Olenidae

Olenidae is a family of ptychopariid trilobites. Some genera, Balnibarbi and Cloacaspis, are thought to have evolved a symbiotic relationship with sulfur-eating bacteria from which they derived nutrition.

== Genera == Acerocare Acerocarina Aciculolenus Anaximander Angelina (=Keidelaspis), Apoplanias Asilluchus Baikonuraspis Balnibarbi Bienvillia (=Diatemnus; =Mendoparabolina) Boeckaspis (/Boeckia BROGGER; =Sphaerophthalmella) Bondarevites Bulbolenus Chekiangaspis Cloacaspis Ctenopyge Cyclognathina Danarcus Desmetia Eoctenopyge Euonchonotina Eurycare Granitzia Hancrania Helieranella Highgatella Huangshiaspis Hunanolenus Hypermecaspis (=Spitsbergaspis), Inkouia (=Agalatus), Isidrella Jujuyaspis (=Alimbetaspis), Leiobienvillia Leptoplastides (=Andesaspis;=Beltella; =Chunkingaspis; =Parabolinopsis; *Rampartaspis), Leptoplastus Leurostega Magnomma Mesoctenopyge Moxomia Neoolenus Neoparabolina Nericiaspis Olenus (=Simulolenus), Orkekeia Parabolina (/*Odontopyge), Parabolinella Parabolinina Parabolinites Paraolenus Paraplicatolina Peltocare Peltura (/Anthes; =Anopocare), Pelturina Plicatolina Plicatolinella Porterfieldia Prohedinella Protopeltura Psilocara Remizites Rhodonaspis Saltaspis Shihuigouia Sphaerophthalmus Svalbardites Talbotinella Triarthrus (/*Brongniartia EATON)? Ullaspis Westergaardia (=Sphaerophthalmoides) Westergaardites Wujiajiania.