The most primitive of trilobite orders with a small pygidium and a rather flattened body form.
Redlichia
Lower Cambrian,
Sichuan, China
Size: 3 x 1.5cm
Bathynotus kueichonensis Lu
Lower Cambrian, China
Size: 1.5 cm
Arose early from the Redlichiida and gave rise to several other orders before disappearing in the Upper Ordovician.
Kaotaia,
Lower Cambrian,
Guizhou, China
Size: 0.5cm
Danzhaina
Lower Cambrian,
Guizhou, China
Size: 1.5 cm
Uncertain origin but appeared in the Middle Cambrian and was typically spiny. The development of spines may have been a defensive adaptation or as stabilization structures for slow-swimming, or for living on a loose sediment substrate.
Damesella
Middle Cambrian, Shandong, China
Size: 9 x 6cm
Blackwelderia sinensis Bergeron
Upper Cambrian, Shandong, China
Size: 3.5 cm
Drepanura is a trilobite recorded only from China. The pygidium of the genus, with a pair of large spines extending backward and outward, resembles a bat. During the Jin Dynasty the Drepanura-bearing rocks were called “Bianfushi” (meaning literally “stone with bat”) and were used for ancient ink stones.
Drepanura sp.
Upper Cambrian, Shandong, China
Sample Size: 10x7 cm
Order with a typically large pygidium, evolved from the Ptychopariida originating in the Middle Cambrian and extending to the Upper Silurian.
Asaphellus aristous Liu
Lower Ordovician, Yongshan,Hunan, China
Size: 10 cm
Xiangxia
Lower Ordovician, Hunan, China
Size: 14 x 10cm
An early order derived from Redlichiida and persisting to the Upper Devonian.
Annamitella convexa Liu
Lower Ordovician, Hunan, China
Size: 5 cm
Annamitella
Lower Ordovician, Hunan, China
Size: one 6 x 4cm and two 2 x 5 cm species
Latest occurring order with an uncertain origin, arising in the Lower Ordovician and persisting to the end of the Devonian.
Coronocephalus changningensis Chang
Lower Silurian, Shanxi, China
Size: 1-2 cm
Coronocephalus ovatus Chang
Silurian
Hunan, China
Size: 5cm
Coronocephalus
Silurian, Sichuan, China (mold and cast)
Size: 6 x 5.5cm