USGS 13986 - Tamaulipas, Mexico (middle Laredo Formation): Middle Eocene, Mexico

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Gastropoda - Naticidae
Neverita limula (Conrad 1833)
Subspecies: Neverita limula ceryx
Gastropoda - Neogastropoda - Buccinidae
Lacinia santander
Bolis mexicana
Gastropoda - Ampullinidae
Ampullina ? dumblei
Gastropoda - Heterostropha - Architectonicidae
Architectonica alveata (Conrad 1833)
recombined as Architectonica (Stellaxis) alveatum
Bivalvia - Nuculida - Nuculidae
Nucula mauricensis (Harris 1919)
recombined as Nucula (Nucula) mauricensis
Bivalvia - Carditida - Carditidae
Venericardia (Venericor) densata (Conrad 1845)
Bivalvia - Cardiida - Tellinidae
Tellina mooreana Gabb 1860
recombined as Tellina (Eurytellina) mooreana
see common names

Geography
Country:Mexico State/province:Tamaulipas
Coordinates: 26.4° North, 99.2° West (view map)
Paleocoordinates:28.4° North, 89.6° West
Basis of coordinate:based on nearby landmark
Geographic resolution:outcrop
Time
Period:Paleogene Epoch:Eocene
10 m.y. bin:Cenozoic 2-3
Key time interval:Middle Eocene
Age range of interval:47.80000 - 37.71000 m.y. ago
Stratigraphy
Geological group:Claiborne Formation:Laredo Member:Middle
Local section:Mier
Regional section:Nuevo Leon
Stratigraphic resolution:bed
Stratigraphy comments: The succession of Claiborne Group in northeastern Mexico is exceptionally thick and well correlated to those units of the same name in Texas on the basis of faunal similarity. The name Laredo Formation replaces the "Cook Mountain Formation" in the Rio Grande embayment. The Laredo Formation is divided into three members: lower, middle and upper. The collection is from the middle member.
Lithology and environment
Primary lithology:glauconitic,brown,gray calcareous sandstone
Includes fossils?Y
Lithology description: Matrix is characteristically a brownish-gray, calcareous, glauconitic sandstone interbedded in buff sandstone and shale.
Environment:marine indet.
Geology comments: Siliciclastic. No paleoenvironmental data reported.
Taphonomy
Modes of preservation:body
Size of fossils:macrofossils
Collection methods and comments
Collection methods:selective quarrying,field collection
Reason for describing collection:taxonomic analysis
Museum repositories:USNM
Collection method comments: Collections reposited in USGS and USNM collections.
Taxonomic list comments:Exhaustive for mollusca.
Metadata
Also known as:USGS 13986
Database number:42984
Authorizer:A. Hendy Enterer:A. Hendy
Modifier:A. Hendy Research group:marine invertebrate
Created:2004-08-07 21:02:16 Last modified:2013-11-25 13:37:23
Access level:the public Released:2004-08-07 21:02:16
Creative Commons license:CC BY
Reference information

Primary reference:

7474. J. Gardner. 1945. Mollusca of the Tertiary formations of Northeastern Mexico. Geological Society of American Memoir 11 [M. Kosnik/M. Kosnik/M. Kosnik]