Chronogram for divergence of Bilateria (scroll down below figure to see table)

Range Table - link million years ago (Ma)
Organism Metazoa animals
Reference Gregory D. Edgecombe et al., Higher-level metazoan relationships: recent progress and remaining questions. Organisms Diversity & Evolution. June 2011, Volume 11, Issue 2, pp 151–172 p.157 table 1 and p.164 figure 4
Primary Source Dunn CW et al., Broad phylogenomic sampling improves resolution of the animal tree of life. Nature. 2008 Apr 10 452(7188):745-9. doi: 10.1038/nature06614PubMed ID18322464
Method Primary source abstract: "Here [investigators] report a total of 39.9 Mb of expressed sequence tags from 29 animals belonging to 21 phyla, including 11 phyla previously lacking genomic or expressed-sequence-tag data."
Comments P.163 right column bottom paragraph: "Figure 4 is a chronogram based on the most likely topology in the 64-taxon Bayesian analysis of Dunn et al. (primary source) using relaxed-clock methods for a 150-gene sample. Because of the substantial incongruence among the relationships between the main non-bilaterian lineages in phylogenomic studies to date (Fig. 1), the topology used for dating is for Bilateria alone." P.164 right column: "Calibration to constraints was performed by penalized likelihood (Sanderson 2002), as implemented in r8s v1.71 (Sanderson 2003), with a truncated Newton (TN) algorithm. The optimization of the smoothing parameter was obtained using the cross-validation feature in r8s following the instructions of the program manual (available at link note-link is broken). All analyses passed the gradient check implemented in r8s. Calibration points were assigned from minimum dates for branch points in the tree based on the oldest well-corroborated fossil(s) for clades with reliable palaeontological data (Table 1: Electronic supplementary material)." P.165 left column 2nd paragraph: "The resulting chronogram is consistent with Ediacaran origins for many animal phyla, and with dates of 598, 603 and 618 Mya for Ecdysozoa, Spiralia and Protostomia, respectively (Fig. 4)."
Entered by Uri M
ID 117103