Phacopida

Coronocephalus dentatus

Order Phacopida / Suborder Cheirurina / Superfamily Cheiruroidea / Family Encrinuridae / Subfamily Coronocephalinae

Telychian (Llandovery, Silurian)Hunan

Coronocephalus dentatus — photo 1 — Photo 1 · Type specimen figures (about 6.5 cm; Hunan; left: whitened figure, Zhang 1983; right: colour figure, Yang Qun 2017)

Coronocephalus dentatus — photo 2 — Photo 2 · Type specimen figures (about 6.5 cm; Hunan; left: whitened figure, Zhang 1983; right: colour figure, Yang Qun 2017)

Classification

Order Phacopida / Suborder Cheirurina / Superfamily Cheiruroidea / Family Encrinuridae / Subfamily Coronocephalinae

Genus

Coronocephalus Grabau, 1924

Genus author

Grabau A. W.

Genus etymology

coron (Latin, crown) + cephal- (Greek, head), referring to the crown-like border of the librigenae

Species

C. dentatus Zhang, 1974

Species author

Zhang Wentang

Species etymology

dentatus, Latin, toothed, referring to the row of tooth-like spines on the outer margin of the librigenae

Age

Telychian (Llandovery, Silurian)

Distribution

Hunan

Diagnosis

Dorsal shield narrow and long. Anterior glabellar lobe inflated, sparsely nodose or smooth anteriorly and densely nodose posteriorly; 3 pairs of transglabellar furrows which, together with the occipital furrow, have 4 pairs of large deep pits at their ends; outer margin of the librigenae with a row of 9 tooth-like spines. Thorax of 11 segments; pleurae with distinct, curved pleural furrows. Pygidium triangular; more than 35 axial rings and 15 pairs of pleural segments.

Remarks

The curved shape and position of the thoracic pleural furrows are the most obvious features distinguishing Coronocephalus dentatus from other species.