Corynexochida

Protoryctocephalus wuxunensis

Order Corynexochida / Suborder Corynexochina / Family Oryctocephalidae / Family Oryctocephalinae

Cambrian, Series 2, Stage 4Guizhou

Protoryctocephalus wuxunensis — photo 1 — Photo 1 · Holotype NIGP21482a (Guizhou; left: Yuan Jinliang et al., 2002; right: Peng Shanchi 2020) (Guizhou; left: Yuan Jinliang et al., 2002; right: Peng Shanchi 2020)

Protoryctocephalus wuxunensis — photo 2 — Photo 2 · Holotype NIGP21482a (Guizhou; left: Yuan Jinliang et al., 2002; right: Peng Shanchi 2020) (Guizhou; left: Yuan Jinliang et al., 2002; right: Peng Shanchi 2020)

Classification

Order Corynexochida / Suborder Corynexochina / Family Oryctocephalidae / Family Oryctocephalinae

Genus

Protoryctocephalus Chow in Lu et al., 1974

Genus author

Zhou Zhiyi

Genus etymology

prot-, originally、original;Oryctocephalus, trilobitegenus name, oryctocephalus

Species

P. wuxunensis Chow in Lu et al., 1974

Species author

Zhou Zhiyi

Species etymology

Wuxun, the type specimen is from the upper part of the Wuxun Formation (now the Qingxudong Formation) at Nangao, Kaili, Guizhou

Age

Cambrian, Series 2, Stage 4

Distribution

Guizhou

Diagnosis

Glabella inverted pear-shaped, moderately convex, widest at the middle of the frontal lobe, anterior end rounded, with four pairs of pit-like glabellar furrows, none connected to the dorsal furrow, only S1 with a very weak transverse furrow; Palpebral lobe relatively long, situated in the middle to posterior part of the cranidium, eye ridge strong; palpebral area of the fixed cheek of moderate width; opisthoparian sutures; free cheek narrow, genal spine slender and of moderate length. Thorax of 11 segments; axis and pleural regions nearly equal in width; pleural furrows oblique, pleural spines short. Pygidium small, subtransversely elliptical; axis of 2 rings and 1 terminal piece; pleurae with two pairs of pleural spines and one median spine.