Sierra del Alamo Section, Unit 19 (Jurassic of Mexico)

Where: Sonora, Mexico (30.7° N, 112.6° W: paleocoordinates 18.4° N, 55.0° W)

• coordinate estimated from map

• outcrop-level geographic resolution

When: Lower Member (Sierra de Santa Rosa Formation), Late/Upper Sinemurian (196.5 - 189.6 Ma)

• Sequence XII.

• group of beds-level stratigraphic resolution

Environment/lithology: open shallow subtidal; lithified, gray sandstone and lithified, sandy grainstone

Size class: macrofossils

Preservation: cast, mold/impression, coquina

Collection methods: bulk, surface (float),

Primary reference: A. Scholz, M. Aberhan, and C.M. León. 2008. Early Jurassic bivalves of the Antimonio terrane (Sonora, NW Mexico): Taxonomy, biogeography, and paleogeographic implications. Geological Society of America Special Paper 442:269-312 [A. Miller/S. Kolbe/P. Wagner]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 115212: authorized by Arnold Miller, entered by Sarah Kolbe on 31.08.2011

Creative Commons license: CC BY (attribution)

Taxonomic list

 Pectinida - Neitheoidae
Weyla alata von Buch 1838 scallop
Weyla unca Philippi 1899 scallop
 Carditida - Astartidae
Neocrassina gueuxi d'Orbigny 1850 clam
 Cardiida - Cardiidae
Protocardia luggudensis Troedsson 1951 cockle