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Megaloptera
Lineage (NCBI):
root
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» Megaloptera
| node name Megaloptera Look for this name in NCBI Wikipedia Animal Diversity Web | ||
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recommended citations Wolfe et al. 2016 |
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node minimum age 158.1 Ma This fossil was found in deposits of the Daohugou Beds, Ningcheng County, Inner Mongolia, China (Huang et al., 2008a). There has been controversy about the accuracy and precise age and stratigraphic position of the Daohugou Beds (Gao and Ren, 2006; Wang et al., 2005;Zhang, 2015). The beds consist of 100–150 m thick succession of grey white or locally reddish, thinly bedded claystones, shales, siltstones and sandy mudstones with intercalated ash-fall tuffs and ignimbrites. Ages have been proposed from Aalenian (Middle Jurassic) to Early Cretaceous (Liu et al., 2014;Wang et al., 2000),with several studies converging on Callovian-Oxfordian (Late Jurassic; Zhang, 2015). Radiometric dating of the ignimbrite swith 40Ar/39Ar and SHRIMP U-Pb variously yields dates between 165Ma±2.5Myr and 158.7Ma±0.6Myr (Chang et al., 2009b; Gao and Ren, 2006; He et al., 2004; Peng et al., 2012b). The fossiliferous shales overlay the volcanic deposits (Gao and Ren, 2006),and are thus younger. The isotopic dates nonetheless provide a reasonable refutation of Cretaceous age estimates. Furthermore, the Daohugou Beds may be correlated to sediments from Oxfordian localities in China and Kazakhstan (Zhang, 2015). The most conservative (i.e. youngest) ofthe direct radiometric dates is 158.1 Ma (within the Oxfordian), giving a minimum age. | ||
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node maximum age 411 Ma A soft maximum age is estimated from R. praecursor, the oldest hexapod, from the Early Devonian (Pragian) Rhynie Chert of Aberdeenshire, Scotland. Spore assemblages of the Windyfield and stratigraphically underlying Rhynie Chert are dated to the early but not earliest Pragian to early (earliest?) Emsian (polygonalis-emsiensis Spore Assemblage Biozone) (Parry et al., 2011). Radiometric dating of the underlying Milton of Noth Andesite at ca. 411 Ma (Parry et al., 2011, 2013) has been subject to a dispute over its temporal relationship to hot spring activity associated with the cherts (Mark et al., 2011, 2013) and predates the biostratigraphic dating of the Rhynie Chert relative to the global dating of the base of the Pragian Stage. Therefore, a soft maximum constraint may be defined at 411 Ma for the Rhynie Chert. | ||
| primary fossil used to date this node | ||
CNU MEG-NN2011004 P | ||
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phylogenetic justification
E. striolatus was included in a phylogenetic analysis of morphology, encompassing characters from wing venation, adult genitalia, and larval morphology where possible (Liu et al., 2012). E. striolatus was found within the crown Corydalidae, at the base of the ‘Protochauliodes clade’ (comprising extant species). This position is therefore within crown Megaloptera. The bifurcated anterior branch of the Rs vein is a relevant synapomorphy (Liu et al., 2012). |
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phylogenetic reference(s)
Liu, X.,Wang, Y., Shih, C., Ren, D., Yang, D. 2012. Early evolution and historical biogeography of fishflies (Megaloptera: Chauliodinae): implications from a phylogeny combining fossil and extant taxa. PLoS One 7, e40345.
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| tree image (click image for full size) | ||
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Figure 23 from Wolfe et al. (2016).
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