Locality 22, Arroyo San Angel - Beal (1948) (Miocene to of Mexico)

Also known as Loc. 22

Where: Baja California Sur, Mexico (27.2° N, 113.3° W: paleocoordinates 26.4° N, 107.9° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Lower Member (Ysidro Formation), Early/Lower Miocene to Early/Lower Miocene (23.0 - 11.6 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.

• bed-level stratigraphic resolution

Environment/lithology: coastal; lithified, white sandstone

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

Size class: macrofossils

Preservation: mold/impression

Collection methods: quarrying,

• Collection studied and determined by J. Smith (Stanford). 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 43804: authorized by Austin Hendy, entered by Austin Hendy on 26.08.2004, edited by Mark Uhen

Creative Commons license: CC BY (attribution)

Taxonomic list

• Representative.
Gastropoda
 Cerithioidea - Turritellidae
Turritella (Broderiptella) sp.2 Olsson 1964 turret shell
Turritella aff. inezana Conrad 1857 turret shell
Bivalvia
 Arcida - Arcidae
"Arca aff. devincta" = Anadara (Anadara) devincta
"Arca aff. devincta" = Anadara (Anadara) devincta Conrad 1849 ark
 Arcida - Glycymerididae
Glycymeris sp. Da Costa 1778 clam
 Pectinida - Pectinoidae
"Pecten aff. keepi" = Euvola keepi
"Pecten aff. keepi" = Euvola keepi Arnold 1906 scallop
 Mytilida - Mytilidae
Mytilus sp. Linnaeus 1758 mussel
 Lucinida - Lucinidae
? Phacoides sp. Blainville 1825 clam
 Cardiida - Veneridae
"Chione cf. securis" = Securella securis, "Chione temblorensis" = Chione (Chionopsis) temblorensis
"Chione cf. securis" = Securella securis Shumard 1858 venus clam
"Chione temblorensis" = Chione (Chionopsis) temblorensis Anderson 1905 venus clam
 Cardiida - Cardiidae
Cardium sp. Linnaeus 1758 cockle
Thecostraca
 Balanomorpha - Balanidae
"Balanus concavus" = Concavus concavus
"Balanus concavus" = Concavus concavus Bronn 1831 barnacle
Echinoidea
  -
Echinoidea indet. Leske 1778 sea urchin
Mammalia
 Sirenia - Sirenia
Sirenia indet.1 sirenian