Trilobita - Ptychopariida - Olenidae

Alternative combination: Triarthrus thor

Full reference: R. A. Fortey. 1974. The Ordovician trilobites of Spitsbergen. I. Olenidae. Norsk Polarinstitutt Skrifter 160:1-129

Belongs to Porterfieldia according to R. Ludvigsen and P. A. Tuffnell 1983

Sister taxa: Porterfieldia caecigenus, Porterfieldia convergens, Porterfieldia fisheri, Porterfieldia jachalensis, Porterfieldia parapunctata, Porterfieldia sinensis

Type specimen: SMA 84109, a cephalon/head (cranidium)

Ecology: fast-moving low-level epifaunal carnivore