The Alsea Formation is a geologic formation in Oregon. It preserves fossils dating back to the Rupelian stage of the Oligocene period.[1]

Alsea Formation
Stratigraphic range: Rupelian (Whitneyan)
~33.7–30.6 Ma
TypeFormation
UnderliesYaquina Formation
Lithology
PrimarySiltstone
OtherMudstone
Location
Coordinates44°36′N 124°00′W / 44.6°N 124.0°W / 44.6; -124.0
Approximate paleocoordinates44°18′N 113°06′W / 44.3°N 113.1°W / 44.3; -113.1
RegionLincoln County, Oregon
Country United States
Alsea Formation is located in the United States
Alsea Formation
Alsea Formation (the United States)
Alsea Formation is located in Oregon
Alsea Formation
Alsea Formation (Oregon)

Fossil content edit

The following fossils have been reported from the formation:[1]

Mammals edit

Fish edit

See also edit

References edit

  1. ^ a b Alsea Formation at Fossilworks.org
  2. ^ Deméré & Berta, 2008
  3. ^ Peredo et al., 2018
  4. ^ Fordyce, 2002
  5. ^ Welton, 2016

Bibliography edit

  • Peredo, C. M.; N. D. Pyenson; C. D. Marshall, and M. D. Uhen. 2018. Tooth loss precedes the origin of baleen in whales. Current Biology 28. 1-9. .
  • Welton, B. J. 2016. First report of Orthechinorhinus (Squaliformes: Etmopteriidae) from the Pacific Basin; A new species from Early Oligocene rocks of Oregon, USA. Fossil Record 5. 303–308. .
  • Deméré, T. A., and A. Berta. 2008. Skull anatomy of the Oligocene toothed mysticete Aetiocetus weltoni (Mammalia; Cetacea): implications for mysticete evolution and functional anatomy. Zoological Journal of the Linnean Society 154. 308–352. .
  • Fordyce, R. E. 2002. Simocetus rayi (Odontoceti, Simocetidae, new family); a bizarre new archaic Oligocene dolphin from the eastern North Pacific. Smithsonian Contributions to Paleobiology 93. 185–222. .