Trilobita - Ptychopariida - Acrocephalitidae
Parent taxon: Ptychopariida according to H. B. Whittington et al. 1997
See also Adrain 2011
Sister taxa: Alokistocaridae, Amphorella, Atratebiinae, Bifodina, Bolaspididae, Bulnibarbi, Bvalbardites, Catillicephalidae, Chondrastaulina, Chuangiformis, Cliffiidae, Conococheaquea, Conocoryphidae, Conokephalinidae, Crepicephalidae, Diceratocephalidae, Elviniidae, Harpina, Indiligens, Kazelina, Kingstoniidae, Kirengelia, Lisaniidae, Lonchocephalidae, Lorenzellidae, Marjumiidae, Meniscocorphye, Meniscocoryphe, Menomoniidae, Neoanomocerella, Norwoodiidae, Olenina, Papyriaspididae, Phylacteridae, Plethopeltidae, Proasaphiscidae, Propeltura, Ptychopariidae, Ptychopariina, Ptychoparoides, Raymondinidae, Shumardiidae, Solenopleuracea, Solenopleuridae, Tricrepicephalidae, Xianquianaspis, Yuehsieszella
Subtaxa: Acrocephalella Acrocephalites Acrodirotes Asturiaspis Brutaspis Cermataspis Decus Diceratocephalina Ijacephalus Mansiella Pseudacrocephalaspina
Ecology: fast-moving low-level epifaunal carnivore
Distribution:
• Ordovician of the Russian Federation (4 collections)
• Tremadoc of the Russian Federation (3)
• Cambrian to Ordovician of the Russian Federation (1)
• Cambrian of Australia (2), Denmark (1), Kazakhstan (6), the Russian Federation (7), Turkey (1)
• Taoyuanian of the Russian Federation (4)
• Delamaran of United States (1: California)
Total: 30 collections including 35 occurrences