Agnostida

Sinodiscus changyangensis

Order Agnostida / Suborder Eodiscina / Superfamily Eodiscoidea / Family Calodiscidae

Cambrian, Series 2, Stage 3Hubei

Sinodiscus changyangensis — photo 1 — Photo 1 · Cephalon holotype NIGP 37358, Ontogenetic sequence reconstruction (Dai pygidium 357 (Hubei; Peng Shanchi et al., 2013) 2020) NWUCYZH 20210-20215 (Hubei; Dai et al., 2013)

Sinodiscus changyangensis — photo 2 — Photo 2 · Cephalon holotype NIGP 37358, Ontogenetic sequence reconstruction (Dai pygidium 357 (Hubei; Peng Shanchi et al., 2013) 2020) NWUCYZH 20210-20215 (Hubei; Dai et al., 2013)

Sinodiscus changyangensis — photo 3 — Photo 3 · Cephalon holotype NIGP 37358, Ontogenetic sequence reconstruction (Dai pygidium 357 (Hubei; Peng Shanchi et al., 2013) 2020) NWUCYZH 20210-20215 (Hubei; Dai et al., 2013)

Sinodiscus changyangensis — photo 4 — Photo 4 · Cephalon holotype NIGP 37358, Ontogenetic sequence reconstruction (Dai pygidium 357 (Hubei; Peng Shanchi et al., 2013) 2020) NWUCYZH 20210-20215 (Hubei; Dai et al., 2013)

Classification

Order Agnostida / Suborder Eodiscina / Superfamily Eodiscoidea / Family Calodiscidae

Genus

Sinodiscus Chang in Lu et al., 1974

Genus author

Zhang Wentang

Genus etymology

sin-, Greek, China, Chinese; discus, disc.

Species

S. changyangensis Zhang in Zhou et al., 1977

Species author

Zhang Sengui

Species etymology

Changyang, from Changyang, Hubei.

Age

Cambrian, Series 2, Stage 3

Distribution

Hubei

Synonyms

Sinodiscus similis; Sinodiscus wenganensis; Sinodiscus duchuanensis; Sinodiscus shuangjieshanensis; Sinodiscus trisulcatus; Sinodiscus kunshanensis

Diagnosis

Glabella large, cylindrical, constricted medially, anterior end subacutely rounded; two crossing glabellar furrows; occipital ring much wider than the glabellar base; palpebral lobes and eye ridges stout; anterior border raised as a stout ridge; preglabellar field short and depressed. Thorax of three segments, axis broad, pleural region widening gradually backward. Pygidial axis divided into four axial rings and a terminal segment, not reaching the posterior border; border distinct.