Pysht Formation

Pysht Formation
Stratigraphic range: Late Oligocene, Chattian PreꞒ Ꞓ O S D C P T J K Pg N ↓
Fossil Callianopsis from the Pysht Formation
Type	Geological formation
Unit of	Twin River Group
Underlies	Clallam Formation
Overlies	Makah Formation
Lithology
Primary	Siltstone, mudstone, conglomerate
Location
Coordinates	48°12′N 123°54′W / 48.2°N 123.9°W / 48.2; -123.9
Approximate paleocoordinates	47°48′N 114°54′W / 47.8°N 114.9°W / 47.8; -114.9
Region	Washington
Country	United States
Type section
Named for	Pysht River

The Pysht Formation is a geologic formation in Washington (state). It preserves fossils dating back to the Paleogene period, which appear to have been deposited in an offshore marine environment. Outcrops are present on the northern Olympic Peninsula, in Clallam County.^[1]

Fossil content

Based on the Paleobiology Database:^[2]

Cartilaginous fish

Cartilaginous fish of the Pysht Formation
Genus	Species	Presence	Material	Notes	Images
Somniosus	S. gonzalezi			A sleeper shark.

Mammals

Mammals of the Pysht Formation
Genus	Species	Presence	Material	Notes	Images
cf. Allodesmus	A. sp.			A desmatophocid pinniped.
Behemotops	B. proteus			The most basal known desmostylian. Type locality for genus and species.
Borealodon	B. oseax			A stem-baleen whale. Type locality for genus and species.[3]
Fucaia	F. goedertorum			An aetiocetid baleen whale.
?Kronokotherium	K. sp.			A desmostylian.
Olympicetus	O. avitus		Two partial skulls belonging to a juvenile and a neonate, including part of the dentition and a tympanic bulla	A simocetid toothed whale. Type locality for genus and species.[4][5]
	O. thalassodon		Posterior part of skull
Pinnarctidion	P. iverseni		A nearly complete skull and limited postcrania (SDSNH 146624).[6]	A pan-pinniped.
Sitsqwayk	S. cornishorum		Partial skull, tympanic bullae, mandibles and postcrania.[7]	An basal baleen whale. Type locality for genus and species.[7]

Birds

Birds of the Pysht Formation
Genus	Species	Presence	Material	Notes	Images
Klallamornis	K. buchanani			A plotopterid suliform.[8]
Tonsala	T. hildegardae			A plotopterid suliform.[9]

Crustaceans

Crustaceans of the Pysht Formation
Genus	Species	Presence	Material	Notes	Images
Upogebia	U. barti	Locality RB 18.[10]	Multiple specimens.[10]	An upogebiid mud shrimp.

See also

• Earth sciences portal
• United States portal
• Paleontology portal

• List of fossiliferous stratigraphic units in Washington (state)
• Paleontology in Washington (state)

References

1. "Geolex — Pysht publications". ngmdb.usgs.gov. Retrieved 2024-11-19.
2. Czaplewski, John J. "PBDB Navigator". paleobiodb.org. Retrieved 2024-11-19.
3. Shipps, B. K.; Peredo, Carlos Mauricio; Pyenson, Nicholas D. (2019). "Borealodon osedax, a new stem mysticete (Mammalia, Cetacea) from the Oligocene of Washington State and its implications for fossil whale-fall communities". Royal Society Open Science. 6 (7) 182168. doi:10.1098/rsos.182168. ISSN 2054-5703. PMC 6689636. PMID 31417706.
4. Velez-Juarbe, J. (2017). "A new stem odontocete from the late Oligocene Pysht Formation in Washington State, U.S.A.". Journal of Vertebrate Paleontology. 37 (5) e1366916. Bibcode:2017JVPal..37E6916V. doi:10.1080/02724634.2017.1366916. S2CID 90151706.
5. Velez-Juarbe, J. (2023). "New heterodont odontocetes from the Oligocene Pysht Formation in Washington State, U.S.A., and a reevaluation of Simocetidae (Cetacea, Odontoceti)". PeerJ. 11 e15576. doi:10.7717/peerj.15576. PMC 10292202. PMID 37377790.
6. Everett, Christopher J.; Deméré, Thomas A.; Wyss, André R. (2023-03-23). "A new species of Pinnarctidion from the Pysht Formation of Washington State (U.S.A.) and a phylogenetic analysis of basal pan-pinnipeds (Eutheria, Carnivora)". Journal of Vertebrate Paleontology. 42 (3) e2178930. doi:10.1080/02724634.2023.2178930. ISSN 0272-4634. S2CID 257731013.
7. Peredo, Carlos Mauricio; Uhen, Mark D. (2016-11-01). "A new basal chaeomysticete (Mammalia: Cetacea) from the Late Oligocene Pysht Formation of Washington, USA". Papers in Palaeontology. 2 (4): 533–554. doi:10.1002/spp2.1051. ISSN 2056-2802.
8. Mayr, G.; Goedert, J. L. (2016). "Eocene and Oligocene remains of the flightless, penguin-like plotopterids (Aves, Plotopteridae) from Western Washington State". Journal of Vertebrate Paleontology. 36 (4): 1–18. Bibcode:2016JVPal..36E3573M. doi:10.1080/02724634.2016.1163573. S2CID 88129671.
9. Olson, S. L. (1980). "A new genus of penguin-like pelecaniform bird from the Oligocene of Washington (Pelecaniformes: Plotopteridae)". Contributions in Science. 330: 51–57. doi:10.5962/p.208144. S2CID 4803730.
10. Fraaije, R. (January 2006). "Two new Paleogene species of mud shrimp (Crustacea, Decapoda, Upogebiidae) from Europe and North America". Bulletin of the Mizunami Fossil Museum (33): 81–89.

• Various Contributors to the Paleobiology Database. "Fossilworks: Gateway to the Paleobiology Database". Retrieved 17 December 2021.