Buthrotrephis
Distribution:
• Devonian of the Czech Republic (1 collection), United States (1: Alaska)
• Silurian of United States (1: Maryland)
Total: 3 collections each including a single occurrence
Distribution:
• Devonian of the Czech Republic (1 collection), United States (1: Alaska)
• Silurian of United States (1: Maryland)
Total: 3 collections each including a single occurrence