• Silurian of United States (3: Iowa, New York collections)

• Dobrotivian of Spain (1)

• Letna of the Czech Republic (1)

• Arenig of United States (3: Nevada)

• Arenigian of United States (2: Nevada, Utah)

• Ordovician of Canada (1: Ontario), China (1), the Czech Republic (3), Spain (3), the United Kingdom (1), United States (2: Nevada, Virginia)

Total: 21 collections each including a single occurrence