Trilobita - Olenida - Olenidae
Synonym: Triarthrinae Ulrich 1930
Parent taxon: Olenidae according to A. W. Owen 1981
See also Fortey 1974, Harrington and Leanza 1957, Ludvigsen 1982, Nikolaisen 1965 and Robison and Pantoja-Alor 1968
Sister taxa: Acerocare, Acerocarina, Aciculolenus, Angelina, Apoplanias, Asilluchus, Baikonuraspis, Balnibarbiinae, Bondarevites, Chekiangaspis, Ctenopyge, Cyclognathina, Euonchonotina, Eurycare, Hancrania, Helieranella, Highgatella, Huangshiaspis, Hypermecaspidinae, Inkouia, Jujuyaspis, Leiobienvillia, Leptobenthos, Leptoplastinae, Leptoplastus, Lisania, Magnomma, Marjumia, Nericiaspis, Olenus, Parabolina, Parabolinella, Parabolinina, Parabolinites, Paraolenus, Paraplicatolina, Peltocare, Peltura, Pelturina, Pelturinae, Plicatolininae, Prohedinella, Protopeltura, Remizites, Rhodonaspis, Saltaspis, Sphaerophthalmella, Talbotinella, Ullaspis, Westergaardia, Westergaardites, Wujiajiania
Subtaxa: Bienvillia Plesioparabolina Porterfieldia Rampartaspis Triarthrus
Ecology: fast-moving low-level epifaunal carnivore
Distribution:
• Uhaku of Norway (1 collection), Sweden (2)
• Chazyan of Canada (3: Newfoundland and Labrador, Northwest Territories)
• Whiterockian of Canada (12: Newfoundland and Labrador), Norway (4)
• Billingen of Norway (1)
• Arenigian of Argentina (30)
• Arenig of Argentina (8), Bolivia (1), China (1), Norway (3), Sweden (1), the United Kingdom (4), United States (1: Nevada)
• Ordovician of Argentina (70), Australia (1), Bolivia (4), Canada (24: Alberta, Newfoundland, Newfoundland and Labrador, Northwest Territories, Nunavut, Ontario, Quebec), China (7), France (2), Ireland (1), Mexico (3), New Zealand (1), Norway (8), Peru (1), the Russian Federation (1), Sweden (8), the United Kingdom (12), United States (50: Kentucky, Michigan, Nevada, New York, Ohio, Pennsylvania), Venezuela (1)
• Ibexian of Norway (3)
• Cambrian to Ordovician of Argentina (1)
• Cambrian of Argentina (3), Canada (9: Newfoundland and Labrador, Quebec), United States (3: Nevada)
Total: 285 collections including 304 occurrences