comment on this calibration


 node name
Mecoptera     Look for this name in NCBI   Wikipedia   Animal Diversity Web
  recommended citations
Wolfe et al. 2016
  node minimum age
271.8 Ma
This fossil occurs in the Carlton Limestone Member of the Wellington Formation in the Sumner Group of Elmo, Dickinson County, central Kansas (Prokop et al., 2015; Zambito et al., 2012). The insect bearing locality is correlated with the Leonardian regional Stage (Sawin et al., 2008; Zambito et al., 2012) on the basis of conchostracan biostratigraphy (Tasch, 1962). The Leonardian spans the Artinskian and the younger Kungurian Stage (Henderson et al., 2012). The upper boundary of the Kungurian is 272.3 Ma±0.5 Myr, thus providing a conservative minimum age estimate of 271.8 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 
YPM 005058
Permopanorpa inaequalis, Tillyard, 1926
Location relative to the calibrated node: Crown

[show fossil details]
     Locality: Elmo, Dickinson County
     Stratum: Carlton Limestone Member of the Wellington Formati
     Geological age: Permian, Paleozoic

More information in Fossilworks   PaleoBioDB

  phylogenetic justification
P. inaequalis is the oldest member of the family Permopanorpidae, which was coded (at the family level) in the morphological matrix of Ren et al. (2009). In that tree, it was part of the total group of Antliophora (although the figure label indicated it was inside crown Antliophora, the topology clearly indicates it was on the stem lineage; Ren et al., 2009). As a stem group member of Antliophora, P. inaequalis is thus crown group Mecopterida.
  phylogenetic reference(s)
Ren, D., Labandeira, C.C., Santiago-Blay, J.A., Rasnitsyn, A.P., Shih, C., Bashkuev, A., Logan, M.A.V., Hotton, C.L., Dilcher, D.L., 2009. A probable pollination mode before angiosperms: Eurasian, long-proboscid scorpionflies. Science 326, 840–846.
 tree image (click image for full size) 
tree image
Figure 24 from Wolfe et al. (2016).