comment on this calibration


 node name
Pan-Colubroidea     Look for this name in NCBI   Wikipedia   Animal Diversity Web
  recommended citations Head et al. 2016
  node minimum age
50.5 Ma
Procerophis was recovered from a diverse snake fauna in the Cambay Formation, Gujarat, India. The Cambay Formation is minimally dated based on the occurrence of the planktonic foraminifera taxon Nummulities burdigalensis burdigalensis, which corresponds to Shallow Benthic Zone 10 (lower Cuisian, Serra-Kiel et al., 1998). SBZ 10 corresponds to planktonic foraminiferal zone P6b, which is middle Ypresian, approximately 53-50.5 Ma (Vandenberghe et al., 2012).
  node maximum age
72.1 Ma
Maximum age is for the early Maastrichtian based on the first occurrence of Caenophidia from the Wadi Milk Formation (Werner and Rage, 1999).
 primary fossil used to date this node 
VAS 1014
Procerophis sahnii, Rage et al., 2008
Location relative to the calibrated node: Stem

[show fossil details]
     Locality: Vastan Lignite Mine, Gujarat
     Stratum: Cambay Formation
     Geological age: Cretaceous, Mesozoic

More information in Fossilworks   PaleoBioDB

  phylogenetic justification
Procerophis is assigned to Colubroidea on the basis of: elongate, narrow centrum and neural arch, paracotylar foramina, and an anteroposteriorly elongate neural spine that possesses a uniform width along its length.
  phylogenetic reference(s)
Rage, J.-C., Folie, A., Rana, R S., Singh, H., Rose, K.D. and Smith, T. 2008. A diverse snake fauna from the early Eocene of Vastan Lignite Mine, Gujarat, India. Acta Palaeontologica Polonica, 53:391-403.
 tree image (click image for full size) 
tree image
Figure 1 from Head et al. (2016).