Agnostida

Leiagnostus sanduensis

Order Agnostida / Suborder Agnostina / Superfamily Agnostoidea / Family uncertain

Ordovician, Early Ordovician TremadocianGuizhou, Zhejiang, Hunan

Leiagnostus sanduensis — photo 1 — Photo 1 · Holotype SD204 (Guizhou; Zhou Complete dorsal shield (Zhejiang; Lu et Tianrong 1981) al., 1984) Middle figure faintly showing the pygidial axis, right figure compressed and deformed (Hunan; Lixia)

Leiagnostus sanduensis — photo 2 — Photo 2 · Holotype SD204 (Guizhou; Zhou Complete dorsal shield (Zhejiang; Lu et Tianrong 1981) al., 1984) Middle figure faintly showing the pygidial axis, right figure compressed and deformed (Hunan; Lixia)

Leiagnostus sanduensis — photo 3 — Photo 3 · Holotype SD204 (Guizhou; Zhou Complete dorsal shield (Zhejiang; Lu et Tianrong 1981) al., 1984) Middle figure faintly showing the pygidial axis, right figure compressed and deformed (Hunan; Lixia)

Leiagnostus sanduensis — photo 4 — Photo 4 · Holotype SD204 (Guizhou; Zhou Complete dorsal shield (Zhejiang; Lu et Tianrong 1981) al., 1984) Middle figure faintly showing the pygidial axis, right figure compressed and deformed (Hunan; Lixia)

Leiagnostus sanduensis — photo 5 — Photo 5 · Holotype SD204 (Guizhou; Zhou Complete dorsal shield (Zhejiang; Lu et Tianrong 1981) al., 1984) Middle figure faintly showing the pygidial axis, right figure compressed and deformed (Hunan; Lixia)

Classification

Order Agnostida / Suborder Agnostina / Superfamily Agnostoidea / Family uncertain

Genus

Leiagnostus Jaekel, 1909

Genus author

Jaekel O.

Genus etymology

lei-, Greek, smooth; Agnostus, a trilobite genus name.

Species

L. sanduensis Zhou, 1981

Species author

Zhou Tianrong

Species etymology

Sandu, Sandu, Guizhou, the type locality.

Age

Ordovician, Early Ordovician Tremadocian

Distribution

Guizhou, Zhejiang, Hunan

Diagnosis

Cephalon and pygidium smooth, convex, oval. Cephalon rounded, without border; glabella obscure, with a small node medially. Pygidial axis about 1/2 of the pygidium. Pygidium gradually tapering backward; at the anterior margin A stout median node at the anterior third; border furrow broad, widest posteriorly.