Heteractinida
Distribution:
• Devonian of Australia (1 collection)
• Silurian of Canada (1: Nunavut), United States (2: Wisconsin)
• Arenigian of Argentina (1)
• Tremadoc of China (1), United States (1: Nevada)
• Cambrian of Antarctica (1), Germany (1), the Russian Federation (2)
Total: 11 collections each including a single occurrence