Arroyo Las Paredes, LP 2, San Lucas Formation, Michoacan (Cretaceous of Mexico)

Where: Mexico (18.6° N, 100.8° W)

• Paleocoordinates: 19.9° N, 44.0° W (Wright 2013)

• coordinate stated in text

• small collection-level geographic resolution

When: Terrero Prieto Member (San Lucas Formation), Early/Lower Barremian (130.0 - 125.5 Ma)

• early Early Barremian; lower part: Taveraidiscus hugii auctorum zone, upper part: Nicklesia pulchella zone; Arroyo Las Paredes Section is a 11.5 m thick unit

• bed-level stratigraphic resolution

Environment/lithology: submarine fan; lithified sandstone

• a distinct shallow marine shelf within a tectonically active area, oxygen-deficient bottom waters
• well-bedded dark gray to yelloish volcanic sandstones, with scattered radiolarian-type siliceous bioclasts. Flysch deposit

Size class: macrofossils

Collection methods: quarrying,

Primary reference: R. Barragan, C. Gonzalez-Arreola, and A. B. Villasenor. 2004. Palaeoecological significance of Barremian ammonite assemblages and facies variations from Southwest Mexico. Lethaia 37:223-234 [W. Kiessling/U. Merkel]more details

Purpose of describing collection: paleoecologic analysis

PaleoDB collection 60777: authorized by Wolfgang Kiessling, entered by Uta Merkel on 23.05.2006

Creative Commons license: CC0 (CC0)

Taxonomic list

• proliferation of middle-water depth ammonites
Show authors, comments, and common names
Cephalopoda
 Ammonoidea - Hamulinidae
Hamulina sp.
Hamulina sp. d'Orbigny 1850 ammonite
 Ammonitida - Leptoceratoididae
Karsteniceras sp.
Karsteniceras sp. Royo-Gomez 1945 ammonite
 Ammonitida - Pulchelliidae
Nicklesia sp., Subpulchellia sp.
Nicklesia sp. Hyatt 1903 ammonite