Rancho Bufalo section [Tuape Shale Mbr, Mural Fm] (Cretaceous of Mexico)

Where: Sonora, Mexico (30.9° N, 109.5° W: paleocoordinates 31.3° N, 64.2° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Tuape Shale Member (Mural Formation), Late/Upper Aptian (122.5 - 113.0 Ma)

• STRATIGRAPHIC RELATIONS: From the Tuape Shale of the Mural Fm, which gradationally overlies the Cerro La Ceja, and is overlain by the Los Coyotes Mbr AGE: Aptian, on the basis of ammonite, bivalve, and foram biostratigraphy, and U/Pb zircon radiometric ages. STRATIGRAPHIC POSITION: List representative of entire member at this section.

• member-level stratigraphic resolution

Environment/lithology: offshore; poorly lithified, concretionary, black, brown, gray, green shale and poorly lithified siltstone

• ENVIRONMENT: Shallow marine siliciclastic, accumulated during maximum flooding phase.
• SPECIFIC LITHOLOGY: Various lithologies, including dark gray to black, locally laminated shale that weathers yellowish brown and dark gray to green with calcareous nodules and interbeds of laminated siltstone and shaly limestone beds. LITHIFICATION: Poorly lithified on the basis of figured specimens.

Size class: macrofossils

Collection methods: COLLECTORS: Multiple collectors, principally, T. F. Lawton, and R. W. Scott. REPOSITORY: ERNO, Instituto de Geologia, Universidad Nacional Autónoma de México, Sonora, Mexico.

Primary reference: C. M. González-Léon, R. W. Scott, H. Löser, T. F. Lawton, E. Robert and V.A. Valencia. 2008. Upper Aptian-Lower Albian Mural Formation: stratigraphy, biostratigraphy and depositional cycles on the Sonoran shelf, northern Mexico. Cretaceous Research 29:249-266 [A. Hendy/A. Hendy]more details

Purpose of describing collection: paleoecologic analysis

PaleoDB collection 82142: authorized by Austin Hendy, entered by Austin Hendy on 23.07.2008

Creative Commons license: CC BY (attribution)

Taxonomic list

• COVERAGE: Limited to biostratigraphically or paleoecologically important taxa and those informally mentioned in text. NOMENCLATURE: Not an authoritative publication, but with fairly modern nomenclature, but unfortunately lacking some species-level identifications.
Show authors, comments, and common names
Cephalopoda
 Ammonitida - Acanthohoplitidae
Immunitoceras immunitum
Immunitoceras immunitum Stoyanow 1949 ammonite
 Ammonitida - Parahoplitidae
Quitmanites sp., Quitmanites ceratitosus
Quitmanites sp. Scott 1940 ammonite
Quitmanites ceratitosus Scott 1940 ammonite
Bivalvia
 Trigoniida - Trigoniidae
Buchotrigonia reesidei