UCMP 7004, Simi Valley: Lutetian, California
collected by R. B. Stewart
List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
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Cephalopoda
- Nautilida
- Aturiidae
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Aturia myrlae
(Hanna 1927)
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| (1 measurement) | ||||||||||
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Gastropoda
- Turritellidae
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Turritella andersoni
Dickerson 1916
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Merriam 1941 | |||||||||
| as Turritella andersoni subsp. lawsoni | ||||||||||
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Turritella uvasana
Conrad 1855
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Merriam 1941 | |||||||||
| as Turritella uvasana subsp. etheringtoni | ||||||||||
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Gastropoda
- Ampullinidae
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Globularia hannibali
(Dickerson 1914)
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Clark 1934 | |||||||||
| recombined as Eocernina hannibali | ||||||||||
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Amaurellina clarki
(Stewart 1927)
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Clark 1934 | |||||||||
| recombined as Pachycrommium clarki | ||||||||||
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Gastropoda
- Neogastropoda
- Turridae
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Surculites mathewsonii
(Gabb 1864)
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Clark 1934 | |||||||||
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Gastropoda
- Neogastropoda
- Volutidae
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Volutocorbis lajollaensis
(Hanna 1927)
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Clark 1934 | |||||||||
| recombined as Lyrischapa lajollaensis | ||||||||||
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Gastropoda
- Cassidae
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Galeodea (Caliagaleodea) californica n. sp.
Clark 1942
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Squires 2019 | |||||||||
| recombined as Galeodea californica | ||||||||||
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Bivalvia
- Ostreida
- Malleidae
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Exputens llajasensis n. sp.
Clark 1934
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Squires 1984 | |||||||||
| recombined as Nayadina (Exputens) llajasensis | ||||||||||
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Bivalvia
- Ostreida
- Ostreidae
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Ostrea idriaensis
Gabb 1869
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Clark 1934 | |||||||||
| recombined as Acutostrea idriaensis | ||||||||||
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Bivalvia
- Carditida
- Crassatellidae
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Crassatellites indentata
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Clark 1934 | |||||||||
| synonym of Crassatella | ||||||||||
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Bivalvia
- Carditida
- Carditidae
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Venericardia hornii
(Gabb 1864)
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Clark 1934 | |||||||||
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= Venericardia (Pacificor) calafia n. sp.
Stewart 1930
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Verástegui 1953 | |||||||||
| type locality of subspecies, raised to species rank by Verástegui 1953 | ||||||||||
| see common names | ||||||||||
Geography
| Country: | United States | State/province: | California | County: | Ventura |
| Coordinates: | 34.3° North, 118.7° West (view map) | ||||
| Paleocoordinates: | 35.1° North, 104.6° West | ||||
| Basis of coordinate: | estimated from map | ||||
| Geographic resolution: | outcrop |
Time
| Period: | Paleogene | Epoch: | Eocene |
| Stage: | Lutetian | 10 m.y. bin: | Cenozoic 2 |
| Key time interval: | Lutetian | ||
| Age range of interval: | 47.80000 - 41.20000 m.y. ago |
Stratigraphy
| Formation: | Llajas | ||||
| Stratigraphic resolution: | group of beds | ||||
| Stratigraphy comments: From the "Domengine" horizon of the Eocene of Simi Valley. | |||||
Lithology and environment
| Primary lithology: | fine,brown,yellow lithified sandstone |
| Environment: | transition zone/lower shoreface |
| Geology comments: The "Stewart bed" is located in a section of transition from shallow-marine to outer slope and shelf facies. A nearshore environment is interpreted for that portion of the shallow-marine (transgressive) facies which consists of laminated beds alternating with bioturbated beds. In such cases, the finely laminated sand represents storm-influenced stratification, and the biogenic reworking is the inter-storm activity. Shell fragments commonly are concentrated as channel lags in surge channels. Fossils were apparently subjected to wave action because the apices of elongate shells such as Turritella are bimodally oriented in opposite directions. The deeper the water, the less amount of laminated sandstone and the more amount of bioturbated sandstone. Such areas, which were farther below effective wave base, existed 1) where the shallow-marine (transgressive) facies grades into the outer shelf to slope facies and 2) in the shallow-marine (regressive) facies. One of the deepest-water shallow-marine beds was the "Stewart bed." | |
Taphonomy
| Modes of preservation: | body |
| Size of fossils: | macrofossils |
Collection methods and comments
| Reason for describing collection: | taxonomic analysis |
| Museum repositories: | UCMP |
| Collectors: | R. B. Stewart |
Metadata
| Database number: | 166460 | ||
| Authorizer: | M. Clapham, P. Holroyd, J. Marcot | Enterer: | K. Okamoto, P. Holroyd, J. Marcot |
| Modifier: | M. Clapham | Research group: | marine invertebrate |
| Created: | 2015-02-14 02:52:07 | Last modified: | 2019-08-18 20:04:11 |
| Access level: | the public | Released: | 2015-02-14 02:52:07 |
| Creative Commons license: | CC BY |
Reference information
Primary reference:
| 54367. | H. G. Schenck. 1931. Cephalopods of the genus Aturia from western North America. University of California Publications, Bulletin of the Department of Geological Sciences 19:435-490 [M. Clapham/K. Okamoto/M. Clapham] |
Secondary references:
| 70889 | B. L. Clark. 1934. A New Genus and Two New Species of Lamellibranchiata from the Middle Eocene of California. Journal of Paleontology 8(3):270-272 [J. Marcot/J. Marcot] | |
| 24235 | C. W. Merriam. 1941. Fossil Turritellas from the Pacific Coast region of North America. University of California Publications Bulletin of the Department of Geological Sciences 26(1):1-214 [A. Hendy/A. Hendy] | |
| 59877 | R. L. Squires. 1984. Megapaleontology of the Eocene Llajas Formation, Simi Valley, California. Contributions in Science, Natural History Museum of Los Angeles County 350:1-76 [M. Clapham/M. Clapham] | |
| 68679 | R. L. Squires. 2019. Revision of Eocene warm-water cassid gastropods from coastal southwestern North America: implications for paleobiogeographic distribution and faunal-turnover. PaleoBios 36:1-22 [P. Holroyd/P. Holroyd] | |
| 71416 | P. Verástegui. 1953. The pelecypod genus Venericardia in the Paleocene and Eocene of western North America. Palaeontographica Americana 3(2535):399-462 [J. Marcot/J. Marcot] |