comment on this calibration


 node name
Aparaglossata     Look for this name in NCBI   Wikipedia   Animal Diversity Web
  recommended citations
Wolfe et al. 2016
  node minimum age
313.7 Ma
W. maryvonneae was collected from black shales in the “Terril no. 5” horizon at the “Faisceau de Modeste”, “Veine Maroc” locality in Bruayla-Bussière, Pas-de-Calais, France (Nel et al., 2007). The locality is dated as early Langsettian (Nel et al., 2007), equivalent to theWestphalian A stage (Pointon et al., 2012). There is a SHRIMP U-Pb date within the middle Langsettian estimated at 317.63 Ma ± 0.12 Myr, however, the stratigraphy of Bruay-la-Bussière is not precise enough to determine when in the Westphalian A the fossil occurred (Nel et al., 2007; Pointon et al., 2012). Therefore,we use a date inclusive of the upper boundary of theWestphalian A, which is the upper boundary ofWestphalian B. U-Pb dating of zircons constrains the upper boundary of theWestphalian B to 313.78 Ma ± 0.08 Myr (Pointon et al., 2012), so a minimum age for W. maryvonneae is 313.70 Ma.
  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 
MNHNFr LP-R.5518
Westphalomerope maryvonneae, Nel et al. 2007
Location relative to the calibrated node: Crown

[show fossil details]
     Locality: “Faisceau de Modeste”, “Veine Maroc” locality in Bruayla- Bussière, Pas-de-Calais
     Stratum: “Terril no. 5” horizon
     Geological age: Carboniferous, Paleozoic

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  phylogenetic justification
W. maryvonneae has not been included in a phylogenetic analysis, nor have any other members of its family, Protomeropidae. Mostly Permian members of Protomeropidae have been proposed to have affinities with a variety of holometabolan clades, including the total groups of Trichoptera, Mecoptera, and more generally Amphiesmenoptera or Antliophora (Grimaldi and Engel, 2005; Kukalová-Peck and Willmann, 1990; Morse, 1997; Nel et al., 2007, 2013; Sukatsheva et al., 2007). Crown amphiesmenopteran (and thus trichopteran) affinity may be unlikely, as Protomeropidae lack a key synapomorphy, a true ‘double-Y loop’ arrangement of the anal veins on the forewing (Labandeira, 2011;Minet et al., 2010). However, Permian Protomeropidae possess Carpenter's organs in the male, a probable apomorphy for total group Mecoptera (Minet et al., 2010). Protomeropidae (with a younger date) was subsequently used to calibrate the basal split of Mecopterida for divergence time estimation (Rehmet al., 2011). Pending phylogenetic analysis ofwing morphology,it is difficult to assign a specific placement for Protomeropidae, however, even with a conservative view all these possibilities are within crown Aparaglossata, and therefore crown Holometabola.
  phylogenetic reference(s)
The linked fossil has no phylogentic references.
 tree image (click image for full size) 
tree image
Figure 23 from Wolfe et al. (2016).