Cetacea Brisson 1762 ...
CROWN CETACEA (72) Node Calibrated. Divergence of baleen and toothed whales. Fossil Taxon and Specimen. Llanocetus denticrenatus (USNM 183022; Mitchell, 1989) from the Eocene La Meseta Formation of Seymour Island, Antarctica (Mitchell, 1989). Phylogenetic Justification. Phylogenetic analysis of livi...
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| Format: | Text |
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Zenodo
2015
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| Online Access: | https://dx.doi.org/10.5281/zenodo.13305948 https://zenodo.org/doi/10.5281/zenodo.13305948 |
| Summary: | CROWN CETACEA (72) Node Calibrated. Divergence of baleen and toothed whales. Fossil Taxon and Specimen. Llanocetus denticrenatus (USNM 183022; Mitchell, 1989) from the Eocene La Meseta Formation of Seymour Island, Antarctica (Mitchell, 1989). Phylogenetic Justification. Phylogenetic analysis of living and fossil mysticetes (Steeman, 2007) shows that Llanocetus is the closest relative of the toothless mysticetes (Chaeomysticeti Mitchell, 1989), based on two apomorphies: the premaxilla is straight in lateral view (not abruptly depressed anterior to nasals), and the occipital condyles are not situated on a swelling, but are rather levelled with the skull. Minimum Age. 33.9 Ma Soft Maximum Age. 56 Ma Age Justification. The upper La Meseta Formation of Seymour Island, Antarctica is dated as latest Priabonian (late Eocene) on the basis of a wide variety of fossils, including palynomorphs (Mitchell, 1989). Elsewhere, the La Meseta Formation appears to be restricted in age to the eaely Eocene (Ypresian), but upper ... : Published as part of Benton, MJ, Donoghue, PCJ, Vinther, J, Asher, RJ, Friedman, M & Near, TJ, 2015, Constraints on the timescale of animal evolutionary history, pp. 1-107 in Palaeontologia Electronica (Florence, Italy) (Florence, Italy) 15 (1) on pages 67-68, DOI: 10.26879/424, http://zenodo.org/record/13310890 ... |
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