Locality 22, Arroyo San Angel - Beal (1948): Early/Lower Miocene - Middle Miocene, Mexico

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Gastropoda - Turritellidae
Turritella aff. inezana Conrad 1857
Turritella aff. variegata (Linnaeus 1758)
    = Turritella (Broderiptella) sp. Olsson 1964
Hendy et al. 2008
T. variegata is western Atlantic species
Bivalvia - Arcida - Glycymerididae
Glycymeris sp. Da Costa 1778
Bivalvia - Arcida - Arcidae
Arca aff. devincta Conrad 1849
recombined as Anadara (Anadara) devincta
Bivalvia - Pectinida - Pectinidae
Pecten aff. keepi Arnold 1906
recombined as Euvola keepi
Bivalvia - Mytilida - Mytilidae
Mytilus sp. Linnaeus 1758
Bivalvia - Lucinida - Lucinidae
? Phacoides sp. Blainville 1825
Bivalvia - Cardiida - Cardiidae
Cardium sp. Linnaeus 1758
Bivalvia - Cardiida - Veneridae
Chione cf. securis (Shumard 1858)
recombined as Securella securis
Chione temblorensis (Anderson 1905)
recombined as Chione (Chionopsis) temblorensis
Thecostraca - Balanomorpha - Balanidae
Balanus concavus Bronn 1831
recombined as Concavus concavus
Mammalia - Sirenia - Sirenia
Sirenia indet. Illiger 1811
Domning 1978
Echinoidea
Echinoidea indet. (Leske 1778)
see common names

Geography
Country:Mexico State/province:Baja California Sur County:San Lorenzo
Coordinates: 27.2° North, 113.3° West (view map)
Paleocoordinates:26.4° North, 107.9° West
Basis of coordinate:based on nearby landmark
Geographic resolution:outcrop
Time
Period:Neogene Epoch:Miocene
10 m.y. bin:Cenozoic 5
Key time interval:Early/Lower Miocene - Middle Miocene
Age range of interval:23.03000 - 11.63000 m.y. ago
Stratigraphy
Formation:Ysidro Member:Lower
Stratigraphic resolution:bed
Stratigraphy comments: 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.
Lithology and environment
Primary lithology:white lithified sandstone
Includes fossils?Y
Lithology description: Dirty white sandstone.
Environment:coastal indet.
Geology comments: Shallow marine assemblage. No specific paleoenvironmental data presented.
Taphonomy
Modes of preservation:body,mold/impression
Size of fossils:macrofossils
Collection methods and comments
Collection methods:selective quarrying,field collection
Reason for describing collection:biostratigraphic analysis
Collection method comments: Collection studied and determined by J. Smith (Stanford). No known repository.
Taxonomic list comments:Representative.
Metadata
Also known as:Loc. 22
Database number:43804
Authorizer:A. Hendy, M. Uhen Enterer:A. Hendy, M. Uhen
Modifier:A. Hendy Research group:marine invertebrate
Created:2004-08-26 09:46:19 Last modified:2013-11-25 13:37:23
Access level:group members Released:2005-08-26 09:46:19
Creative Commons license:CC BY
Reference information

Primary reference:
11515. 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]

Secondary references:

60295% 34240D. P. Domning. 1978. Sirenian evolution in the North Pacific Ocean. University of California Publications in Geological Sciences 118:1-176 [M. Uhen/M. Uhen/M. Uhen]
19909 A. J. W. Hendy, D. P. Buick, K. V. Bulinski, C. A. Ferguson, and A. I. Miller. 2008. Unpublished census data from Atlantic coastal plain and circum-Caribbean Neogene assemblages and taxonomic opinions. [A. Hendy/A. Hendy/A. Hendy]