Cannonball Hill (Cretaceous of Mexico)

Where: Chihuahua, Mexico (30.8° N, 105.2° W: paleocoordinates 33.1° N, 72.9° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Ojinaga Formation, Middle Turonian (93.5 - 89.3 Ma)

• 450 m above the base of the Ojinaga Formation, Collignoniceras woollgari zone, woollgari woollgari subzone

• group of beds-level stratigraphic resolution

Environment/lithology: marine; lithified limestone

• septarian concretions

Size class: macrofossils

Preservation: mold/impression

Reposited in the OUM

• '... observations are based on collections in the U.s. Geological survey at the Federal Center, Denver, Colorado, as well as material noted by King & Adkins (1946) and Powell (1963) plus additional material collected by Professor J. M. Hancock and ourselves from Powell's Cannonball Hill locality...'

Primary reference: W. J. Kennedy and W. A. Cobban. 1988. Mid-Turonian ammonite faunas from northern Mexico. Geological Magazine 125(6):593-612 [M. Aberhan/S. Nurnberg/S. Nurnberg]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 38965: authorized by Martin Aberhan, entered by Sabine N├╝rnberg on 18.05.2004, edited by Uta Merkel

Creative Commons license: CC BY (attribution)

Taxonomic list

• Focus on ammonites.
Bivalvia
 Myalinida - Inoceramidae
Cephalopoda
 Ammonitida - Collignoniceratidae
Collignoniceras woollgari Mantell 1822 ammonite
ssp. woollgari
Selwynoceras mexicanum Bose 1927 ammonite
 Ammonitida - Vascoceratidae
"Neoptychites cephalotus" = Neoptychites cephalotus, "Neoptychites xetriformis" = Neoptychites cephalotus, "Neoptychites gourguechoni" = Neoptychites cephalotus
"Neoptychites cephalotus" = Neoptychites cephalotus Courtiller 1860 ammonite
"Neoptychites xetriformis" = Neoptychites cephalotus Courtiller 1860 ammonite
"Neoptychites gourguechoni" = Neoptychites cephalotus Courtiller 1860 ammonite
 Ammonitida - Acanthoceratidae
Spathites rioensis n. sp. Powell 1963 ammonite
Morrowites sp. Cobban and Hook 1983 ammonite
"Mammites depressus n. sp." = Morrowites depressus Powell 1963 ammonite
Kamerunoceras isovokyense Collignon 1965 ammonite
 Ammonitida - Coilopoceratidae
Hoplitoides ingens Koenen 1898 ammonite
Coilopoceras sp. Hyatt 1903 ammonite
 Ammonitida - Baculitidae
Baculites yokoyamai Tokunga and Shimizu 1926 ammonite