comment on this calibration


 node name
Malacostraca     Look for this name in NCBI   Wikipedia   Animal Diversity Web
  recommended citations
Wolfe et al. 2016
  node minimum age
429.8 Ma
This fossil is preserved as a carbonate concretion from the volcaniclastic Herefordshire Lagerstätte of Herefordshire, England, at the Sheinwoodian-Homerian stage boundary, within the Early Silurian Wenlock Series (Siveter, 2008). As the Homerian begins at 430.5 Ma ± 0.7 Myr, a minimum age constraint for the Herefordshire can thus be placed at 429.8 Ma.
  node maximum age
521 Ma
A soft maximum age is obtained from the oldest mandibulate, Y. dianensis, which was recovered from the Yu'anshan Formation at Xiaotan section, Yongshan, Yunnan Province, attributed to the Eoredlichia–Wutingaspis Biozone (Zhang et al., 2007). Chinese Cambrian stratigraphy has been revised substantially and the Eoredlichia –Wutingaspis Biozone is no longer recognized (Peng, 2003, 2009). However, Eoredlichia is known to co-occur with Hupeidiscus, which is diagnostic of the Hupeidiscus-Sinodiscus Biozone, which is formally recognized as the second biozone of the Nangaoan Stage of the Qiandongian Series of the Cambrian of China (Peng and Babcock,2008). The Nangaoan is the proposed third stage of the Cambrian System for the International Geologic Timescale (Peng et al., 2012a).Thus, a soft maximum constraint can be established on the age of the lower boundary of the Nangaoan, which has been dated to 521 Ma (Peng et al., 2012a; Peng and Babcock, 2008).
 primary fossil used to date this node 
OUM C.29565
Cinerocaris magnifica, Briggs et al., 2004
Location relative to the calibrated node: Crown

[show fossil details]
     Locality: Herefordshire Lagerstätte
     Geological age: Silurian, Paleozoic

More information in Fossilworks   PaleoBioDB

  phylogenetic justification
C. magnifica was found to be a member of the stem group of Leptostraca (therefore crown group Malacostraca) in analyses of morphology (Legg et al., 2013) and morphology combined with molecules (Oakley et al., 2013).
  phylogenetic reference(s)
Legg, D.A., Sutton, M.D., Edgecombe, G.D. 2013. Arthropod fossil data increase congruence of morphological and molecular phylogenies. Nature Communications 4, 2485.
Oakley, T.H.,Wolfe, J.M., Lindgren, A.R., and Zaharoff, A.K. 2013. Phylotranscriptomics to bring the understudied into the Fold: Monophyletic Ostracoda, fossil placement, and Pancrustacean phylogeny. Mol. Biol. Evol. 30, 215–233.
 tree image (click image for full size) 
tree image
Figure 13 from Wolfe et al. (2016)