Pomerado Conglomerate

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
Country United 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

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

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

Ferae

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

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

References

  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". 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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