comment on this calibration


 node name
Atlantogenata     Look for this name in NCBI   Wikipedia   Animal Diversity Web
  recommended citations Benton et al. 2015
  node minimum age
56 Ma
The minimum age estimate is based on the occurrence of Eritherium in the Sidi Chennane quarries, phosphate bed IIa, lower bone-bed, Ouled Abdoun Basin of Morocco, regarded as upper Paleocene (early Thanetian; Gheerbrant, 2009), whose upper bound is dated as 56.0 Ma ± 0.0 Myr (Gradstein et al., 2012).
  node maximum age
164.6 Ma
The soft maximum date is based on the divergence of Eutheria from other mammals in the late Jurassic, represented by Juramaia (Luo et al., 2011). This taxon is represented in the Daxigou site of the Tiaojishan Formation, Liaoning Province, Northeastern China, and has been constrained by radiometric dates to derive from deposits of just over 160 Ma in age (Luo et al., 2011). The equivalent marine stage is the Oxfordian (Gradstein et al., 2012), with a lower boundary of 163.5 Ma ± 1.1 Myr, and thus 164.6 Ma is a soft maximum.
 primary fossil used to date this node 
Eritherium azzouzorum , Gheerbrant, 2009
Location relative to the calibrated node: Crown

[show fossil details]
     Locality: Sidi Chennane quarries
     Stratum: phosphate bed IIa, lower bone-bed, Ouled Abdoun Ba
     Geological age: Paleocene, Paleogene, Cenozoic

More information in Fossilworks   PaleoBioDB

  phylogenetic justification
Eritherium is classed as a proboscidean based on numerous dental and cranial synapomorphies (Gheerbrant, 2009): I1 enlarged, larger than I2, I1–2 with high (styliform), labio-lingually compressed, asymmetric, and procumbent crown; I3 strongly reduced; C1 very small; (d)P1 small and simple; molar hypoconulid labial; coronoid retromolar fossa enlarged. As a proboscidean, Eritherium is then a member of wider clades Paenungulata, Afrotheria, and Atlantogenata.
  phylogenetic reference(s)
Gheerbrant, E. 2009. Paleocene emergence of elephant relatives and the rapid radiation of African ungulates. Proceedings of the National Academy of Sciences, USA, 106:10717-10721.
 tree image (click image for full size) 
tree image