Magnetic stratigraphy and tectonic rotation of the Eocene‐Oligocene Keasey Formation, northwest Oregon

Prothero, Donald R.; Hankins, Karina G.

doi:10.1029/2000jb900063

Cited by 32 publications

(47 citation statements)

References 32 publications

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“…Locality and Horizon-All specimens are float concretions that eroded from the beach terrace and low banks west of the mouth of Murdock Creek, south shore of Strait of Juan de Fuca, Clallam County, Washington, U.S.A. (GPS data: SMF Av 599: 48.1567 N, 123.8696 W;SMF Av 600: 48.1545 N, 123.8655 W;SMF Av 601: 48.1558 N, 123.8685 W); lower part of Pysht Formation, latest early Oligocene/early late Oligocene Prothero et al, 2001), or late Oligocene (Nesbitt et al, 2010).…”

Section: Methodsmentioning

confidence: 99%

Oligocene plotopterid skulls from western North America and their bearing on the phylogenetic affinities of these penguin-like seabirds

Mayr

Goedert

Vogel

2015

Journal of Vertebrate Paleontology

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Plotopterids are penguin-like, wing-propelled birds with controversial phylogenetic affinities. They are usually regarded as closely related to Suloidea (gannets, cormorants, and allies), with the penguin-like features considered to be of convergent origin. However, it has also been proposed that the similarities shared by plotopterids and penguins are due to common ancestry. An in-depth assessment of plotopterid affinities has been hampered by the fact that very little data about the skull of these birds were available. New fossils of Tonsala from the Oligocene Pysht Formation in Washington State (U.S.A.) include the first well-preserved cranial remains of this taxon. They show that although plotopterids share derived cranial features with members of Suloidea that are absent in species of Sphenisciformes (penguins), they lack diagnostic derived features of the representatives of crown group Suloidea. To assess the affinities of plotopterids, we performed a phylogenetic analysis that included, for the first time, early stem group representatives of Sphenisciformes, resulting in a sister-group relationship between Plotopteridae and Suloidea. Intriguingly, however, our reanalysis of the emended data of a more comprehensive recent analysis that supported a position of Plotopteridae within Suloidea recovered a sister-group relationship between Plotopteridae and Sphenisciformes. Although cranial morphology challenges the hypothesis of close affinities between plotopterids and penguins, more data on early stem lineage representatives of penguins are needed for a robust placement of Plotopteridae relative to Sphenisciformes.

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Section: Methodsmentioning

confidence: 99%

Oligocene plotopterid skulls from western North America and their bearing on the phylogenetic affinities of these penguin-like seabirds

Mayr

Goedert

Vogel

2015

Journal of Vertebrate Paleontology

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“…The divergence between Ursidae and the other Arctoidea was older than 39.6 Ma (the oldest fossil record of the superfamily Ursioidea Daphoenus sp., Hunt, 1998, see also Yonezawa et al, 2008). The divergence between Otarioidea (Otariidae + Odobenidae) and Phocidae was between 19.1 Ma (the oldest fossil record of the crown taxa of Pinnipedia, Desmatophoca brachycephala, Barnes, 1987) and 28.4 Ma (the oldest fossil record of the stem taxa of Pinnipedia, Enaliarctos tedfordi, Berta, 1991, see also Prothero et al, 2001;Kohno, 2005). The divergence between Otariidae and Odobenidae was older than 16.6 Ma (the oldest fossil record of family Odobenidae Proneotherium repenningi, Deméré et al, 2003, see also Kohno, 2005;Prothero et al, 2001).…”

Section: The Phylogenetic Analyses and The Divergence Time Estimationmentioning

confidence: 97%

“…The divergence between Otarioidea (Otariidae + Odobenidae) and Phocidae was between 19.1 Ma (the oldest fossil record of the crown taxa of Pinnipedia, Desmatophoca brachycephala, Barnes, 1987) and 28.4 Ma (the oldest fossil record of the stem taxa of Pinnipedia, Enaliarctos tedfordi, Berta, 1991, see also Prothero et al, 2001;Kohno, 2005). The divergence between Otariidae and Odobenidae was older than 16.6 Ma (the oldest fossil record of family Odobenidae Proneotherium repenningi, Deméré et al, 2003, see also Kohno, 2005;Prothero et al, 2001). The divergence between Phocinae and Monachinae was older than 14.4 Ma (the oldest fossil record of the Monachinae Monotherium wymani, Ray, 1976, see also Deméré et al, 2003).…”

Section: The Phylogenetic Analyses and The Divergence Time Estimationmentioning

confidence: 97%

The monophyletic origin of sea lions and fur seals (Carnivora; Otariidae) in the Southern Hemisphere

Yonezawa

Kohno

Hasegawa

2009

Gene

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“…The new fossil specimen (NMV P252567) comes from the upper part of the Pysht Formation (Clallam County, Washington State, USA; Late Oligocene) (Prothero et al, 2001), and comprises much of the cranium, both mandibles, and postcranial elements. Overall, the morphology of the skull is intermediate between that of Aetiocetus and Fucaia (Barnes et al, 1995).…”

Section: Description Of Nmv P252567mentioning

confidence: 99%

Suction feeding preceded filtering in baleen whale evolution

Marx

Hocking²,

Park³

et al. 2016

MMV

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Marx F.G., Hocking D.P., Park T., Ziegler T., Evans A.R. and Fitzgerald, E.M.G. 2016. Suction feeding preceded filtering in baleen whale evolution. Memoirs of Museum Victoria 75: 71-82.The origin of baleen, the key adaptation of modern whales (Mysticeti), marks a profound yet poorly understood transition in vertebrate evolution, triggering the rise of the largest animals on Earth. Baleen is thought to have appeared in archaic tooth-bearing mysticetes during a transitional phase that combined raptorial feeding with incipient bulk filtering. Here we show that tooth wear in a new Late Oligocene mysticete belonging to the putatively transitional family Aetiocetidae is inconsistent with the presence of baleen, and instead indicative of suction feeding. Our findings suggest that baleen arose much closer to the origin of toothless mysticete whales than previously thought. In addition, they suggest an entirely new evolutionary scenario in which the transition from raptorial to baleen-assisted filter feeding was mediated by suction, thereby avoiding the problem of functional interference between teeth and the baleen rack.

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Magnetic stratigraphy and tectonic rotation of the Eocene‐Oligocene Keasey Formation, northwest Oregon

Cited by 32 publications

References 32 publications

Oligocene plotopterid skulls from western North America and their bearing on the phylogenetic affinities of these penguin-like seabirds

Oligocene plotopterid skulls from western North America and their bearing on the phylogenetic affinities of these penguin-like seabirds

The monophyletic origin of sea lions and fur seals (Carnivora; Otariidae) in the Southern Hemisphere

Suction feeding preceded filtering in baleen whale evolution

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