Research Article |
Corresponding author: Mei Wang ( wangmeicnu@163.com ) Academic editor: Michael S. Engel
© 2016 Chen Wang, ChungKun Shih, Alexandr P. Rasnitsyn, Mei Wang.
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:
Wang C, Shih C, Rasnitsyn AP, Wang M (2016) Two new species of Prolyda from the Middle Jurassic of China (Hymenoptera, Pamphilioidea). ZooKeys 569: 71-80. https://doi.org/10.3897/zookeys.569.7249
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Two new species of the genus Prolyda Rasnitsyn, 1968, Prolyda dimidia sp. n. and Prolyda elegantula sp. n., are described and illustrated. Both specimens were well-preserved and collected from the latest Middle Jurassic Jiulongshan Formation of Daohugou Village in Inner Mongolia, China. Based on the new morphological data, a key to the five known species of Prolyda is provided. In addition, Prolyda has an enlarged first antennal flagellomere, which means it might have revert to the elongate plesiomorphic state for the antennal configuration as previously documented.
Daohugou, fossil insect, Jiulongshan Formation, sawfly, taxonomy
Xyelydidae have long been regarded as the basal group of the Pamphilioidea (
A total of 12 genera and 30 species of xyelydids has been reported to date (table 1 in
The Yanliao biota at the Daohugou site has become well known because of the recent discoveries and reports from this locality a variety of excellently-preserved insects, plants, and other animals (
Both type specimens are deposited in the Key Laboratory of Insect Evolution and Environmental Changes, College of Life Sciences, Capital Normal University, Beijing, China (CNUB; Dong Ren, Curator).
The specimens were examined and photographed, either dry or moistened with 95% ethanol, with a Leica DFC500 digital camera attached to a Leica MZ165C dissecting microscope (Leica, Wetzlar, Germany). The wing venation nomenclature used in this study is modified from
Prolyda karatavica Rasnitsyn, 1968
P. depressa Rasnitsyn, 1969, P. xyelocera Rasnitsyn, 1968, P. dimidia sp. n., and P. elegantula sp. n.
Head massive, circular or cube-like; mandibles curved, strong and sickle-like; pronotum short and wide; the first antennal flagellomere equal to head in length, but eight times as long as the second flagellomere; forewing pterostigma variable, completely sclerotized or partly sclerotized, or just membranous; M diverging from M+Cu at much larger angle than Cu; 1-RS proclival or somewhat vertical; angle between 1-M and RS+M almost 90°; 1cu-a distal to the middle of cell 1mcu or located at middle; 2r-rs almost in line with 2r-m; hind wing with 1r-m rather long, as long as or slightly shorter than 1-M.
In addition to generic diagnosis, SC1 longer than SC2; SC2 relatively long, almost equal to 1-RS in length; 1-M short, about twice as long as 1-RS, and 0.6 times as long as RS+M; 2r-m slightly postfurcal; 1r-rs vertical, slightly shorter than 2r-rs and parallel to it; 3r-m located well distal to middle of cell 3r, separated from apex of cell 3r by almost its own length; 2m-cu at middle of cell 3rm.
(in mm). Body length (excluding antenna) 11.4, head length including mandible 2.03, width 2.48, forewing length up to the end of cell 3r 8.92, hind wing length up to the end of cell r 6.58.
Color not reliably known because of absence of counterpart (Fig.
Head circular and large (Fig.
Three pairs of legs preserved (Fig.
Forewing (Fig.
Hind wing (Fig.
Holotype, No. CNU-HYM-NN-2012147.
Jiulongshan Formation; Daohugou Village, Shantou Township, Ningcheng County, Inner Mongolia, China (41°18.979’N, 119°14.318’E); latest Middle Jurassic of the Bathonian-Callovian boundary.
The species epithet is derived from the Latin word “dimidius”, meaning half, referring to the pterostigma being more infuscate in the posterior half.
In addition to generic diagnosis, SC1 almost as long as SC2; 1-M long, about 0.8 times as long as RS+M; 2r-m well postfurcal; 1r-rs proclival and half as long as 2r-rs; 3r-m near apex of cell 3r, separated from apex of cell 3r by half of its length; cell 3rm widening towards apex; 2m-cu distal to middle of cell 3rm.
(in mm). Body length (excluding antenna) 12, head length including mandible 2.36, width 2.88, forewing length up to the end of cell 3r 7.02, hind wing length up to the end of cell r 4.8.
Color not reliably known because of absence of counterpart (Fig.
Head massive and wide (Fig.
Prothorax with propleura large and rectangular; as wide as mesoprescutum; mesonotum with median mesoscutellar sulcus and notauli present, mesoprescutum large, 0.4 times as long as mesonotum and 1.5 times as long as mesoscutellum; metanotum with metascutellum almost circular and metapostnotum rectangular, about 3.3 times as long as wide. Femora wide, fusiform and strong; hind femur about twice as wide as fore femur, and twice as wide as hind tibia; tibia covered with thick bristles (Fig.
Abdomen without tergum split, wider than mesonotum; abdominal segments narrow, and parallel-sided; anterior margin of the first segment incurved. Genitalia not preserved.
Forewing (Fig.
Holotype, No. CNU-HYM-NN-2012148.
Jiulongshan Formation; Daohugou Village, Shantou Township, Ningcheng County, Inner Mongolia, China (41°18.979’N, 119°14.318’E); latest Middle Jurassic of the Bathonian-Callovian boundary.
The species epithet is derived from the Latin word “elegantulus”, meaning graceful, referring to the habitus of this well preserved specimen.
1 | Forewing with 2r-m and 2r-rs aligned | 2 |
– | Forewing with 2r-m distal to 2r-rs | 3 |
2 | Pterostigma completely sclerotized; 2m-cu located distal to cell 3rm; cell 3rm widening toward wing apex | P. karatavica |
– | Pterostigma membranous basally and sclerotized apically; 2m-cu located at middle of cell 3rm, and cell 3rm not widened toward apex |
P. dimidia sp. n. (Fig. |
3 | Forewing with 2m-cu distal to middle of cell 3rm | 4 |
– | Forewing with 2m-cu proximal to middle of cell 3rm | P. depressa |
4 | 1-RS short, approx. 0.4 times as long as 1-M; RS+M twice as long as 2-M; pterostigma completely sclerotized |
P. elegantula sp. n. (Fig. |
– | 1-RS long, almost equal to 1-M in length; RS+M equal to 2-M in length; pterostigma partly sclerotized | P. xyelocera |
Prolyda were erected based on two species, P. karatavica and P. xyelocera (
Prolyda usually possesses a relatively large mesoprescutum, which is almost half the length of the mesonotum, and the mesoscutellum nearly reaches the posterior margin of mesoprescutum. Prolyda dimidia sp. n. and P. elegantula sp. n. do not have preserved antennae. However, as shown in P. karatavica and P. xyelocera, Prolyda are characterized by an enlarged first flagellomere, which is as long as the head and several times as long as the second flagellomere (
We particularly thank the Editor Dr Michael S. Engel and three reviewers (Dr Lars Vilhelmsen, Dr Zhiwei Liu and an anonymous reviewer) for their critical reviews, insightful comments and helpful editing of this article. Special thanks go to Dr Taiping Gao for his help and advice with this paper. This research was supported by the National Basic Research Program of China (973 Program; 2012CB821906), the National Natural Science Foundation of China (No. 31230065, 41272006), Great Wall Scholar of the Beijing Municipal Commission of Education (KZ201310028033), Program for Changjiang Scholars and Innovative Research Team in University (IRT13081). For APR, the work was additionally supported by the Presidium RAS Program “Origin and evolution of the geo-biological system”.