Agnostida

Hypagnostus brevifrons

Order Agnostida / Suborder Agnostina / Superfamily Agnostoidea / Family Peronopsidae

Cambrian, Miaolingian Drumian to GuzhangianZhejiang, Hunan, Qinghai, Sichuan; Europe

Hypagnostus brevifrons — photo 1 — Photo 1 · Agnostus brevifrons; Metagnostus brevifrons; Cyclopagnostus brevifrons; Hypagnostus kendectasicus; H. aff. Upper-left cephalon is the lectotype (Sweden; Illustrated specimens (Hunan; Peng Westergård 1946) Shanchi 2020) Illustrated specimens (Hunan; Peng et al., Complete dorsal shield (Zhejiang; 2000) StrongZJU)

Hypagnostus brevifrons — photo 2 — Photo 2 · Agnostus brevifrons; Metagnostus brevifrons; Cyclopagnostus brevifrons; Hypagnostus kendectasicus; H. aff. Upper-left cephalon is the lectotype (Sweden; Illustrated specimens (Hunan; Peng Westergård 1946) Shanchi 2020) Illustrated specimens (Hunan; Peng et al., Complete dorsal shield (Zhejiang; 2000) StrongZJU)

Hypagnostus brevifrons — photo 3 — Photo 3 · Agnostus brevifrons; Metagnostus brevifrons; Cyclopagnostus brevifrons; Hypagnostus kendectasicus; H. aff. Upper-left cephalon is the lectotype (Sweden; Illustrated specimens (Hunan; Peng Westergård 1946) Shanchi 2020) Illustrated specimens (Hunan; Peng et al., Complete dorsal shield (Zhejiang; 2000) StrongZJU)

Hypagnostus brevifrons — photo 4 — Photo 4 · Agnostus brevifrons; Metagnostus brevifrons; Cyclopagnostus brevifrons; Hypagnostus kendectasicus; H. aff. Upper-left cephalon is the lectotype (Sweden; Illustrated specimens (Hunan; Peng Westergård 1946) Shanchi 2020) Illustrated specimens (Hunan; Peng et al., Complete dorsal shield (Zhejiang; 2000) StrongZJU)

Classification

Order Agnostida / Suborder Agnostina / Superfamily Agnostoidea / Family Peronopsidae

Genus

Hypagnostus Jaekel, 1909

Genus author

Jaekel O.

Genus etymology

hyp-, deficient, reduced, low, below; Agnostus, a trilobite genus name.

Species

H. brevifrons (Angelin, 1851)

Species author

Angelin N. P.

Species etymology

brevi-, short; frons, forehead, front.

Age

Cambrian, Miaolingian Drumian to Guzhangian

Distribution

Zhejiang, Hunan, Qinghai, Sichuan; Europe

Synonyms

Exsculptus; H. brachydolonus; H. qilianensis H. brevifrons tianshanicus; H. stigmaeus; H. angulus; H.(Breviagnostus)brachyaxonus H.(B.)brachydolonus; H.(Metahypagnostus)brachydolonus; H.(M.)koutianwuensis H. parabrevifrons; Acadagnostus?transversus

Diagnosis

Compared with Hypagnostus parvifrons, the anterior end of the glabella is narrower, the pygidial axis is shorter with subacutely rounded terminal end, and there is no postaxial median furrow (exfoliated specimens show an incomplete postaxial median furrow)

Remarks

Typical body length about 0.2-1 cm.