Locality 26, Arroyo Purisima - Beal (1948) (Miocene of Mexico)

Also known as Loc. 26

Where: Baja California Sur, Mexico (26.2° N, 112.3° W: paleocoordinates 25.3° N, 105.9° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Ysidro Formation, Early/Lower Miocene (23.0 - 16.0 Ma)

• The Ysidro Formation consists of dirty-white sandstone, underlying the Comondu Formation. The formation varies in lithology from place to place and apparently becomes more tuffaceous towards the gulf coast. The formation can be subdivided into two members, a lower shale member and an upper sandstone member. According to J. Smith this has lower Miocene affinities.

• bed-level stratigraphic resolution

Environment/lithology: coastal; white sandstone

• Shallow marine assemblage. No specific paleoenvironmental data presented.
• Dirty white sandstone.

Size class: macrofossils

Collection methods: quarrying,

• Collection studied and determined by J. Smith. 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: biostratigraphic analysis

PaleoDB collection 43811: authorized by Austin Hendy, entered by Austin Hendy on 26.08.2004

Creative Commons license: CC BY (attribution)

Taxonomic list

• Representative.
Gastropoda
 Neotaenioglossa - Calyptraeidae
"Trochita costellata" = Calyptraea costellata
"Trochita costellata" = Calyptraea costellata Conrad 1857 slipper shell
 Cerithioidea - Turritellidae
Turritella tristis turret shell
Turritella cf. margaritana Nomland 1917 turret shell
Turritella cf. ocoyana Conrad 1855 turret shell
 Neogastropoda - Muricidae
"Rapana vaquerosensis" = Califrapana vaquerosensis
"Rapana vaquerosensis" = Califrapana vaquerosensis Arnold 1908 murex snail
 Sorbeoconcha - Strombidae
Strombus sp. n. sp.
Strombus sp. n. sp. Linnaeus 1758 conch
Listed as "Strombus sp. nov."
Bivalvia
 Cardiida - Veneridae
Chione sp. von Mühlfield 1811 venus clam
 Carditida - Carditidae
"Venericardia cf. californica" = Coanicardita californica
"Venericardia cf. californica" = Coanicardita californica Dall 1903 clam
 Pectinida - Pectinoidae
"Pecten cf. crassicardo" = Lyropecten crassicardo, Pecten aff. lecontei
"Pecten cf. crassicardo" = Lyropecten crassicardo Conrad 1856 scallop
Pecten aff. lecontei Arnold 1906 scallop
Listed as "Pecten sp. nov. aff. P. lecontei"
 Ostreida - Ostreidae
 Arcida - Arcidae
"Arca cf. osmonti" = Anadara osmonti
"Arca cf. osmonti" = Anadara osmonti Dall 1909 ark
Thecostraca
 Balanomorpha - Balanidae
"Balanus concavus" = Concavus concavus
"Balanus concavus" = Concavus concavus Bronn 1831 barnacle