Trilobita - Trinucleida - Trinucleidae
Parent taxon: Trinucleidae according to A. W. Owen 1980
See also Ghobadi Pour et al. 2011
Sister taxa: Anebolithus, Auritolithus, Bergamia, Bettonolithus, Botrioides, Costonia, Cryptolithinae, Cryptolithoides, Cryptolithus, Deanaspis, Decordinaspis, Eirelithus, Famatinolithus, Furcalithus, Guandacolithus, Gymnostomix, Hanchungolithinae, Hanchungolithus, Incaia, Jianxilithus, Lloydolithus, Lordshillia, Marekolithus, Marrolithinae, Marrolithoides, Marrolithus, Microdiscus, Myinda, Myindella, Myttonia, Nankinolithus, Ningkianolithus, Novaspis, Onnia, Paratretaspis, Paratrinucleus, Parkesolithus, Protolloydolithus, Reedolithus, Reuscholithus, Salterolithus, Stapeleyella, Telaeomarrolithus, Tretaspidinae, Trinucleus, Whittardolithus, Xiushuilithus, Yinpanolithus
Subtaxa: Iputaspis Kimakaspis Tretaspis
Ecology: fast-moving low-level epifaunal suspension feeder
Distribution:
• Ordovician to Silurian of Canada (2: Québec collections)
• Ordovician of Belgium (4), Canada (10: Quebec), the Czech Republic (4), Ireland (16), Kazakhstan (3), Lithuania (1), Norway (64), the Russian Federation (2), Sweden (14), the United Kingdom (60), United States (8: Maine, Virginia)
Total: 188 collections including 205 occurrences