comment on this calibration


 node name
Myriapoda     Look for this name in NCBI   Wikipedia   Animal Diversity Web
  recommended citations
Wolfe et al. 2016
  node minimum age
424.7 Ma
The earliest myriapods in the body fossil record are three species of Diplopoda from the Dictyocaris Member of the Cowie Formation at Cowie Harbour, near Stonehaven, Aberdeenshire, Scotland, one of which is C. eroticopodus (Wilson and Anderson, 2004). Based on associated spores, the Cowie Formation taxa are late Wenlock to early Ludlow in age (Marshall, 1991; Wellman, 1993) and the Early Ludlow upper boundary (Gorstian-Ludfordian boundary) is 425.6 Ma ± 0.9 Myr, so the minimum age for Myriapoda is 424.7 Ma.
  node maximum age
636.1 Ma
A soft maximum constraint is based on that used by Benton et al.(2015), the maximum age interpretation of the Lantian Biota (Yuan et al., 2011). This, together with the Doushantuo Biota (Yuan et al.,2002), provides a series of Konservat-Lagerstätten preserving the biota in Orsten- and Burgess Shale-like modes of fossilization. None of these Lagerstätten, least of all the Lantian, preserves anything that could possibly be interpreted as even a total group eumetazoan and on this basis we define our soft maximum constraint at 635.5 Ma ±0.6 Myr (Condon et al., 2005) and, thus, 636.1 Ma.
 primary fossil used to date this node 
AMS F.64845
Cowiedesmus eroticopodus, Wilson and Anderson, 2004
Location relative to the calibrated node: Crown

[show fossil details]
     Locality: Cowie Harbour
     Stratum: DictyocarisMember of the Cowie Formation
     Geological age: Silurian, Paleozoic

More information in Fossilworks   PaleoBioDB

  phylogenetic justification
Membership of C. eroticopodus in Diplopoda is indicated by its strict diplosegmentation,whereas its cuticular mineralization supports membership in the subgroup Chilognatha, and its modified legs on trunk segment 8 support membership in Helminthomorpha. C. eroticopodus is resolved as total-group Helminthomorpha in the morphological cladistic analysis of Fernández et al. (2016) and is accordingly a member of the crown-groups of Chilognatha, Diplopoda, Progoneata and Myriapoda.
  phylogenetic reference(s)
Fernández, R., Edgecombe, G.D., and Giribet, G. 2016. Exploring phylogenetic relationships within Myriapoda and the effects of matrix composition and occupancy on phylogenomic reconstruction. Systematic Biology 65:871-889.
 tree image (click image for full size) 
tree image
Figure 1 from Wolfe et al. (2016).