comment on this calibration


Lineage (NCBI): root » Eukaryota » Opisthokonta » Metazoa » Coelomata » Gnathostoma
 node name
Primates     Look for this name in NCBI   Wikipedia   Animal Diversity Web
  recommended citations Benton et al. 2015
  node minimum age
56 Ma
Altiatlasius comes from the Adrar Mgorn 1 locality in the Ouarzazate Basin of Morocco, dated generally as late Paleocene (Thanetian stage). Magnetostratigraphic study (Gheerbrant et al., 1998) narrows the age range of the locality to “late or latest Thanetian,” and so the age of the top of the Thanetian Stage (56 Ma ± 0.0 Myr = 56 Ma, Gradstein et al., 2012) provides the minimum constraint.
  node maximum age
66 Ma
The soft maximum constraint may be marked by older possible primate fossils. McKenna and Bell (1997) implied in their classification that carpolestids, with a record in the Danian (early Paleocene) are euprimates, but this has not been substantiated elsewhere. They also attribute the basal Paleocene Decoredon from China to Primates (following Szalay and Li, 1986), although this is disputed; Kondrashov and Lucas (2004) suggested affinities to the poorly understood group Anagalidae instead. In general, early Paleocene strata have yielded fossils of several groups (plesiadapids, paromomyids, carpolestids) reconstructed closer to crown primates than to Scandentia or Dermoptera (Bloch et al., 2007), but no definitive crown primates. Hence, the paleontological soft maximum constraint can be defined as the base of the Paleocene, at 66.04 Ma ± 0.4 Myr = 66 Ma.
 primary fossil used to date this node 
Altiatlasius koulchii , Sigé et al. 1990
Location relative to the calibrated node: Crown

[show fossil details]
     Locality: Adrar Mgorn 1
     Geological age: Cambrian, Paleozoic

More information in Fossilworks   PaleoBioDB

  phylogenetic justification
Cladistic analyses by Seiffert et al. (2005) and Tabuce et al. (2009) indicate that Altiatlasius is a member of crown Primates, and may even be a stem anthropoid.
  phylogenetic reference(s)
Seiffert, E.R., Simons, E.L., Clyde, W.C., Rossie, J.B., Attia, Y., Bown, T.M., Chatrath, P., and Mathison, M.E. 2005. Basal anthropoids from Egypt and the antiquity of Africa's higher primate radiation. Science, 310:300-304.
 tree image (click image for full size) 
tree image
Figure 11 of Benton et al (2014).