comment on this calibration
Laurasiatheria
Lineage (NCBI):
root
» Eukaryota
» Opisthokonta
» Metazoa
» Eumetazoa
» Bilateria
» Coelomata
» Deuterostomia
» Chordata
» Craniata <chordata>
» Vertebrata <Metazoa>
» Gnathostomata <vertebrate>
» Euteleostomi
» Sarcopterygii
» Tetrapoda
» Amniota
» Mammalia
» Theria <Mammalia>
» Eutheria
» Laurasiatheria
| node name Laurasiatheria 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 61.6 Ma The Ravenscrag Formation is early Puercan in age, corresponding to the earliest part of the Danian (Gradstein et al., 2012, p. 400). To be conservative, we treat this as broadly early Paleocene (Danian) in age, with the top corresponding to an age of 61.7 Ma ± 0.1 Myr, hence 61.6 Ma. | ||
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node maximum age 164.6 Ma The soft maximum date is based on the divergence of Eutheria from other mammals in the late Jurassic, represented by Juramaia (Luo et al., 2011). This taxon is represented in the Daxigou site of the Tiaojishan Formation, Liaoning Province, Northeastern China, and has been constrained by radiometric dates to derive from deposits of just over 160 Ma in age (Luo et al., 2011). The equivalent marine stage is the Oxfordian (Gradstein et al., 2012), with a lower boundary of 163.5 Ma ± 1.1 Myr, and thus 164.6 Ma is a soft maximum. | ||
| primary fossil used to date this node | ||
UALVP 31175 | ||
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phylogenetic justification
Ravenictis is identified as a carnivoran based on synapormorphies of M1 shared with viverravids including the asymmetry of the crown, the proportions of the cusps, virtually identical wear patterns, and the development of the protocone cingula (Fox and Youzwyshyn, 1994; Fox et al., 2010). |
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phylogenetic reference(s)
Fox, R. C. and G. P. Youzwyshyn. 1994. New primitive carnivorans (Mammalia) from the Paleocene of western Canada, and their bearing on the relationships of the order. Journal of Vertebrate Paleontology, 14: 382-404.
Fox, R.C., Scott, C.S., and Rankin, B.D. 2010. New early carnivoran specimens from the Puercan (earliest Paleocene) of Saskatchewan, Canada. Journal of Paleontology, 84:1035-1039.
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| tree image (click image for full size) | ||
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