comment on this calibration


 node name
Proboscidea     Look for this name in NCBI   Wikipedia   Animal Diversity Web
  recommended citations Benton et al. 2015
  node minimum age
5.33 Ma
The oldest crown proboscideans are represented by cheek teeth from the upper Miocene, including the Lukeino Formation (Kenya) and Toros Menalla (Chad). While Toros Menalla is likely older, both correlate to the Messinian marine stage with a minimum bound of 5.33 Ma (Sanders et al., 2010; Gradstein et al., 2012).
  node maximum age
23.03 Ma
Paleogene strata have yielded abundant proboscidean remains, spanning the upper Paleocene (Gheerbrant, 2009) through the early Miocene (Sanders et al., 2010). Sediments prior to the Miocene lack any fossils remotely similar to members of Elephantinae. Hence, we define the paleontological soft maximum constraint as the Oligocene-Miocene boundary, equivalent to the base of the Aquitanian marine stage at 23.03 Ma.
 primary fossil used to date this node 
KNM LU 916
Loxodonta sp., NO REFERENCE
Location relative to the calibrated node: Crown

[show fossil details]
     Locality: Lukeino Formation
     Stratum: Lukeino Formation
     Geological age: Miocene, Neogene, Cenozoic

  phylogenetic justification
Following Sanders et al. (2010), isolated teeth from the African sites mentioned above exhibit loxodont apomorphies, including propeller or lozenge shaped wear patterns.
  phylogenetic reference(s)
Sanders, W. J., Gheerbrant, E., Harris, J. M., Saegusa, H. & Delmer, C. (2010) Proboscidea. In: Cenozoic Mammals of Africa, (Werdelin, L. & Sanders, W. J., eds.). pp. 161-251. University of California Press, Berkeley.
 tree image (click image for full size) 
tree image