comment on this calibration


 node name
Coliiformes     Look for this name in NCBI   Wikipedia   Animal Diversity Web
  recommended citations Ksepka and Clarke, 2015
  node minimum age
56.22 Ma
USNM 433912 was collected from the Sand Coulee beds of the Willwood Formation in Clark Quadrangle, Wyoming (USA). These beds fall within the Plesiadapis cookei zone (biozone Cf-2) of the Clarkfordian North American Land Mammal Age (Houde and Olson, 1992). Biozone Cf-2 is located above the base of Chron C24r. Although Chron C24r spans the Paleocene-Eocene boundary, biozone Cf-2 occurs entirely within the Paleocene. Secord et al. (2006) obtained a weighted mean 40Ar/39Ar age of 59.00±0.30Ma for the Belt Ash, which occurs within the older Chron C26r. These authors used a cubic spline function to calibrate biozone boundaries to numerical dates, estimating the age of Cf-2 as between 56.60Ma and 56.22Ma. Together, the radiometric, paleomagnetic and biostratigraphic data provide a tightly constrained estimate for the appearance of Sandcoleus copiosus.
  node maximum age
0 Ma
None specified.
 primary fossil used to date this node 
USNM 433912
Sandcoleus copiosus, Houde and Olson, 1992
Location relative to the calibrated node: Stem

[show fossil details]
     Locality: Clark Quadrangle, Wyoming
     Stratum: Sand Coulee beds of the Willwood Formation
     Geological age: Paleocene, Paleogene, Cenozoic

More information in Fossilworks   PaleoBioDB

  phylogenetic justification
: Phylogenetic analysis of morphological data (Mayr and Mourer-Chauviré, 2004; Zelenkov and Dyke, 2008; Ksepka and Clarke, 2009, 2010c). Analyses utilizing a composite Sandcoleidae with scorings from Sandcoleus and several related taxa also support placing Sandcoleus copiosus along the mousebird stem lineage (Mayr and Mourer-Chauviré, 2004; Mayr, 2005d). No alternative hypothesis for a close relationship with an extant group other than mousebirds has been forwarded for Sandcoleus.
  phylogenetic reference(s)
Mayr, G. and Mourer-Chauviré, C. 2004. Unusual tarsometatarsus of a mousebird from the Paleogene of France and the relationships of Selmes Peters, 1999. Journal of Vertebrate Paleontology, 24: 366-372.
Zelenkov, N.V., and Dyke, G.J. 2008. The fossil record and evolution of mousebirds (Aves: Coliiformes). Palaeontology, 51:1403-1418.
Ksepka, D.T. and Clarke, J.A. 2009. Affinities of Palaeospiza bella and the phylogeny and biogeography of mousebirds (Coliiformes). Auk, 126: 245-259.
Ksepka, D.T. and Clarke, J.A. 2010. New fossil mousebird (Aves: Coliiformes) with feather preservation provides insight into the ecological diversity of an Eocene North American avifauna. Zoological Journal of the Linnean Society, 160: 685-706.
 tree image (click image for full size) 
tree image
Figure 9 of Ksepka and Clarke (2014): Phylogenetic tree showing position of Sandcoleus copiosus, illustrating the divergence calibrated by USNM 433912.