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 node name
Palaeoptera     Look for this name in NCBI   Wikipedia   Animal Diversity Web
  recommended citations
Wolfe et al. 2016
  node minimum age
319.9 Ma
The insect beds where this species was located are near Xiaheyan Village in the Qilianshan Mountains, Zhongwei County, Ningxia Huizu Autonomous Region, northwest China (Zhang et al., 2013). The insect fossil deposits are within the uppermost unit of the upper Tupo Formation (synonyms Hongtuwa or Zhongwei Formation). The presence of the ammonoids Reticuloceras reticulatum, Gastrioceras listeri and Gastrioceras montgomeryense and conodonts Declingnathodus noduliferous and Neognathodus symmetricus indicate a Namurian B/Cage (Xie et al., 2004; Yang, 1987; Yang et al., 1988; Zhang et al., 2013).The (late) Namurian-(early) Westphalian boundary is defined by the earliest occurrence of the goniatite G. subcrenatum (Waters and Davies, 2006), but lacks a precise isotopic date. Pointon et al. (2012) estimated an age of c. 319.9Ma for the base of the Westphalian (top of the Namurian, only slightly younger than the Marsdenian) based on Milankovitch cycles of sedimentation, giving a minimum age for Xiaheyan fossils.
  node maximum age
521 Ma
A soft maximum age is obtained from the oldest mandibulate, Y. dianensis, which was recovered from the Yu'anshan Formation at Xiaotan section, Yongshan, Yunnan Province, attributed to the Eoredlichia–Wutingaspis Biozone (Zhang et al., 2007). Chinese Cambrian stratigraphy has been revised substantially and the Eoredlichia –Wutingaspis Biozone is no longer recognized (Peng, 2003, 2009). However, Eoredlichia is known to co-occur with Hupeidiscus, which is diagnostic of the Hupeidiscus-Sinodiscus Biozone, which is formally recognized as the second biozone of the Nangaoan Stage of the Qiandongian Series of the Cambrian of China (Peng and Babcock,2008). The Nangaoan is the proposed third stage of the Cambrian System for the International Geologic Timescale (Peng et al., 2012a).Thus, a soft maximum constraint can be established on the age of the lower boundary of the Nangaoan, which has been dated to 521 Ma (Peng et al., 2012a; Peng and Babcock, 2008).
 primary fossil used to date this node 
CNU NX2006003
Location relative to the calibrated node: Crown

[show fossil details]
     Locality: Xiaheyan Village
     Stratum: Tupo Formation
     Geological age: Carboniferous, Paleozoic

  phylogenetic justification
This species was originally described as Sinomeganeura huangheensis within the family Meganeuridae, part of Protodonata (Ren et al., 2008). Meganeurids include the “giant” dragonflies (with wings up to710 mm), though O. huangheensis is much smaller at 70 mm (Renet al., 2008). Despite the size difference, wing venation characters are consistent with classification in Protodonata, including the fusion of stems of CuP and CuA to a single oblique vein, distinctly stronger than the crossveins (Ren et al., 2008). This character, previously assumed to be synapomorphic for Meganeuridae, is more widespread within Protodonata (Li et al., 2013a). The group “Protodonata” itself is a paraphyletic stem group to crown Odonata, together within the total group Odonatoptera, defined by the simple MP vein (Sroka et al.,2015). Regardless of the precise relationship of Protodonata to crown Odonata, its members are definitively within crown Palaeoptera.
  phylogenetic reference(s)
Sroka P., Staniczek A.H., Bechly G., 2015. Revision of the giant pterygote insect Bojophlebia prokopi Kukalová-Peck, 1985 (Hydropalaeoptera: Bojophlebiidae) from the Carboniferous of the Czech Republic, with the first cladistic analysis of fossil palaeopterous insects. J. Syst. Palaeontol. 13, 963–982.
Li, Y., Béthoux, O., Pang, H., and Ren, D. 2013. Early Pennsylvanian Odonatoptera from the Xiaheyan locality (Ningxia, China): new material, taxa, and perspectives. Foss. Rec. 16, 117–139.
Ren, D., Nel, A., and Prokop, J., 2008. New early griffenfly, Sinomeganeura huangheensis from the Late Carboniferous of northern China (Meganisoptera: Meganeuridae). Insect Syst. Evol. 39, 223–229.
 tree image (click image for full size) 
tree image
Figure 17 from Wolfe et al. (2016).