The species of the Strashilidae (strashilids) have been the most perplexing of fossil insects from the Jurassic period of Russia and China1,2. They have been widely considered to be ectoparasites of pterosaurs or feathered dinosaurs, based on the putative presence of piercing and sucking mouthparts and hind tibio-basitarsal pincers purportedly used to fix onto the host’s hairs or feathers1,2,3,4,5,6. Both the supposed host and parasite occur in the Daohugou beds from the Middle Jurassic epoch of China (approximately 165 million years ago)7,8. Here we analyse the morphology of strashilids from the Daohugou beds, and reach markedly different conclusions; namely that strashilids are highly specialized flies (Diptera) bearing large membranous wings, with substantial sexual dimorphism of the hind legs and abdominal extensions. The idea that they belong to an extinct order2 is unsupported, and the lineage can be placed within the true flies. In terms of major morphological and inferred behavioural features, strashilids resemble the recent (extant) and relict members of the aquatic fly family Nymphomyiidae. Their ontogeny are distinguished by the persistence in adult males of larval abdominal respiratory gills, representing a unique case of paedomorphism among endopterygote insects. Adult strashilids were probably aquatic or amphibious, shedding their wings after emergence and mating in the water.
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Rasnitsyn, A. P. Strashila incredibilis, a new enigmatic mecopteroid insect with possible siphonapteran affinities from the Upper Jurassic of Siberia. Psyche (Stuttg.) 99, 323–334 (1992)
Vršanský, P., Ren, D. & Shih, C. Nakridletia ord. n. – enigmatic insect parasites support sociality and endothermy of pterosaurs. AMBA Projekty 8, 1–16 (2010)
Labandeira, C. in The Fossil Record of Predation (eds Kowalevski, M. & Kelley, P. H. ) 211–249 Paleontological Society Special Papers, Vol. 8 (Paleontological Society, Yale Printing Service, 2002)
Grimaldi, D. A. & Engel, M. S. Evolution of the Insects (Cambridge Univ. Press, 2005)
Gao, T.-P., Shih, C., Xu, X., Wang, S. & Ren, D. Mid-Mesozoic flea-like ectoparasites of feathered or haired vertebrates. Curr. Biol. 22, 732–735 (2012)
Poinar, G. O., Jr Palaeontology: the 165-million-year itch. Curr. Biol. 22, R278–R280 (2012)
Wang, X., Zhou, Z., Zhang, F. & Xu, X. A nearly completely articulated rhamphorhynchoid pterosaur with exceptionally well-preserved wing membranes and ‘hairs’ from Inner Mongolia, northeast China. Chin. Sci. Bull. 47, 226–230 (2002)
Zhang, F., Zhou, Z., Xu, X., Wang, X. & Sullivan, C. A bizarre Jurassic maniraptoran from China with elongate ribbon-like feathers. Nature 455, 1105–1108 (2008)
Huang, D. Diversity of Jurassic insects—exemplified by Daohugou fauna. Front. Earth Sci. 17 (special issue). 149–150 (2010)
Huang, D., Engel, M. S., Cai, C., Wu, H. & Nel, A. Diverse transitional giant fleas from the Mesozoic era of China. Nature 483, 201–204 (2012)
Wood, D. M. in Proc. 2nd Int. Congress Dipterol (eds Weismann, L., Országh, I. & Pont, A. C. ) 255–284 (SPB Academic Publishing, 1991)
Crampton, G. C. The genitalia of male Diptera and Mecoptera compared with those of related insects, from the standpoint of phylogeny. Trans. Am. Entomol. Soc. 48, 207–225 (1922)
Willmann, R. Das exoskelett der mannlichen genitalien der Mecoptera (Insecta). 1. Morphologie. Zeit. Zool. Syst. Evolutionsf. 19, 96–150 (1981)
Courtney, G. W. Biosystematics of the Nymphomyiidae (Insecta: Diptera): life history, morphology, and phylogenetic relationships. Smith. Cont. Zool. No. 550 (Smithsonian Institution, 1994)
Kevan, D. K., McE & Cutten-Ali-Khan, F. E. A. Canadian Nymphomyiidae (Diptera). Can. J. Zool. 53, 853–866 (1975)
Kevan, D. K., McE & Cutten, F. E. A. in Manual of Nearctic Diptera Vol. 1 (eds McAlpine, J. F. et al. ) 203–207 (Research Branch, Agricultural Canada Monograph, 1981)
Furth, D. G. & Suzuki, K. The metatibial extensor and flexor tendons in Coleoptera. Syst. Entomol. 15, 443–448 (1990)
Daugeron, C., Plant, A., Winkler, I., Stark, A. & Baylac, M. Extreme male leg polymorphic asymmetry in a new empidine dance fly (Diptera: Empididae). Biol. Lett. 7, 11–14 (2011)
Richmond, E. A. Studies on the biology of the aquatic Hydrophilidae. Bull. Am. Mus. Nat. Hist. 42, 1–94 (1920)
Barclay, A., Portman, R. W. & Hill, P. S. M. Tracheal gills of the dobsonfly larvae, or hellgrammite Corydalus cornutus L. (Megaloptera: Corydalidae). J. Kans. Entomol. Soc. 78, 181–185 (2005)
Speidel, W. Studies on the phylogeny of the Acentropinae (Lepidoptera, Crambidae). Mém. Soc. R. Belge Entomol. 38, 25–30 (1998)
Ide, F. P. A fly of the archaic family Nymphomyiidae (Diptera) from North America. Can. Entomologist 97, 496–507 (1965)
Wagner, R., Hoffeins, C. & Hoffeins, H. W. A fossil nymphomyiid (Diptera) from the Baltic and Bitterfeld amber. Syst. Entomol. 25, 115–120 (2000)
Štys, P. & Soldan, T. Retention of tracheal gills in adult Ephemeroptera and other insects. Acta Univ. Carol. (Biol.) 1978, 409–435 (1980)
Marden, J. H. & Thomas, M. A. Rowing locomotion by a stonefly that possesses the ancestral pterygote condition of co-occurring wings and abdominal gills. Biol. J. Linn. Soc. 79, 341–349 (2003)
Cao, C.-Q. et al. Respiratory system and respiratory behaviors of the larva of Neoneuromus ignobilis. Chin. J. Appl. Entomol. 48, 392–396 (2011)
Cutten, F. E. A. & Kevan, D. K. McE. The Nymphomyiidae (Diptera), with special reference to Palaeodipteron walkeri Ide and its larva in Quebec, and a description of a new genus and species from India. Can. J. Zool. 48, 1–24 (1970)
We are grateful to C. C. Labandeira for suggestions; A. P. Rasnitsyn for early discussions; and J. Sun for reconstructions. Financial support was provided by the National Basic Research Program of China (2012CB821903), the National Natural Science Foundation of China (91114201 and J1210006), the Outstanding Youth Foundation of Jiangsu Province (BK2012049), the Chinese Academy of Sciences (KZCX2-YW-QN104), and the US National Science Foundation (DEB-0542909).
The authors declare no competing financial interests.
The LSID urn:lsid:zoobank.org:act:85DDCF37-C0D1-45C0-80B3-463E9D19ECE1 has been deposited in ZooBank.
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Huang, D., Nel, A., Cai, C. et al. Amphibious flies and paedomorphism in the Jurassic period. Nature 495, 94–97 (2013). https://doi.org/10.1038/nature11898
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