Agnostida

Diplagnostus planicauda

Order Agnostida / Suborder Agnostina / Superfamily Agnostoidea / Family Diplagnostidae

Cambrian, Miaolingian, GuzhangianZhejiang, Hunan; Sweden

Diplagnostus planicauda — photo 1 — Photo 1 · Topotype specimens SGU 4870, 4871 (Sweden; Whittington et al., 1997) Illustrated specimens NIGP 123951, 123952, 123954, 123956 (Hunan; Peng Shanchi 2020) Complete dorsal shield of early adult (Zhejiang; Illustrated specimens NIGP 66199, Baishui) 66195, 66202 (Zhejiang; Lu Yanhao et al. 1989)

Diplagnostus planicauda — photo 2 — Photo 2 · Topotype specimens SGU 4870, 4871 (Sweden; Whittington et al., 1997) Illustrated specimens NIGP 123951, 123952, 123954, 123956 (Hunan; Peng Shanchi 2020) Complete dorsal shield of early adult (Zhejiang; Illustrated specimens NIGP 66199, Baishui) 66195, 66202 (Zhejiang; Lu Yanhao et al. 1989)

Diplagnostus planicauda — photo 3 — Photo 3 · Topotype specimens SGU 4870, 4871 (Sweden; Whittington et al., 1997) Illustrated specimens NIGP 123951, 123952, 123954, 123956 (Hunan; Peng Shanchi 2020) Complete dorsal shield of early adult (Zhejiang; Illustrated specimens NIGP 66199, Baishui) 66195, 66202 (Zhejiang; Lu Yanhao et al. 1989)

Diplagnostus planicauda — photo 4 — Photo 4 · Topotype specimens SGU 4870, 4871 (Sweden; Whittington et al., 1997) Illustrated specimens NIGP 123951, 123952, 123954, 123956 (Hunan; Peng Shanchi 2020) Complete dorsal shield of early adult (Zhejiang; Illustrated specimens NIGP 66199, Baishui) 66195, 66202 (Zhejiang; Lu Yanhao et al. 1989)

Diplagnostus planicauda — photo 5 — Photo 5 · Topotype specimens SGU 4870, 4871 (Sweden; Whittington et al., 1997) Illustrated specimens NIGP 123951, 123952, 123954, 123956 (Hunan; Peng Shanchi 2020) Complete dorsal shield of early adult (Zhejiang; Illustrated specimens NIGP 66199, Baishui) 66195, 66202 (Zhejiang; Lu Yanhao et al. 1989)

Classification

Order Agnostida / Suborder Agnostina / Superfamily Agnostoidea / Family Diplagnostidae

Genus

Diplagnostus Jaekel, 1909

Genus author

Jaekel O.

Genus etymology

dipl-, Greek, double; Agnostus, a trilobite genus name.

Species

D. planicauda (Angelin, 1851)

Species author

Angelin N. P.

Species etymology

plan-, Latin, flat; cauda, Latin, tail.

Age

Cambrian, Miaolingian, Guzhangian

Distribution

Zhejiang, Hunan; Sweden

Synonyms

Agnostus planicauda; Diplagnostus jarillensis; D. planicauda var. bilobatus; D. brevicus; D. floralis; D. cf. humilis; D. planicauda vestgothicus; D. zhexiensis; D. qinlingensis; D. planicauda bilobatus

Diagnosis

Glabellar frontal lobe subsquare with distinct anterior pit; posterior lobe with pointed terminal end; preglabellar median furrow shallow or weak; cheek with weak radiating short furrows; border narrow; border furrow of moderate width. Pygidium part of the axis divided into three lobes; median node large; terminal lobe triangular, close to the pre-border ridge of the posterior margin; the two ends of the pre-border ridge not connected to the lateral margins; with a pair of posterolateral spines.

Remarks

This species is the type species of Diplagnostus. Typical body length about 0.2-1.2 cm.