Zootaxa,The oldest known record of Taeniopterygidae in the Middle ...

Zootaxa 1521: 1–8 (2007) www.mapress.com / zootaxa/

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ZOOTAXA

The oldest known record of Taeniopterygidae in the Middle Jurassic of Daohugou, Inner Mongolia, China (Insecta: Plecoptera) YUSHUANG LIU1, DONG REN1,3 NINA D. SINITSHENKOVA2 & CHUNG KUN SHIH1 1

College of Life Sciences, Capital Normal University, 105 Xisanhuanbeilu, Haidian District; Beijing 100037; China Palaeontological Institute of the Russian Academy of Sciences, Profsoyuznaya 123, Moscow, Russia 3 Corresponding author. E–mail: [email protected] 2

Abstract Two new genera and three new species of family Taeniopterygidae, Jurataenionema inornatus Liu and Ren, gen. et sp. nov., Jurataenionema stigmaeus Liu and Ren, gen. et sp. nov. and Protaenionema fuscalatus Liu and Shih, gen. et sp. nov. are described from Daohugou village (Middle Jurassic), Inner Mongolia, China. These are the oldest records of Taeniopterygidae. The venations of these two genera were very simple, providing evidence that the costal crossveins and the occasional apical crossveins are derived characters. We suggest the same is true of the extra branches of Rs and CuA in family Taeniopterygidae. Extra branches and crossveins added through geologic time might have improved aerodynamics of the wings. Key words: Plecoptera, Taeniopterygidae, Daohugou, Inner Mongolia, Middle Jurassic

Introduction The family Taeniopterygidae contains about 80 extant species that are distributed mainly in Europe and North America and a few are in Central Asia (Ricker & Ross 1975, Zhiltzova 1972, Zwick 1973). Two species in two genera are recorded in China from the Himalayas of Tibet and Baima Jokul of Yunnan Province (Du 1999). Taeniopterygid fossils are very rare, with only 6 species in 4 genera having been reported (Liu & Ren 2006). Among them, 3 species were found in Cenozoic strata and belong to two extant genera (Sinitshenkova 1997); the remaining species were collected from Early Cretaceous rocks in Mongolia and Siberia and belong to extinct genera (Sinitshenkova 1986, 1987). Recently, we collected numerous Plecoptera fossils from Daohugou Village, Inner Mongolia, China (Liu et al. 2006). Nine specimens possess typical characters of Taeniopterygidae, which include venation, tarsus and cerci. They are the oldest specimens of this family, living in the Middle Jurassic about 164 Ma. The lacustrine deposits at Daohugou Village contained a diverse insect fauna composed of at least fourteen orders and more than 50 genera and 200 species (Zhang 2002, Yao et al. 2006, Tan et al. 2006, Zhang et al. 2006) and many other animal fossils: conchostracans (Zhang & Shen 1987, Shen et al. 2003), salamanders (Wang 2004, Gao & Shubin 2003), pterosaurs (Wang et al. 2002, Czerkas & Ji 2002), feathered maniraptora (Zhang et al. 2002), and mammalia (Ji et al. 2006). The age of Daohugou beds is still debated, ranging from the early Middle Jurassic to Early Cretaceous by various authors, even the same authors, as their research progressed, provided different opinions at different times (Zhang 2005). Recently, Ar–Ar and SHRIMP U–Pb dating shows that the age of intermediate–acidic volcanic rocks overlying the Daohugou fossil–bearing beds (N41° 18.979', E119° 14.318') is about 164–165

Accepted by E. Dewalt: 12 May 2007; published: 5 Jul. 2007

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Ma, and the age of Daohugou beds is older than or equal to that of Chen et al. (2004). Liu et al (2006) estimated the age of the Daohugou section (N41° 23.10'E119 09.61) and drew a similar conclusion, that the average age of the Daohugou beds was 162+2 Ma. This conclusion, supported by paleontological evidence from conchostracans and insects, is the most definitive evidence for the Middle Jurassic (Aalenian-Bathonian) age of the Daohugou beds (Gao & Ren 2006).

Material and methods All the fossils described herein were collected from Daohugou Village, Chifeng City, Inner Mongolia, China; Middle Jurassic. They were examined using a LEICA MZ12.5 dissecting microscope and illustrated with the aid of a drawing tube. Line drawings were processed using CorelDraw 12 graphic software. Type specimens described here are housed in the Key Laboratory of Insect Evolutionary and Environment Change, College of Life Sciences, Capital Normal University, Beijing, China.

Systematic palaeontology Suborder Arctoperlaria Zwick, 1969 Family Taeniopterygidae Klapálek, 1905 Genus Jurataenionema Liu and Ren, gen. nov. Type species. Jurataenionema inornatus Liu and Ren, sp. nov.

Etymology. The generic name is taken from the combination of Jura and Taenionema (a genus of Taeniopterygidae) Species included. The type species J. inornatus Liu and Ren, sp. nov. and J. stigmaeus Liu and Ren, sp. nov. Diagnosis. Wings are macropterous, translucent. No additional veinlets on the costal area, c–r present or very faint, sometimes grey pterostigma presents in the terminal space of forewings; Rs with three branches, M and CuA with two long branches, and fork at level of midlength of Rs stem; 5–8 crossveins in the median and cubital areas. Ninth sternite produced, with a median tongue–like erect and then bent forward extension tapering to around or cuspidal tip, tenth tergite transversely wide, sclerotized. Cerci short, eight to ten segments. Remarks. The new genus Jurataenionema differs from the extant genera by the longer cerci and long branches of CuA; differs from the extinct Gurvanopteryx by Rs with three branches and the longer first segment of hind tarsus; differs from the extinct Positopteryx by c–r present, Rs with three branches.

Jurataenionema inornatus Liu and Ren, sp. nov. Figs. 1–2 Etymology. From Latin inornatus, means the wing luculent, without any stigma in the terminal space of forewings. Materials. Holotype, female. CNU, NMDHG61, a well–preserved body with part of wings, and a paratype (imago) from the same locality: CNU, NMDHG145. Description. Length of body 11–13 mm, to tip of wings 16–17 mm. Head large, almost triangle, the basal part is 1.5X as wide as the distal; antenna long, longer than body. Cervix preserved clearly, narrow. Prothorax transverse, two–thirds of mesothorax length.

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Forewings: 14–15 mm length. Costal area without additional veinlets, Sc terminates R nearly to two– thirds of the total wing length, c–r far from the Sc tip. Rs departs from R at one–sixth of the base, and forks distinctly after r–rs, its anterior branch forks again at the midlength. r–rs short, almost vertical to Rs, M bifurcates slightly basal of the midlength of wing, and its branches are nearly twice as long as Rs branches, rs–m straight, connects with Rs before r–rs and terminates at the one fifth of MA. Crossvein m–cua S–shaped, connecting M at the same level of M forks, and terminated the stem of CuA. Vein CuA forks basal to M forks, its anterior branch long, almost twice as long as the posterior branch, 5–8 crossveins at the median and cubital areas. Abdomen with 10 visible segments, slightly longer than head and thorax together. Ninth sternite produced, the median tongue upturned, narrowly round, tenth tergite transversely wide, sclerotized. Cerci short, its segments faint, about 8–10 segments. Legs long, coxa and trochanter wide, femur robust, nearly twice as wide as tibia, tibia slender, about 1.3X as long as femur, tarsus long, half a length of tibia, three segments are of almost the same length. Remarks. The new species J. inornatus resembles extant Mesyatsia thianshanica (Zhiltzova 1972) in venation, except Rs has three branches and there is no costal crossvein. In addition, no pterostigma exists, while it is present in M. thianshanica.

FIGURES 1, 2. Jurataenionema inornatus gen. et sp. nov. Holotype, CNU, NMDHG61. Scale bar represents 2 mm, ventral view.

Jurataenionema stigmaeus Liu and Ren, sp. nov. Figs. 3–5 Etymology. From Latin stigmaeus, refers to the presence of a fuscous stigma in the terminal space of forewings.

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Materials. Holotype, female. CNU, NMDHG 183, a well–preserved body with part of wings, and paratypes (Imagoes) from the same locality: CNU, NMDHG 99, and CNU, NMDHG 184–187. Description. Length of body 14 mm, to tip of wings 18 mm. Head large, triangular, the posterior part not twice as wide as the anterior; antennae long. Prothorax narrow, two–thirds of the mesothorax; mesothorax and metathorax developed, same width. Legs robust. Forewings 15 mm length. Sc connected to R at almost two–thirds total wing length; c–r far from the Sc tip, grey pterostigma present; Rs forks distinctly after the r–rs, and its anterior branch forks again close to the Rs forks. Crossvein r–rs short, almost perpendicular to Rs. M appears 2–branched, forking from the proximal 1/3 of the wing, its branches are nearly twice as long as Rs branches, rs–m straight, connects Rs before r–rs and terminates at the one fifth of MA. Crossvein m–cua S–shaped, connecting M stem or MP, and terminated the stem of CuA. CuA forks close to M forks, with long anterior branch. 4 crossveins at the median area, 7 crossveins at the cubital areas. Abdomen with 10 visible segments, almost 1.7 times as long as thorax. Ninth sternite produced as a subgenital plate, the median tongue upturned, triangular. Cerci short, eight or nine segments. Remarks. The new species J. stigmaeus differs from the type species by the defined pterostigma.

FIGURES 3, 4. Jurataenionema stigmaeus gen. et sp. nov. Holotype, CNU, NMDHG183. Scale bar represents 2 mm, dorsal view.

Genus Protaenionema Liu and Shih, gen. nov. Type species. Protaenionema fuscalatus Liu and Shih, sp. nov.

Etymology. Named from a combination of the prefix pro- and Taenionema.


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FIGURES 5. Jurataenionema stigmaeus gen. et sp. nov. Paratype, CNU, NMDHG99, ventral view. Scale bar represents 2 mm.

Species included. Only the type species P. fuscalatus Liu and Shih, sp. nov. Diagnosis. Wings of normal length, brown. Lack of additional veinlets on the costal area, crossvein c–r absent; Rs and M both with two branches. Ninth sternite produced, distinctly exceeds the tenth segment, not upturned, and the distal margin rounded, tenth tergite transversely wide, sclerotized. Cerci short, multisegmented. Remarks. In the extant genera, c–r is generally present, absent only in Brachyptera and in the glacialis and contorta group of Oemopteryx (Ricker & Ross 1975). Crossvein c–r is absent in this new genus Protaenionema. It is difficult to distinguish this new genus and extant genus Brachyptera and the glacialis and contorta group of Oemopteryx according to the preserved characters of Protaenionema. Brachyptera has developed extra branches (three to five branches) of CuA and cerci with one or two segments, but these important characters are not preserved clearly in Protaenionema; similarly, the typical features (two prongs) of epiproct of Oemopteryx cannot be observed in Protaenionema. The new extinct genus Protaenionema differs from the extinct Gurvanopteryx and Positopteryx by the opaque, slightly brown wings and by the distinctly produced ninth sternite. It differs from the new Jurataenionema by having an Rs with two branches and the fuscous wings.

Protaenionema fuscalatus Liu and Shih, sp. nov. Figs. 6–7 Etymology. The species name is taken from a combination of the Latin fuscus (meaning dark) and the Latin alatus (meaning winged).

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Materials. Holotype, sex unknown. CNU, NMDHG 55, a well–preserved body with part of wings. Description. Length of body 17 mm, to tip of wings 21 mm, color dark. Head large, subtriangular, the basal part twice as wide as the distal; antennae shorter than body. Thorax distorted and compressed laterally, structure unclear. Forewing length 16 mm, opaque, fuscous. Vein Sc unites with R at 2/3 total wing length. Crossevein c–r absent, Rs oblique at the base, 2–branched, forked distal to cord. Vein M 2–branched from middle of wing, its branches nearly twice as long as Rs branches. Crossvein rs–m straight, parallels r–rs, connecting Rs proximal to r–rs, terminating at the proximal 1/3 of MA. Crossvein m–cua straight, connecting M stem and CuA stem. Branches of CuA not discernable, only the distal part of first branch of CuA preserved. At least 5 crossveins at the median area. Abdomen with 10 visible segments, almost twice as long as thorax. Every segment is of almost same width except for the last two segments, and three to eight segments are relative longer than first two segments. The ninth sternite produced, greatly exceeding the 10th segment, its tip not upturned, broadly round; the 10th tergite short, sclerotized. Cerci short, multisegmented, its segments faint. Legs robust, coxa and trochanter wide, femur short and brawny, nearly twice as wide as tibia, tibia slender, tarsi long, half length of tibia, the first segment slightly longer than the second one which is equal to the third segment. Claw short, wide basally.

FIGURES 6, 7. Protaenionema fuscalatus gen. et sp. nov. Holotype, CNU, NMDHG55. Scale bar represents 2 mm, ventral view.

Discussion In stoneflies, as in most insects, the general evolutionary trend has been toward a reduction of venation, but an exception occurs in taeniopterygids. Taeniopteryx and Kohnoperla are primitive species in most respects,


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which possess the simplest and the most typical venation. This includes the presence of crossvein c–r, absence of costal crossveins, and Rs and CuA with two branches. Ricker & Ross (1975) thought the extra branches of Rs and CuA should be regarded as derived characters, similarly with costal crossveins and the occasional apical crossveins found in the family. The fact that the new genera Jurataenionema and Protaenionema were found supports their hypothesis that the ancient species of the family possess simple venation. Hitherto, the Jurataenionema and Protaenionema found in Middle Jurassic are the oldest fossils species in this family and possess primitive venation features. Why did taeniopterygids reacquire many extra branches or crossveins, and make the venation complicated? Ricker & Ross (1975) have proposed that it resulted from natural selection, and the action of natural selection would be associated with aerodynamic changes in flight behavior. It is very difficult to pinpoint the exact reasons with certainty from the fossils at the present time.

Acknowledgements This research was supported by grants from the National Nature Science Foundation of China (No. 30025006, 30370184, 30430100), Scientific Research Key Program (KZ200410028013), PHR Project of Beijing Municipal Commission of Education, and the program of the Presidium of the Russian Academy of Sciences The origin and evolution of the Biosphere.

References Chen, W., Ji, Q., Liu, D.Y., Zhang, Y., Song, B. & Liu, X.Y. (2004) Isotope geochronology of the fossil–bearing beds in the Daohugou, Ningcheng, Inner Mongolia. Geological Bulletin of China, 23, 1165–1169 [in Chinese, English summary]. Czerkas, S.A. & Ji, Q. (2002) A new rhamphorhynchoid with a headcrest and complex integumentary structures, In: Czerkas, S. J. (ed.), Feathered Dinosaura and the origin of flight. Blanding: The Dinosaur Museun of Blanding Journal, 1, 15–41. Du, Y.Z. (1999) Class insecta: Order Plecoptera. In: Zheng, L.Y. & Gui, H. (editors), Insect classification. Nanjing: Nanjing Normal University Publishing House. P 146–168 [in Chinese]. Gao, K.Q. & N. Shubin. (2003) Earliest known crown–group salamanders. Nature, 422, 424–428. Gao, K.Q. & Ren, D. (2006) Radiometric dating of Ignimbrite from Inner Mongolia provides no indication of a Post– Middle Jurassic Age for the Daohugou Bed. Acta Geologica Sinica, 80, 41–45. Ji, Q., Luo, Z.X., Yuan, C.X. & Alan, R.T. (2006) A swimming Mammaliaform from the Middle Jurassic and ecomorphological diversification of early Mammals. Science, 311, 1123–1127. Klapálek, F. (1905) Conspectus Plecopterorum Bohemiae. Casopis Ceskoslovenske Spolecnosti Entomologicke, 2, 27– 32. Liu, Y.Q., Liu, Y.X., Ji, S.A. & Yang, Z.Q. (2006) U–Pb Zircon age for the Daohugou Biota at Ningcheng of Inner Mongolia and comments on related issues. Chinese Science Bulletin, 51, 2634–2644 [in Chinese with English abstract]. Liu, Y.S., Ren, D., Sinitshenkova, N.D. & Shih C.K. (2006) A new Middle Jurassic Stonefly from Daohugou, Inner Mongolia, China (Insecta: Plecoptera). Annales Zoologici (Warszawa), 56(3), 549–554. Liu, Y.S. & Ren, D. (2006) Progress in the study of plecoptera fossils. Acta Zootaxonomica Sinica, 31, 683–691 [in Chinese with English abstract]. Ricker, W.E. & Ross, H.H. (1975) Synopsis of the Brachypterinae, (Insecta: Plecoptera:Taeniopterygidae). Canadian Journal of Zoology, 53, 132–153. Shen, Y.B., Chen, P.J. & Huang, D.Y. (2003) Age of the fossil conchostracans from Daohugou of Ningcheng, Inner Mongolia. Journal of Stratigraphy, 27, 311–313 [in Chinese, English summary]. Sinitshenkova, N.D. (1986) Stoneflies. Perlida (Plecoptera). In: Rasnitsyn, A.P. (ed.), Insects in the Early Cretaceous Ecosystems of the Western Mongolia. Trudy Sovmestnaya Sovetsko–Mogolskaya Paleontologicheskaya Ekspeditsiya, 28, 169–171 [in Russian]. Sinitshenkova, N.D. (1987) Historical development of the stoneflies. Trudy Paleontolgischeskogo Instituta Akademii. Nauk SSSR, Moscow, Nauka Press, 221, 144 pp [in Russian]. Sinichenkova, N.D. (1997) Palaeontology of stoneflies. In: P. Landolt & M. Sartori (eds.). Ephemeroptera & Plecoptera: Biology-Ecology-Systematics. Fribourg. P. 561–565. TAENIOPTERYGIDAE IN THE MIDDLE JURASSIC


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Tan, J.J., Ren, D. & Shih, C.K. (2006) New cupedids from the Middle Jurassic of inner Mongolia, China (Coleoptera: Archostemata). Annales Zoologica (Warszawa), 56, 1–6. Wang, Y. (2004) A new Mesozoic caudate (Liaoxitriton daohugouensis sp.nov.) from Inner Mongolia,China. Chinese Science Bulletin, 49, 858–860. Wang, X.L., Zhou, Z.H., Zhang, F.C. & Xu, X. (2002) A nearly completely articulated rhamphorhynchoid pterosaur with exceptionally well–preserved wing membranes and hair from Inner Mongolia, northeast China. Chinese Science Bulletin, 47, 226–230. Yao, Y.Z, Cai, W.Z. & Ren, D. (2006) The first discovery of fossil rhopalids (Heteroptera: Coreoidea) from Middle Jurassic of Inner Mongolia, China. Zootaxa, 1269, 57–68. Zhang, F.C., Zhou, Z.H., Xu, X. & Wang, X.L. (2002) A juvenile coelurosaurian theropod from China indicates arboreal habits. Naturwissenschaften, 89, 394–398. Zhang, J.F. (2002) Discovery of Daohugou Biota (pre–jehol biota) with a Discussion on its geological age. Journal of Stratigraphy, 26, 173–177 [in Chinese, English summary]. Zhang, J.F. (2005) The first find of chrysomelids (Insecta: Coleopetra: Chrysomeloidea) from Callovian-Oxfordian Daohugou biota of China. Geobios, 38, 865–871. Zhang, K.Y., Yang, D. & Ren, D. (2006) The first snipe fly (Diptera: Rhagionidae) from the Middle Jurassic of Inner Mongolia, China. Zootaxa, 1134, 51–57. Zhang, W.T. & Shen, Y.B. (1987) Discovery of Jurassic conchostracans with well–preserved soft parts and notes on its biological significance. Acta Palaeontologica Sinica, 26, 127–148. Zhiltzova, L.A. (1972) Taeniopterygidae, a family of stonefly (Plecoptera) new to the fauna of Central Asia. Zoologichesky zhurnal, 51, 1815–1822 [in Russion, English summary]. Zwick, P. (1969) Das phylogenetische system der Plecoptera als Ergebnis vergleichend–anatomischer Untersuchengen. Dissertation University of Kiel, 291 pp. Zwick, P. (1973) Insecta: Plecoptera, Phylogenetisches System und Katalog. Das Tierreich, Berlin, 94, 1–465 pp.


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