comment on this calibration


 node name
Anisoptera     Look for this name in NCBI   Wikipedia   Animal Diversity Web
  recommended citations Kohli et al., 2016
  node minimum age
168 Ma
The Daohugou-Biota, resting on the Jiulongshan Formation, has been dated with SHRIMP U-Pb zircon age of 168-152 Ma, giving a minimum age for Jiulongshan Formation of 168 Ma (Liu et al., 2006). Because the Daohugou Formation overlies the Jiulonshan formation, he age range of the former provides a minimum age as 168 Ma for the calibrating fossil.
  node maximum age
None specified
 primary fossil used to date this node 

 tree image (click image for full size) 
tree image
Figure 3 from Kohli et al. (2016).