Trilobita - Trinucleida - Dionididae
Parent taxon: Trinucleida according to A. Bignon et al. 2020
See also Adrain 2011, Jell and Adrain 2002 and Whittington et al. 1997
Sister taxa: Alsataspididae, Liostracinidae, Raphiophoridae, Trinucleidae
Subtaxa: Aethedionide Digrypos Dionide Dionidella Tongxinaspis Trinucleoides
Ecology: fast-moving low-level epifaunal carnivore
Distribution:
• Dobrotivian of the Czech Republic (2 collections), France (3), Portugal (1)
• Arenig of the United Kingdom (3)
• Ordovician of Canada (1: Quebec), China (27), the Czech Republic (7), France (4), Ireland (1), Kazakhstan (3), Morocco (3), Norway (11), the Russian Federation (1), Sweden (4), Turkey (1), the United Kingdom (10), United States (7: Maine, Virginia)
Total: 89 collections including 96 occurrences