comment on this calibration


 node name
Upupiformes     Look for this name in NCBI   Wikipedia   Animal Diversity Web
  recommended citations Ksepka and Clarke, 2015
  node minimum age
46.6 Ma
SMF-ME 1883a+b was collected from the Messel Pit. A maximum age for the fossiliferous deposits of the Messel Formation is provided by a 47.8 ± 0.2 Ma 40Ar/39Ar age obtained from the basalt chimney below Lake Messel (Mertz et al., 2004). This date provides a maximum age for Lake Messel itself, but a minimum age for the fossil must take into account time elapsed between the cooling of the basalt and the deposition of the fossiliferous layers which occur higher in the section. Lacustrine sediments are estimated to have filled in the maar lake that formed above this basalt chimney over a span of approximately 1 Ma (Mertz et al., 2004). Accounting for sedimentation rate, the layers yielding avian fossils (including SMF-ME 1883a+b) are most likely ~47 Ma in age (Mertz et al., 2004; Franzen, 2005). When both the error range associated with the dating of the basalt (±0.2Ma) and the estimate of time spanned between this date and deposition of the fossil (1Ma) are incorporated, the hard minimum age for the fossil is 46.6Ma.
  node maximum age
0 Ma
None specified
 primary fossil used to date this node 
SMF ME-1883a+b
Messelirrisor halcyrostris , Mayr, 1998
Location relative to the calibrated node: Stem

[show fossil details]
     Locality: Messel
     Stratum: Messel Formation
     Geological age: Lutetian, Eocene, Paleogene, Cenozoic

  phylogenetic justification
Phylogenetic analysis of morphological data (Mayr, 2006) places Messelirrisor halcyrostris as a stem representative of Upupiformes.
  phylogenetic reference(s)
Mayr, G. 2006. New specimens of the Eocene Messelirrisoridae (Aves: Bucerotes), with comments on the preservation of uropygial gland waxes in fossil birds from Messel and the phylogenetic affinities of Bucerotes. Paläontologische Zeitschrift, 80:390-405.
 tree image (click image for full size) 
tree image
Figure 13 of Ksepka and Clarke (2014): Phylogenetic tree showing position of Messelirrisor halcyrostris, illustrating the divergence calibrated by SMF-ME 1883a+b.