comment on this calibration


 node name
Thysanoptera     Look for this name in NCBI   Wikipedia   Animal Diversity Web
  recommended citations
Wolfe et al. 2016
  node minimum age
71.9 Ma
F. crassipes was found in Layer 31 on the left bank of the VitimRiver, 3 km downstream from the mouth of the Baissa River, Buryatia, Transbaikalian Russia (Shmakov, 2009). The fossiliferous lacustrine deposits are part of the Zaza Formation, Baissa locality. The Zaza Formation was once assigned to the Valanginian, based on correlation of fossil insect species, however palynological data from the appearance of Asteropollis spores suggests a younger date (O'Reilly et al., 2015; Zherikhin et al., 1998). A. asteroides, one of the earliest angiosperms, has a worldwide distribution during the Early and mid Cretaceous (Friis et al., 2005), and has been biostratigraphically assigned to the Barremian-Aptian (Friis et al., 1999; Zherikhin et al., 1998). This range has since been completely revised to Albian-Campanian, on the basis of pollen morphology (Doyle and Endress, 2014) and younger appearances of Asteropollis (Dettmann and Thomson, 1987; Eklund et al., 2004; Martínez et al., 2013). A minimum age can thus be estimated by the upper boundary of the Campanian, 72.1 Ma ± 0.2 Myr, or 71.9 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 
PIN 3064/8547
Fusithrips crassipes, Shmakov, 2009
Location relative to the calibrated node: Crown

[show fossil details]
     Locality: Baissa, Buryatia, Transbaikalian Russia
     Stratum: Zaza Formation
     Geological age: Cretaceous, Mesozoic

  phylogenetic justification
F. crassipes has not been included in a phylogenetic analysis, however, Shmakov (2009) describes characters placing it in the crown of Thysanoptera. In particular, Rs1 and M2 as crossveins rather than oblique veins suggest membership in the family Aeolothripidae (Shmakov, 2009). Whether crown or stem Aeolothripidae, the family is a part of Terebrantia, indicating crown group membership in Thysanoptera.
  phylogenetic reference(s)
Shmakov, A.S., 2009. The oldest members of the families Aeolothripidae and Thripidae (Insecta: Thysanoptera) from the Lower Cretaceous of Transbaikalia. Paleontologcal Journal 43, 428–432.
 tree image (click image for full size) 
tree image
Figure 21 from Wolfe et al. (2016)