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Pomerado Conglomerate

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Pomerado Conglomerate Formation
Stratigraphic range: Late Eocene
TypeGeologic formation
OverliesMission Valley Formation
Thickness0–55 metres (0–180 ft)
Lithology
Primaryconglomerate
Location
RegionSan Diego County, California
CountryUnited States
Type section
Named forPomerado Road

The Pomerado Conglomerate Formation is a geologic formation in southwestern San Diego County, California.[1][2]

It was named for exposures located along Pomerado Road, at the divide between Carroll Canyon and Poway Valley.[1]

Geology

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The Pomerado Conglomerate is of the Late Eocene Epoch, and is a massive cobble conglomerate. It is lithologically identical to the local Stadium Conglomerate.[1]

It overlies the sandstone Mission Valley Formation.[1] It is the uppermost formation of the Poway Group, and has a maximum thickness of 55 metres (180 ft).[1]

Fossil content

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Color key
Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon
Notes
Uncertain or tentative taxa are in small text; crossed out taxa are discredited.

The Pomerado Conglomerate preserves fossils dating back to the Late Eocene Epoch of the Paleogene period, during the Cenozoic Era.[3]

Mammals

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Ferae

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Ferae reported from the Pomerado Conglomerate
Genus Species Presence Material Notes Images
Carnivoraformes undet. Genus B SDSNH locality 3757, Scripps Ranch North Site 57, Miramar Sandstone Member.[4] SDSNH 56335, cranium with right and left P4-M2.[4]
Hyaenodon cf. H. sp. Upper Member.[5] "SDSNH 60554, right maxillary fragment with P3–P4".[5] Specimen reidentified as the nimravid Pangurban.
Pangurban P. egiae Upper Member.[5] "SDSNH 60554, right maxillary fragment with P3–P4".[5] A nimravid, originally reported as cf. Hyaenodon sp.

Rodents

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Rodents reported from the Pomerado Conglomerate
Genus Species Presence Material Notes Images
Nonomyinae Indeterminate Isolated m1 (SDSNH 72232).[6] "An unnamed new taxon of nonomyine morphologically intermediate between Nonomys and Diplolophus."[6]
Nonomys N. gutzleri Isolated teeth.[6] A myomorph.


See also

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References

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  1. ^ a b c d e Kennedy, Michael P. (1975). Geology of the San Diego metropolitan area, California. California Division of Mines and Geology.
  2. ^ Geiconsultants.com: Geologic Formations of Western San Diego County[permanent dead link], by Jeffrey D. Brown, R.G., C.E.G. − circa 1996.
  3. ^ Various Contributors to the Paleobiology Database. "Fossilworks: Gateway to the Paleobiology Database". Archived from the original on 19 August 2022. Retrieved 17 December 2021.
  4. ^ a b Tomiya, Susumu (2013-05-20). "New carnivoraforms (Mammalia) from the middle Eocene of California, USA, and comments on the taxonomic status of 'Miacis' gracilis". Palaeontologia Electronica. 16 (2): 1–14. doi:10.26879/364. ISSN 1094-8074.
  5. ^ a b c d Poust, Ashley W.; Barrett, Paul Z.; Tomiya, Susumu (2022). "An early nimravid from California and the rise of hypercarnivorous mammals after the middle Eocene climatic optimum". Biology Letters. 18 (10): 20220291. doi:10.1098/rsbl.2022.0291. hdl:2433/276689. PMC 9554728. S2CID 252818430.
  6. ^ a b c Walsh, Stephen L. (September 2010). "New myomorph rodents from the Eocene of Southern California". Journal of Vertebrate Paleontology. 30 (5): 1610–1621. Bibcode:2010JVPal..30.1610W. doi:10.1080/02724634.2010.501433. S2CID 129569996.

Further reading

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