comment on this calibration

Orthoptera

 node name
Orthoptera     Look for this name in NCBI   Wikipedia   Animal Diversity Web
 
  recommended citations
Wolfe et al. 2016
 
  node minimum age
271.8 Ma
R. rubra was found at the fossiliferous site F21 D, at “Le Moural D”, in the basal Mérifrons Member of the Salagou Formation (Saxonian Group), near village Octon, Lodève Basin, Hérault, France (Béthoux et al., 2002; Nel et al., 1999; Schneider et al., 2006). U-Pb dates have been recently measured from zircons lying in tuff beds near the lower two-thirds of the Salagou Formation (Octon Member), in the Artinskian (Michel et al., 2015). The Mérifrons Member, overlying the Octon, is therefore inferred to be Artinskian at its base but continuing up through the Kungurian (Michel et al., 2015). As the exact stratum of the F21 site is not indicated within the Mérifrons member (Michel et al., 2015; Schneider et al., 2006), we apply a conservative minimum estimate from the upper bound of the Kungurian (272.3 Ma ± 0.5 Myr), at 271.8Ma.
 
  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 
 
ld LAP 415 B
Raphogla rubra, Béthoux et al. 2002
Location relative to the calibrated node: Crown

[show fossil details]
     Locality: F21 D, at “LeMoural D”
     Stratum: Mérifrons Member of the Salagou Formation
     Geological age: Permian, Paleozoic


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  phylogenetic justification
Although no cladistic analysis exists combining extant and fossil Enserifa, R. rubra may be assigned to crown Enserifa based on forewing venation characters (Béthoux et al., 2002). It likely belongs to the stem group of the clade (Gryllidea + Tettigoniidea), based on the following characters: very broad area between anterior margin and Sc; RS moderately long basal of a short fusion with the anterior branchMA1a of MA; MP+CuA1with only one simple anterior branch (Béthoux et al., 2002). As both Gryllidea and Tettigoniidea are crown clades within crown Enserifa, R. rubra is within crown group Orthoptera.
 
  phylogenetic reference(s)
Béthoux, O., Nel, A., Lapeyrie, J., Gand, G., Galtier, J., 2002. Raphogla rubra gen. n., sp. n., the oldest representative of the clade of modern Ensifera (Orthoptera: Tettigoniidea, Gryllidea). Eur. J. Entomol. 99, 111–116.
 
 tree image (click image for full size) 
tree image
Figure 19 from Wolfe et al. (2015).
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