Locality 9, Punta San Ysidro - Beal (1948) (Paleocene of Mexico)

Also known as Loc. 9

Where: Baja California Sur, Mexico (31.3° N, 116.4° W: paleocoordinates 35.5° N, 95.9° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Tepetate Formation, Paleocene (66.0 - 56.0 Ma)

• Paleocene and Eocene series are named the Tepetate Formation in Baja California. The strata probably underlie a large part of the region covered by latter rocks, the uppermost beds lapping over the edges of the older formations and lying on the granite of the main range. Related to both Martinez (Paleocene) and Tejon) Eocene) of Californa, although further work suggests Paleocene faunal affinities are stronger.

• bed-level stratigraphic resolution

Environment/lithology: deltaic; fine-grained, yellow siltstone and sandstone

• The formation shows strong evidence of being a delta and near-shore deposit.
• In many places it is composed largely of fine yellow silt and contains sandstone beds with mammoth cross-bedding.

Size class: macrofossils

Collection methods: quarrying,

• Collection studied and determined by J. Smith (Stanford) and Stewart (USGS). No known repository.

Primary reference: C. H. Beal. 1948. Reconnaissance of the geology and oil possibilities of Baja California, Mexico. Geological Society of America Memoir 31 [A. Miller/A. Hendy/A. Hendy]more details

Purpose of describing collection: general faunal/floral analysis

PaleoDB collection 43762: authorized by Austin Hendy, entered by Austin Hendy on 25.08.2004

Creative Commons license: CC BY (attribution)

Taxonomic list

• Representative.
Gastropoda
 Cerithioidea - Turritellidae
"Turritella cf. martinezensis" = Mesalia martinezensis, Turritella cf. pachecoensis
"Turritella cf. martinezensis" = Mesalia martinezensis Gabb 1869 turret shell
Turritella cf. pachecoensis Stanton 1896 turret shell
 Neogastropoda - Melongenidae
"Neptunea cf. mucronata" = Sycum mucronatum
"Neptunea cf. mucronata" = Sycum mucronatum Gabb 1869 snail
 Sorbeoconcha - Ficidae
Urosyca caudata Gabb 1869 fig shell
 Sorbeoconcha - Naticidae
Amauropsis sp. Mörch 1857 moon snail
between A. martinezensis and A. alveata
Sinum cf. obliquum Gabb 1864 moon snail
 Opisthobranchia - Cylichnidae
"Cylichna costata" = Scaphander (Mirascapha) costatus
"Cylichna costata" = Scaphander (Mirascapha) costatus Gabb 1864 snail
Bivalvia
 Arcida - Cucullaeidae
"Cucullaea mathewsoni" = Cucullaea mathewsonii
"Cucullaea mathewsoni" = Cucullaea mathewsonii Gabb 1864 clam
 Pectinida - Anomiidae
"Placunanomia cf. inornata" = Anomia inornata
"Placunanomia cf. inornata" = Anomia inornata Gabb 1864 jingle
 Ostreida - Ostreidae
"Ostrea aff. appressa" = Striostrea appressa
"Ostrea aff. appressa" = Striostrea appressa Gabb 1869 oyster
 Carditida - Crassatellidae
"Crassatellites aff. branneri" = Crassatella branneri
"Crassatellites aff. branneri" = Crassatella branneri Waring 1914 clam
Scaphopoda
 Dentaliida - Dentaliidae
"Dentalium cooperii" = Dentalium cooperi
"Dentalium cooperii" = Dentalium cooperi Gabb 1864 tusk shell