Pterotheca
Distribution:
• Eocene of the Russian Federation (1 collection)
• Paleocene of Antarctica (17)
• Cretaceous of Antarctica (13), Canada (49: Northwest Territories, Nunavut)
• Silurian of the Czech Republic (1), Spain (1), the United Kingdom (9)
• Ordovician of Canada (16: Ontario, Quebec), the Czech Republic (1), Estonia (2), the United Kingdom (6), United States (19: Illinois, Illinois, Iowa, Indiana, Kentucky, Minnesota, Missouri, New York, Ohio, Tennessee)
Total: 135 collections including 278 occurrences