The Mission Valley Formation is a marine sandstone geologic formation in the Mission Valley region of southwestern San Diego County, California.[1][2]

Geology

The formation's sandstone characteristics are: soft and friable, light olive gray, fine to medium grained, and composed mostly of quartz and potassium feldspar.[1] The Mission Valley Formation thins from the west to the east, with a maximum thickness of 0–60 metres (0–197 ft).[1]

It overlies the Stadium Conglomerate formation and underlies the Pomerado Conglomerate formation.[1]

Fossil content

It preserves fossils dating back to the Paleogene period of the Cenozoic Era.[3] The formation's rocks can contain a molluscan fauna in the western and central exposures and a land-mammal fauna in the eastern exposures.[1]

Mammals

Eulipotyphlans

Eulipotyphlans reported from the Mission Valley Formation
Genus Species Presence Material Notes Images
Proterixoides P. davisi Several calcaneums, astragali and a navicular.[4]

Ferae

Ferae reported from the Mission Valley Formation
Genus Species Presence Material Notes Images
Ceruttia C. sandiegoensis "SDSNH locality 4888, State Road 125 North (Unit II, Mid Brown Siltstone)".[5] SDSNH 92504 and SDSNH 92503.[5] A carnivoraform.
cf. 'Miacis' cf. 'M.' hookwayi SDSNH locality 4715, State Route 125 Grossmont.[5] SDSNH 84969 "right dentary fragment with p2, m1, and m2".[5] A miacid.
Procynodictis P. progressus SDSNH locality 3870, Scripps Ranch North Site 70.[5] "SDSNH 54413 (left dentary fragment with p2-m2); SDSNH 54414 (right dentary fragment with m1-2); SDSNH 54416 (left maxillary fragment with P4-M1)".[5] A miacid.

Primatomorphs

Primatomorphs reported from the Mission Valley Formation
Genus Species Presence Material Notes Images
Hemiacodon H. sp. V-72157.[6] Isolated fragmentary teeth.[6] An omomyid, most similar to H. gracilis.
?Macrotarsius ?M. sp. V-72150 & V-73138.[6] Isolated molars.[6] An omomyid also known from the Friars Formation, closely similar to M. jepseni.
Microsyops M. sp. cf. M. annectens V-72158.[6] Isolated & fragmentary molar (UCMP 101619).[6] A microsyopid.
Notharctus N. sp. V-72157.[6] Damaged isolated molar (UCMP 113256).[6] A notharctine similar to N. robustior.
Omomys O. powayensis V-71180, V-72157 & V-72158.[6] Teeth.[6] An omomyid also known from the Friars Formation.
Pelycodus P. sp. V-73138.[6] Maxillary fragment (UCMP 113210).[6] A notharctine.
Uintasorex U. montezumicus V-71180, V-71211, V-72157, V-72158, V-72176, V-72177, V-72179, V-73138 & V-73139.[6] Isolated teeth.[6] A microsyopid also known from the Friars Formation.
Walshina W. esmaraldensis SDSNH localities 3426 and 4020.[7] Teeth.[7] An omomyid also known from the Sespe & Santiago formations.
Washakius W. woodringi V-71211, V-72157, V-72158, V-72176, V-72179 & V-73138.[6] Teeth & jaw elements.[6] An omomyid also known from the Friars Formation.


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. ^ PENKROT, TONYA A.; ZACK, SHAWN P. (2016). "Tarsals of Sespedectinae (?Lipotyphla) from the Middle Eocene of Southern California, and the Affinities of Eocene 'Erinaceomorphs'". Journal of Vertebrate Paleontology. 36 (6): e1212059. Bibcode:2016JVPal..36E2059P. doi:10.1080/02724634.2016.1212059. ISSN 0272-4634. JSTOR 44865966.
  5. ^ a b c d e f 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.
  6. ^ a b c d e f g h i j k l m n o p Lillegraven, Jason A. (1980). "Primates from Later Eocene Rocks of Southern California". Journal of Mammalogy. 61 (2): 181–204. doi:10.2307/1380040. ISSN 0022-2372. JSTOR 1380040.
  7. ^ a b López-Torres, Sergi; Silcox, Mary T.; Holroyd, Patricia A. (2018-09-22). "New omomyoids (Euprimates, Mammalia) from the late Uintan of southern California, USA, and the question of the extinction of the Paromomyidae (Plesiadapiformes, Primates)". Palaeontologia Electronica. 21 (3): 1–28. doi:10.26879/756. ISSN 1094-8074.

Further reading


Allikas: Https://en.wikipedia.org/wiki/Mission_Valley_Formation
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