Research Article |
Corresponding author: Yongjie Wang ( wangyjosmy@gmail.com ) Academic editor: Shaun Winterton
© 2016 Bingyu Zheng, Dong Ren, Yongjie 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:
Zheng B, Ren D, Wang Y (2016) A new species of Lasiosmylus from the Early Cretaceous, China clarifies its genus-group placement in Ithonidae (Neuroptera). ZooKeys 636: 41-50. https://doi.org/10.3897/zookeys.636.10103
|
A new species, Lasiosmylus longus sp. n., is described from the Early Cretaceous Yixian Formation of Huangbanjigou Village, Liaoning Province, China. Based on the characters of the new species and nine new specimens of Lasiosmylus newi Ren & Guo, 1996, the generic diagnosis of Lasiosmylus is emended and the taxonomic position of Lasiosmylus Ren & Guo, 1996 is re-evaluated, and Lasiosmylus should be assigned to the ithonid genus-group.
Fossil, Huangbanjigou, ithonid genus-group, taxonomy, Yixian Formation
The genus Lasiosmylus Ren & Guo, 1996 was initially assigned to the subfamily Spilosmylinae in Osmylidae.
In this study a distinctive new species of Ithonidae, Lasiosmylus longus sp. n., is described from the Early Cretaceous of Yixian Formation, China. Additionally, nine new fossil specimens assignable to Lasiosmylus newi Ren & Guo, 1996 were collected from the same locality, which allow us to re-evaluate the systematic position of the genus within Ithonidae. Based on this new information, the genus Lasiosmylus is attributed to the ithonid genus-group and the diagnostic characters of Lasiosmylus are amended.
This study is based on ten specimens, which are deposited in the Key Lab of Insect Evolution and Environmental Change, Capital Normal University, Beijing, China. Draft drawings were produced using LEICA MZ75 dissecting microscope equipped with a drawing tube. Drawings were finalized using Adobe Illustrator CC. Photographs were taken by Leica Digital Camera DFC500 (Figs
The terminology of venation in general follows
Sc Subcosta
R1 first branch of Radius (R)
Rs Radial sector
MA anterior branches of Media (M)
MP posterior branches of Media
CuA anterior Cubitus (Cu)
CuP posterior Cubitus
1A–3A Anal veins
hp humeral plate
hv humeral veinlet
Lasiosmylus newi Ren & Guo, 1996.
Lasiosmylus newi Ren & Guo, 1996, Lasiosmylus longus sp. n.
Body stout (ca. 11–17 mm long), covered with dense setae; head hypognathous, protruding from pronotum partly; antenna filiform (ca. 2–5 mm, incompletely preserved); compound eye large, ocelli absent; thorax robust, long setae concentrated on pronotum. Forewing ca. 12–23 mm long, 5–8 mm wide, membranous area with many fuscous spots; humeral plate distinct; dense setae along the veins, especially on the wing margin; trichosors and nygmata undetectable; costal space dilated basally and narrowed distally; humeral veinlet recurrent, with several simple branches; costal cross-veins simple, moderately curved distally in the apical half of the costal space; Sc and R1 separate distally, entering the margin before the wing apex; one or two sc-r1 crossveins; R1 with four to eleven pectinate branches distally; the origin of Rs distant from the wing base, with seven to thirteen branches regularly arranged; relatively few crossveins present in radial area; MA simple, dichotomously branched terminally; MP first fork distant from wing base. Hind wing ca. 11–18 mm long, 4–8 mm wide, partly preserved, venation similar to forewing except for the following characters: costal space narrow, only slightly expand in proximal portion.
Lasiosmylus shows a superficial similarity with osmylids, sharing plesiomorphic features such as the fork of MP in forewing usually between the separation of MA and first Rs branch, sometimes opposite the separation of MA; wings not falcate, with few crossveins (
Herein, nine new-collected specimens are examined in this study. All these specimens are placed in Lasiosmylus based on the following characters: numerous dispersed spots on the forewing, simple costal crossveins, two subcostal crossveins, Rs less than ten branches (about six to eight branches), MP distant from the wing base and beyond MA fork, MP1 and MP2 simple, one mp1-mp2 crossvein, CuA dichotomously branched distally (in particular, obs. CNU-NEU-LB2015001P/C and CNU-NEU-LB2015002, see Figs
New materials of Lasiosmylus newi: CNU-NEU-LB2015001P/C, CNU-NEU-LB2015002. A composite photographs of habitus of part and counterpart (CNU-NEU-LB2015001P/C) hp, humeral plate (CNU-NEU-LB2015001C) B line drawing (CNU-NEU-LB2015001C) C habitus photograph, hp, humeral plate (CNU-NEU-LB2015002) D line drawing (CNU-NEU-LB2015002). Scale bars: 5 mm (A–D).
In addition, the distally separated Sc and R1 were regarded as a synapomorphic character of Ithonidae (
During the examination of the new materials, it is clear that all specimens assigned to Lasiosmylus (Figs
It is concluded here that the genus Lasiosmylus most commonly has the separated Sc and R1 that is consistent with other moth lacewings. The exception of Sc and R1 in the holotype of L. newi possibly represents a particularly individual variation, inaccuracy in line drawing or obscurity in the specimen. Based on this we consider Lasiosmylus is unquestionably assigned to the ithonid genus-group by the following combination of characters: robust and hairy body, retracted head under pronotum, costal space dilated basally and narrowed disproportionately distally, separated Sc and R1 reaching the anterior margin straightly before the wing apex, MP first fork distant from the wing base and beyond the divergence of MA.
Holotype, CNU-NEU-LB2015003, a partly preserved specimen. Body barely preserved, but four overlapping, sub-complete wings, partially folded, with visible features.
Humeral veinlet recurrent, with a few branches; numerous markings present on the forewing; a distinct oblique stripe parallel to the outer margin; costal crossveins simple; one basal subcostal crossvein; Sc and R1 separate distally, Sc terminating in costal margin 2/3 length of wing; R1 with numerous anteriorly directed branches; Rs with more than ten branches; MP fork level with origin of MA; CuA pectinately branched, CuP with three distal branches.
Body: ca. 16.3 mm long; head hypognathous, retracted into pronotum partly; antenna filiform (ca. 4.0 mm) and incompletely preserved; compound eye large, ocelli absent; pronotum quadrate, numerous long setae concentrated laterally; mesonotum and metanotum stout; abdomen and legs indiscernible. Fore wing: ca. 22.7 mm long, 7.9 mm wide; slender and membranous with numerous fuscous spots; humeral plate discernible (Fig.
The species name is from the Latin ‘longus’, referring to the slender wing of this moth lacewing.
Huangbanjigou Village, Beipiao City, Liaoning Province, China.
Yixian Formation, Barremian-early Aptian (129.7–122.1 Ma), Early Cretaceous.
Lasiosmylus longus sp. n. can be distinguished from L. newi by the distinct oblique stripe close to the outer margin, multiple Rs branches, and pectinate CuA branches.
We thank for Dr. Chungkun Shih (College of Life Sciences, Capital Normal University) for improving the manuscript. This work was supported by National Science Foundation of China (grants 31230065, 31272352, 31301905, 31672323, 41372013 and 41272006), Research Fund for the Doctoral Program of Higher Education of China (grant 20131108120005), Beijing Natural Science Foundation (grant 5132008), and Program for Changjiang Scholars and Innovative Research Team in University (IRT13081).