Potrerillos Formation, Mexico

Potrerillos Formation
Stratigraphic range: Maastrichtian-Early Paleocene ~
Type	Formation
Unit of	Difunta Group
Sub-units	Upper Mudstone member
Lithology
Primary	Mudstone
Other	Grainstone
Location
Coordinates	26°00′N 100°48′W / 26.0°N 100.8°W / 26.0; -100.8
Approximate paleocoordinates	31°42′N 82°42′W / 31.7°N 82.7°W / 31.7; -82.7
Region	Coahuila
Country	Mexico
Potrerillos Formation, Mexico (Mexico)

The Potrerillos Formation is a geologic formation in Mexico. It preserves fossils dating back to the Early Paleocene period.^[1]

The Potrerillos Formation was subdivided into five members by McBride (1974), with the second highest, the Upper Mudstone Member. Foraminifera in the lower members indicate a Maastrichtian age, while fossils in the upper members indicate a Paleocene age. Fossil remains are abundant and include transported remains of corals, gastropods, bivalves, shark teeth, and bone fragments.^[1]

The following fossils have been reported from the formation:^[1]

• Bivalves
  • Venericardia (Baluchicardia) francescae^[2]
  • Venericardia sp.^[2]
• Cephalopods
  • Cimomia haltomi^[2]
  • Elimia cf. trigemmata^[2]

• List of fossiliferous stratigraphic units in Mexico

• Vega, F.J.; Perrilliat, M.D.C. (1995), "On some Paleocene invertebrates from the Potrerillos Formation (Difunta Group), northeastern Mexico", Journal of Paleontology, 69 (5): 863–869, Bibcode:1995JPal...69..862V, doi:10.1017/S0022336000035538