Trilobite Zonation - Laurentia
15International timescale
Ordovician
Early Ordovician
Tremadocian
Cambrian
Furongian
Stage 10
Jiangshanian
Paibian
Miaolingian
Guzhangian
Drumian
Wuliuan
Series 2
Stage 4
Stage 3
Terreneuvian
Stage 2
Trilobite Zonation - Laurentia
Symphysurina bulbosa
Symphysurina brevispicata
Missisquoia
Eurekia apopsis
Saukiella serotina
Saukiella junia/Saukiella pyrene
Ellipsocephaloides-Idahoia
Taenicephalus
Elvinia
Dunderbergia
Aphelaspis
Crepicephalus
Cedaria
Bolaspidella
Ptychagnostus gibbus
Ptychagnostus praecurrens
Albertella
Plagiura-Poliella
Amecephalus arrojosensis
Eokochaspis nodosa
Olenellus
Nevadella
Fallotaspis
Fritzaspis
Wyattia
Zone
Symphysurina bulbosaSymphysurina brevispicataMissisquoiaEurekia apopsisSaukiella serotinaSaukiella junia/Saukiella pyreneEllipsocephaloides-IdahoiaTaenicephalusElviniaDunderbergiaAphelaspisCrepicephalusCedariaBolaspidellaPtychagnostus gibbusPtychagnostus praecurrensAlbertellaPlagiura-PoliellaAmecephalus arrojosensisEokochaspis nodosaOlenellusNevadellaFallotaspisFritzaspisWyattia
