comment on this calibration
Hemichordata
Lineage (NCBI):
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» Eukaryota
» Opisthokonta
» Metazoa
» Eumetazoa
» Bilateria
» Coelomata
» Deuterostomia
» Hemichordata
| node name Hemichordata Look for this name in NCBI Wikipedia Animal Diversity Web | ||
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recommended citations http://palaeo-electronica.org/content/fc-1 Benton et al. 2015 |
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node minimum age 504.5 Ma Rhabdotubus johanssoni was recovered from shales within the Eccaparadoxides pinus Zone (=Ptychagnostus praecurrens Zone) (Bengtson and Urbanek, 1986) which occurs within Cambrian Series 3, Age 5 (i.e. pre-Drumian) of GTS2012 (Peng et al., 2012). | ||
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node maximum age 636.1 Ma A soft maximum constraint is based on 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 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 out 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 | ||
SMNH Cn 67217 | ||
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phylogenetic justification
Rhabdotubus johanssoni exhibits clear evidence of cortical banding which demonstrates membership of total group, if not crown-Pterobranchia and, therefore, membership of crown-Hemichordata. |
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phylogenetic reference(s)
Bengtson, S., and Urbanek, A. 1986. Rhabdotubus, a Middle Cambrian rhabdopleurid hemichordate. Lethaia, 19:293-308.
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| tree image (click image for full size) | ||
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Figure 2 from Benton et al. (2014)
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