• Eocene of United States (5: Colorado, Utah, Wyoming collections)

• Clarkforkian of United States (2: Wyoming)

• Paleocene of Belgium (1), Canada (1: Alberta), United States (25: California, Colorado, Montana, North Dakota, Wyoming)

• Cretaceous of Canada (50: Alberta, Saskatchewan), Mexico (4), United States (120: Colorado, Montana, Nevada, New Mexico, North Dakota, South Dakota, Texas, Utah, Wyoming)

• Jurassic of United States (7: Wyoming)

Total: 215 collections including 223 occurrences