated distinctly proximad or distad of R2+3; M2 more than 3 times as long as dM1+2; bM3+4 longer or slightly shorter than m-cu; pterostigma absent; bM1+2 longer or shorter than dM1+2. Legs thin and long, femur slender, almost equal to tibia; tibial spurs minute. Male genitalia: abdomen cylindrical; genitalia complex, narrower than the 8th segment, with gonocoxites rounded; gonostylus elongated, shorter than gonocoxites. Female genitalia: the 8th segment smaller than preceding segments, genitalia simple, with 2-segmented cerci, the basal segment of cerci longer than the terminal one.
The epithet of plethora is derived from the Greek word “plethore”, meaning “fullness”, emphasizing the body covered with dense pubescence. The specific epithet is a noun in apposition.
Compound eyes crescent. Antennae moniliform. Sc very close to the level of r-m; fork of Rs distad of fork of M1+2; Rs distad of crossvein r-m; bRs less than 2 times (1.6–1.8) as long as dRs, the latter about 3 times (2.6–3) as long as r-m; R2+3, sigmoidly curved, distinctly shorter than bRs and dRs combined; bM1+2 shorter than dM1+2; bM3+4 shorter than m-cu; cell bp as wide as cell ba terminally.
Holotype: Female. NO. CNU-DIP-NN2013202, a well-preserved almost complete body with left haltere, both wings and part of legs (Fig.
All specimens were collected from the Jiulongshan Formation, late Middle Jurassic age (Late Callovian) from Daohugou Village, Ningcheng County, Inner Mongolia Autonomous Region in China.
Head (Fig.
Thorax (Figs
Legs (Figs
Wings (Figs
Female genitalia (Fig.
(in mm). [Measurements for the paratype CNU-DIP-NN2013209p/c in brackets, if different]. Holotype: female. CNU-DIP-NN2013202, Body length 10 [5 as preserved], maximal width of body 2.2 [2.4]. Head length 0.6, width 0.8. Forelegs: femur 1.7 as preserved [2.2]; tibia 1.4 as preserved [3.4]. Mid legs: femur 3 [2.8], tibia 3.5 [3]. Hind legs: femur 3.6 [4], tibia 4.4 [5]. Wing: length 9.0 [8.2], width 3.4 [3.0], R2+3 2.4, bRs 2.2 [2.1], dRs 1.2, R4+5 3 [3.4].
The new species is differentiated from E. shcherbakovi Zhang, 2007 by the following features: bRs less than 2 times (1.6–1.7) as long as dRs (vs. bRs 4.5 times as long as dRs); Rs bifurcation distad to fork of M1+2 (vs. Rs bifurcation at the same level of fork of M1+2); dM1+2 longer than bM1+2 (vs. dM1+2 shorter than bM1+2). The new species differs from E. elenae Zhang, 2007 in having antennae moniliform (vs. filiform); bRs short, less than 2 times (1.6–1.7) as long as dRs (vs. bRs long, 2.5 times as long as dRs); bM3+4 clearly shorter than m-cu (vs. bM3+4 as long as m-cu). Comparisons with other species are listed in Table
Species | Specimen numbers | H/P | Sex | BL | WL | L/W | bRs/dRs | dRs/r-m | bM1+2/dM1+2 | M2/dM1+2 | bM3+4/m-cu | bRs/r-m | Rs vs. M1+2 |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
E. plethora sp. n. | CNU-DIP-NN2013202 | H | ♀ | 10.6 | 9 | 2.6 | 1.6 | 2.6 | 0.6 | 4.2 | shorter | 4 | DS |
CNU-DIP-NN2013209 p/c | P | NA | 5 (ic) | 8.4 | 2.8 | 1.75 | 3 | 0.8 | 6 | NA | 5 | DS | |
E. prosoneura sp. n. | CNU-DIP-NN2013207 p/c | H | ♂ | 8.3 | 8 | 3.1 | 10.5 | 0.3 | 0.4 | 4.2 | shorter | 4.8 | PX |
CNU-DIP-NN2013214 | A | ♀ | 8.2 | 8.9 | 3.3 | 9.4 | 0.6 | 0.8 | 5.2 | shorter | 5.8 | PX | |
E. stana sp. n. | CNU-DIP-NN2013201 p/c | H | ♀ | 10.2 | 11.2 | 3.3 | 2.5 | 2 | 2.3 | 8 | shorter | 5.4 | DS |
E. shcherbakovi Zhang, 2007 | DHG200384 | H | NA | 7 (ic) | 9.7 | 2.7 | 4.5 | 0.9 | 1.5 | 5 | longer | 4.6 | SL |
E. elenae Zhang, 2007 | DHG200385 | H | ♀ | 10.5 | 10 | 2.4 | 2.5 | 1.8 | 0.6 | 5 | shorter | 4 | DS |
CNU-DIP-NN2013213 p/c | N | ♀ | 11.2 | 7.6 | 2.5 | 2.7 | 1.7 | 0.5 | 5.6 | shorter | 4.6 | DS | |
E. macrostrena sp. n. | CNU-DIP-NN2013211 | H | NA | 9(ic) | 7.4(ic) | >3 | 5 | 1.1 | 0.7 | ≈3 | NA | 5.6 | PX |
CNU-DIP-NN2013212 | P | ♀ | 10.3 | 7.1 | 2.5 | 4.7 | 1.1 | 0.7 | 3 | shorter | 4.6 | PX | |
CNU-DIP-NN2013206 p/c | P | NA | 7 (ic) | 8 | 3.5 | 4.2 | 1.2 | 0.7 | 6.2 | longer | 4.4 | PX | |
E. ambloneura sp. n. | CNU-DIP-NN2013215 | H | ♀ | 12.7 | 9.1 | 2.5 | 7 | 0.7 | 2.8 | 11 | shorter | 5 | SL |
CNU-DIP-NN2013208 | P | NA | 5 (ic) | 7.4 | 2.3 | 6 | 0.7 | 1.3 | 8 | shorter | 5 | SL |
The epithet of prosoneura is derived from the Greek preposition “pro”, meaning “before”, and Greek word “neura”, meaning “string or sinew”, referring to proximal position of the fork of Rs. The specific epithet is a noun in apposition.
Compound eyes crescent. Antennae moniliform. Sc exceeding the level of r-m or very close to r-m; fork of Rs proximad of fork of M1+2; R2+3 very close to crossvein r-m; R2+3, almost straight, distinctly longer than bRs and dRs combined; bRs about 10 times (9.4–10.5) as long as dRs, the latter as long as r-m; bM1+2 shorter than dM1+2; bM3+4 shorter than m-cu; cell bp wider than cell ba terminally.
Holotype: male, NO. CNU-DIP-NN2013207p/c, part and counterpart, an almost complete specimen with well-preserved antennae, both wings and part of legs (Fig.
Epimesoplecia prosoneura sp. n. (CNU-DIP-NN2013207p/c). Holotype. Photographs of A, B Part and counterpart C Details of head (under alcohol) D Details of male genitalia (under alcohol); Line drawings of E Counterpart F Head G Male genitalia H Wing. Scale bars = 1 mm. gc–gonocoxite; gs–gonostylus.
All specimens were collected from the Jiulongshan Formation, late Middle Jurassic age (Late Callovian) from Daohugou Village, Ningcheng County, Inner Mongolia Autonomous Region in China.
Head (Figs
Thorax (Figs
Legs (Figs
Wings (Figs
Male genitalia (Fig.
Female genitalia (Fig.
(in mm). [Measurements for the paratype CNU-DIP-NN2013214 in brackets, if different]. Holotype: male, CNU-DIP-NN2013207p/c, Body length 9.3 [8.2], maximal width of body 1.6 [1.4]. Antennae length: 1.8 (segments 1–16) [1.4 (segments 1–15)]. Foreleg: femur 1.6 as preserved; tibia 2.5 as preserved. Mid leg: femur 1.9 as preserved; tibia 2.7 as preserved. Hind leg: femur 2.2 as preserved [2 as preserved], tibia 3.5 as preserved [1.3 as preserved]. Wing: length 8 [8.9], width 2.6 [2.7]; R2+3 3 [3.7]; bRs 1.9 [2.3]; dRs 0.1 [0.3]; R4+5 3.6 [4].
The new species is similar to E. shcherbakovi Zhang, 2007 but differs from the latter in having bRs about 10 times (9.4–10.5) as long as dRs (vs. 4.5 times); Rs bifurcation proximad of fork of M1+2 (vs. Rs bifurcation at the same level of fork of M1+2); dM1+2 longer than bM1+2 (vs. dM1+2 shorter than bM1+2); R2+3, very close to the position crossvein r-m, distinctly longer than bRs and dRs combined (vs. R2+3, distad of the position crossvein r-m, clearly shorter than bRs and dRs combined). The new species differs from E. plethora sp. n. in having bRs about 10 times (9.4–10.5) as long as dRs (vs. less than 2 times); bM3+4 clearly shorter than m-cu (vs. bM3+4 shorter than m-cu); Rs bifurcation proximad of fork of M1+2 (vs. Rs bifurcation distad of fork of M1+2); dRs distinctly shorter than r-m (vs. dRs about 3 times as long as r-m); R2+3, very close to the position crossvein r-m, distinctly longer than bRs and dRs combined (vs. R2+3, sigmoidly curved, distinctly shorter than bRs and dRs combined). Comparisons with other species are listed in Table
The epithet is an arbitrary combination of letters used as a nun in apposition.
Antennae moniliform. Sc very close to the level of r-m; fork of Rs distad of fork of M1+2; R2+3 distad of crossvein r-m; R2+3, straight, distinctly less than bRs and dRs combined; bRs 2.5 times as long as dRs, the latter 2 times as long as r-m; bM1+2 significantly longer than dM1+2 (2.3 times); bM3+4 slightly longer than m-cu; cell bp narrower than cell ba terminally.
Holotype: female, NO. CNU-DIP-NN-2013201p/c, in lateral view, a well-preserved body with partial antennae, almost complete wings and legs.
The specimen was collected from the Jiulongshan Formation, late Middle Jurassic age (Late Callovian) from Daohugou Village, Ningcheng County, Inner Mongolia Autonomous Region in China.
Head (Fig.
Thorax (Fig.
Legs (Fig.
Wings (Fig.
Female genitalia (Fig.
(in mm). Holotype: female, CNU-DIP-NN2013201p/c, Body length 10.2, maximal width of body 2.2. Antennae 1.1 (segments 1–11). Foreleg: femur 2.5; tibia 2.7. Mid leg: femur 3; tibia 3.4. Hind leg: femur 3.7, tibia 3.4. Wing: length 11.2, width 3.4; R2+3 3; bRs 2.5; dRs 1.1; R4+5 3.7.
The new species having ratio of bRs/dRs of 2.5 is similar to E. elenae Zhang, 2007, but is distinguished from the latter by having Rs bifurcation significantly distad of fork of M1+2 (vs. Rs bifurcation slightly distad of fork of M1+2); bM1+2 distinctly longer than dM1+2 (vs. bM1+2 clearly shorter than dM1+2); dM1+2 clearly shorter than r-m (vs. dM1+2 as long as r-m); dM1+2 short, almost one-eighth of M2 (vs. dM1+2 long, one-fifth of M2). Comparisons with other species are listed in Table
The epithet of macrostrena is derived from the Greek prefix “macro-”, meaning “large”, and Greek word “strenos”, meaning “insolence or excess of strength”, referring to the large wings and strong body of this species. The specific epithet is a noun in apposition.
Antennae filiform. Sc very close to the level of r-m; fork of Rs proximad of fork of M1+2; R2+3 distad of crossvein r-m; R2+3, straight, slightly shorter than bRs and dRs combined; bRs about 5 times (4.2–5) as long as dRs, the latter almost equal to r-m; bM1+2 shorter than dM1+2 (0.7 times); bM3+4 shorter than m-cu (barely longer than m-cu); cell bp slightly wider than cell ba terminally.
Holotype: sex unknown. NO. CNU-DIP-NN-2013211, in lateral view, a well-preserved specimen with partial antennae, wings and body as preserved (Fig.
All specimens were collected from the Jiulongshan Formation, late Middle Jurassic age (Late Callovian) from Daohugou Village, Ningcheng County, Inner Mongolia Autonomous Region in China.
Head (Figs
Thorax (Figs
Legs (Figs
Wings (Figs
Female genitalia (Fig.
(in mm). [Measurements for the holotype in brackets]. Body length 7 (as preserved)–11.3 [10.3 as preserved]; antennae 0.9 (as preserved)–1.4 (segments 1–16) [0.9 segments 1–9]. Forelegs: femur 2.1–2.5 [1.8 as preserved]; tibia 2.9–3.1 [2.7 as preserved]. Mid leg: femur 2.4–3.8 as preserved [3.8 as preserved]; tibia 2.7–3.6 as preserved [3.6 as preserved]. Hind leg: femur 3.4–4.7 [4.7], tibia 3.8–4.8 [4.8]. Wing: length 7.1–8 [7.4 as preserved], width 2.3–3.3 [3.3]; R2+3 2.4–3.2 [3.2]; bRs 1.9–2.9 [2.9]; dRs 0.5–0.8 [0.6]; R4+5 3–3.7 [3.7].
The new species is similar to E. shcherbakovi Zhang, 2007, but is differentiated from the latter by having Rs bifurcation proximad of fork of M1+2 (vs. Rs bifurcation at the same level of fork of M1+2); bM1+2 shorter than dM1+2 (vs. bM1+2 longer than dM1+2); dRs as long as r-m (vs. dRs clearly shorter than r-m); dM1+2 long, almost one-third of M2 (vs. dM1+2 short, significantly less than one-third of M2). Comparisons with other species are listed in Table
The epithet of ambloneura is derived from the Greek prefix “ambl-”, meaning “obtuse”, and Greek word “neura”, meaning “string or sinew”, referring to the blunt caudal vein of this species. The specific epithet is a noun in apposition.
Antennae filiform. Sc very close to the level of r-m; fork of Rs at the same level of fork of M1+2; R2+3 proximad of crossvein r-m; R2+3, straight, distinctly longer than bRs and dRs combined; bRs about 6–7 times as long as dRs, the latter clearly shorter than r-m; bM1+2 significantly longer than dM1+2 (1.3–2.8 times); M2 8–11 times as long as dM1+2; bM3+4 shorter than m-cu; cell bp slightly wider than cell ba terminally.
Holotype: male. NO. CNU-DIP-NN-2013215, in ventral view, a well-preserved specimen with partial antennae, complete wings and body (Fig.
All specimens were collected from the Jiulongshan Formation, late Middle Jurassic age (Late Callovian) from Daohugou Village, Ningcheng County, Inner Mongolia Autonomous Region in China.
Head (Fig.
Thorax (Figs
Legs (Fig.
Wings (Figs
Female genitalia (Fig.
(in mm). [Measurements for the paratype, CNU-DIP-NN2013208 in brackets]. Holotype: male. NO. CNU-DIP-NN-2013215, body length 12.7 as preserved [5 as preserved]; antennae 1.5 as preserved. Forelegs: femur 3.5 as preserved; tibia 3.9. Mid leg: femur 3.9; tibia 4.2. Hind leg: femur 4.2, tibia 4.8. Wing: length 9.1 [7.4], width 3.6 [3.2]; R2+3 3.5 [2.9]; bRs 2.5 [1.9]; dRs 0.35 [0.3]; R4+5 4 [3.3].
The new species is similar to E. shcherbakovi Zhang, 2007, but differs from the latter in having bRs about 6–7 times as long as dRs (vs. 4.5 times); R2+3 clearly longer than bRs and dRs combined (vs. R2+3 significantly shorter than bRs and dRs combined); Rs bifurcation proximad of r-m (vs. Rs distad of r-m); M2 8–11 times as long as dM1+2 (vs. 5 times); bM3+4 shorter than m-cu (vs. bM3+4 longer than m-cu). Comparisons with other species are listed in Table
1 | Fork of Rs proximad fork of M1+2 | 2 |
– | Fork of Rs distad or at same level fork of M1+2 | 3 |
2 | Fork of Rs proximad of r-m; bRs about 10 times as long as dRs | E. prosoneura sp. n. |
– | Fork of Rs distad of r-m; bRs significantly less than 10 times as long as dRs | E. macrostrena sp. n. |
3 | Fork of Rs at the same level of M1+2; dRs shorter than r-m | 4 |
– | Fork of Rs distad of M1+2; dRs longer than r-m | 5 |
4 | R2+3 longer than Rs; bM1+2 clearly shorter than m-cu | E. ambloneura sp. n. |
– | R2+3 distinctly shorter than Rs; bM1+2 longer than m-cu | E. shcherbakovi Zhang, 2007 |
5 | bM1+2 longer than dM1+2 | E. stana sp. n. |
– | bM1+2 distinctly shorter than dM1+2 | 6 |
6 | Antennae moniliform; bRs significantly less than 2.5 times as long as dRs | E. plethora sp. n. |
– | Antennae filiform; bRs 2.5 times as long as dRs | E. elenae Zhang, 2007 |
The generic diagnosis of Epimesoplecia Zhang, 2007 is revised based on eleven well-preserved new specimens, among which ten are used to describe the afore-mentioned five new species. One is identified as a new material for E. elenae Zhang, 2007 (Fig.
It is interesting to note that only one of the 13 specimens reported so far is male, ie. the holotype of E. prosoneura sp. n. (CNU-DIP-NN2013207 p/c) with well-preserved male genitalia. We also describe a female paratype of E. prosoneura sp. n. (CNU-DIP-NN2013214) with well-preserved female genitalia. Since both specimens have similar body size, wing length and venational characters, the sexual dimorphism of this species seems to be not significant.
The measurements of body length, wing length and other important characters of wings are summarised in Table
We sincerely appreciate comments and suggestion from Dr. Vladimir Blagoderov and two anonymous reviewers in improving this manuscript. We are grateful to Dr. Gao Taiping, Li Longfeng and Peng Yuanyuan for their constructive and critical comments on the manuscript. This research was supported by the National Basic Research Program of China (973 Program) (No. 2012CB821906), the National Natural Science Foundation of China (Nos. 31230065 and 41272006), Great Wall Scholar and KEY project of Beijing Municipal Commission of Education (KZ201310028033) and Program for Changjiang Scholars and Innovative Research Team in University (IRT13081).