Agnostida

Ptychagnostus aculeatus

Order Agnostida / Suborder Agnostina / Superfamily Agnostoidea / Family Ptychagnostidae

Cambrian, Miaolingian, GuzhangianZhejiang, Hunan, Xinjiang; Central Asia, Europe, North America, South America
Ptychagnostus aculeatus — photo 1
Photo 1 · Type KUMIP 204203, 204204, 204208, 204209 WIHGF1008.2, 817 specimen s (USA; Robison 1984) (India; Peng et al., 2009) (cephalon is the lectotype; Sweden; Westergård 1946) Complete dorsal shield (Hunan; Peng Shanchi 2020) (1.3 cm; Xinjiang; Amazon) 0.7cm、1.5cm (Zhejiang; strongZJU)
Ptychagnostus aculeatus — photo 2
Photo 2 · Type KUMIP 204203, 204204, 204208, 204209 WIHGF1008.2, 817 specimen s (USA; Robison 1984) (India; Peng et al., 2009) (cephalon is the lectotype; Sweden; Westergård 1946) Complete dorsal shield (Hunan; Peng Shanchi 2020) (1.3 cm; Xinjiang; Amazon) 0.7cm、1.5cm (Zhejiang; strongZJU)
Ptychagnostus aculeatus — photo 3
Photo 3 · Type KUMIP 204203, 204204, 204208, 204209 WIHGF1008.2, 817 specimen s (USA; Robison 1984) (India; Peng et al., 2009) (cephalon is the lectotype; Sweden; Westergård 1946) Complete dorsal shield (Hunan; Peng Shanchi 2020) (1.3 cm; Xinjiang; Amazon) 0.7cm、1.5cm (Zhejiang; strongZJU)
Ptychagnostus aculeatus — photo 4
Photo 4 · Type KUMIP 204203, 204204, 204208, 204209 WIHGF1008.2, 817 specimen s (USA; Robison 1984) (India; Peng et al., 2009) (cephalon is the lectotype; Sweden; Westergård 1946) Complete dorsal shield (Hunan; Peng Shanchi 2020) (1.3 cm; Xinjiang; Amazon) 0.7cm、1.5cm (Zhejiang; strongZJU)
Ptychagnostus aculeatus — photo 5
Photo 5 · Type KUMIP 204203, 204204, 204208, 204209 WIHGF1008.2, 817 specimen s (USA; Robison 1984) (India; Peng et al., 2009) (cephalon is the lectotype; Sweden; Westergård 1946) Complete dorsal shield (Hunan; Peng Shanchi 2020) (1.3 cm; Xinjiang; Amazon) 0.7cm、1.5cm (Zhejiang; strongZJU)
Ptychagnostus aculeatus — photo 6
Photo 6 · Type KUMIP 204203, 204204, 204208, 204209 WIHGF1008.2, 817 specimen s (USA; Robison 1984) (India; Peng et al., 2009) (cephalon is the lectotype; Sweden; Westergård 1946) Complete dorsal shield (Hunan; Peng Shanchi 2020) (1.3 cm; Xinjiang; Amazon) 0.7cm、1.5cm (Zhejiang; strongZJU)
Ptychagnostus aculeatus — photo 7
Photo 7 · Type KUMIP 204203, 204204, 204208, 204209 WIHGF1008.2, 817 specimen s (USA; Robison 1984) (India; Peng et al., 2009) (cephalon is the lectotype; Sweden; Westergård 1946) Complete dorsal shield (Hunan; Peng Shanchi 2020) (1.3 cm; Xinjiang; Amazon) 0.7cm、1.5cm (Zhejiang; strongZJU)
Classification
Order Agnostida / Suborder Agnostina / Superfamily Agnostoidea / Family Ptychagnostidae
Genus
Ptychagnostus Jaekel, 1909
Genus author
Jaekel O.
Genus etymology
ptych-, Greek, fold; Agnostus, a trilobite genus name.
Species
P. aculeatus (Angelin, 1851)
Species author
Angelin N. P.
Species etymology
aculeatus, spined, spiny.
Age
Cambrian, Miaolingian, Guzhangian
Distribution
Zhejiang, Hunan, Xinjiang; Central Asia, Europe, North America, South America
Synonyms
Agnostus aculeatus; Goniagnostus aculeatus; Huarpagnostus costatus; Canotagnostus huarpeanus; Huarpagnostus huarpeanus; Ptychagnostus (Ptychagnostus) aculeatus; Acidusus aculeatus; Goniagnostus (Alloboduchus) aculeatus
Diagnosis
Cephalon and pygidium densely covered with stout, dense nodose ornament. Cephalon subsquare, cheek with radiating furrows; preglabellar median furrow distinct; glabellar frontal lobe elongate-conical; posterior lobe transversely tripartite, median part raised club-like; basal lobe small; border and border furrow both narrow; with a pair of long posterolateral spines. Pygidium subsquare; pygidial axis long-conical; pygidial border broad, border furrow shallow; no posterolateral spines.
Remarks
Individuals generally large, up to about 2 cm.