Rancho Orégano, 4.9 km from [Del Rio Clay] (Cretaceous of Mexico)

Where: Coahuila de Zaragoza, Mexico (29.0° N, 101.0° W: paleocoordinates 28.4° N, 66.7° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Del Rio Clay Formation, Early/Lower Cenomanian (99.6 - 93.5 Ma)

• STRATIGRAPHIC RELATIONS: From the Del Rio Clay, for which lithostratigraphic relations are not clearly stated. AGE: Late Albain; on the basis of ammonite biostratigraphy; Stoliczkaia dispar zone; ID of Stoliczkaia dispar is incorrect; actually Early Cenomanian. STRATIGRAPHIC POSITION: From the Del Rio Clay.

• bed-level stratigraphic resolution

Environment/lithology: marine; lithified, black, gray, blue marl

• SPECIFIC LITHOLOGY: Gray blue, almost blackish marl. LITHIFICATION: Lithified, on the basis of figured specimens.

Size class: macrofossils

Preservation: mold/impression

Collected by Bose; reposited in the UCMP

Collection methods: surface (in situ),

• COLLECTOR: Not stated, but presumably E. Böse. REPOSITORY: University of California, Berkeley.

Primary reference: E. Böse. 1928. Cretaceous ammonites from Texas and northern Mexico. University of Texas Bulletin 2748:143-357 [A. Hendy/A. Hendy/P. Wagner]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 88218: authorized by Austin Hendy, entered by Austin Hendy on 04.04.2009, edited by Matthew Clapham

Creative Commons license: CC BY (attribution)

Taxonomic list

• COVERAGE: Probably not exhaustive, but comprehensive for ammonoids. NOMENCLATURE: Authoritative publication with somewhat antiquated nomenclature, but with species-resolution identifications.
Cephalopoda
 Ammonitida - Acanthoceratidae
"Mantelliceras brazoense" = Graysonites wacoense
"Mantelliceras brazoense" = Graysonites wacoense Böse 1928 ammonite
 Ammonitida - Lyelliceratidae
Stoliczkaia (Lamnayella) texana2 Cragin 1893 ammonite
 Ammonitida - Engonoceratidae
"Engonoceras bravoense" = Metengonoceras bravoense
"Engonoceras bravoense" = Metengonoceras bravoense Böse 1928 ammonite
 Ammonitida - Turrilitidae
"Turrilites brazoensis" = Mariella (Plesioturrilites) brazoensis
"Turrilites brazoensis" = Mariella (Plesioturrilites) brazoensis Roemer 1849 ammonite
Bivalvia
 Ostreida - Gryphaeidae
Gryphaea mucronata1 Gabb 1869 oyster
 Pectinida - Limidae
Lima wacoensis1 Roemer 1849 file clam
 Pectinida - Pectinoidae
"Vola subalpina" = Pecten (Vola)1
"Vola subalpina" = Pecten (Vola)1 scallop
Echinoidea
 Spatangoida - Hemiasteridae
Hemiaster calvini1 Clark 1893 heart urchin
 Euechinoidea - Hemicidaridae
Leptarbacia argutus1 Clark and Twitchell 1915 sea urchin
 Calycina - Phymosomatidae