Asaphida

Hexacopyge yichangensis

Order Asaphida / Superfamily Remopleuridioidea / Family Remopleurididae Genus Hexacopyge Yuan & Zhou, 1998

Sandbian to Katian (Late Ordovician)Hubei, Hunan, Shaanxi, Chongqing, Yunnan

Hexacopyge yichangensis — photo 1 — Photo 1 · this genus, distinguishing it from the two pairs of Remopleurides. Wenwei Hypostome specimen Holotype WIGM OT0038 (Yunnan) Pygidium and hypostome (Hubei; photograph courtesy of (collected by Prof. and Mrs. Zhou Zhiyi; Prof. Zhou Zhiqiang) photograph courtesy of Prof. Zhou specimens (Hunan; Zhiqiang) photograph courtesy of Prof. Zhou Zhiqiang) Enrolled specimen (Yunnan; Enrolled pygidium specimen (Yunnan; Specimen with an axial spine preserved on DUS) Tuyang Tuseng Po) segment 8 (Yunnan; DUS) (Yunnan; Qianli Zhijiang) (Yunnan; Wuxing) (Yunnan; source unknown)

Hexacopyge yichangensis — photo 2 — Photo 2 · this genus, distinguishing it from the two pairs of Remopleurides. Wenwei Hypostome specimen Holotype WIGM OT0038 (Yunnan) Pygidium and hypostome (Hubei; photograph courtesy of (collected by Prof. and Mrs. Zhou Zhiyi; Prof. Zhou Zhiqiang) photograph courtesy of Prof. Zhou specimens (Hunan; Zhiqiang) photograph courtesy of Prof. Zhou Zhiqiang) Enrolled specimen (Yunnan; Enrolled pygidium specimen (Yunnan; Specimen with an axial spine preserved on DUS) Tuyang Tuseng Po) segment 8 (Yunnan; DUS) (Yunnan; Qianli Zhijiang) (Yunnan; Wuxing) (Yunnan; source unknown)

Hexacopyge yichangensis — photo 3 — Photo 3 · this genus, distinguishing it from the two pairs of Remopleurides. Wenwei Hypostome specimen Holotype WIGM OT0038 (Yunnan) Pygidium and hypostome (Hubei; photograph courtesy of (collected by Prof. and Mrs. Zhou Zhiyi; Prof. Zhou Zhiqiang) photograph courtesy of Prof. Zhou specimens (Hunan; Zhiqiang) photograph courtesy of Prof. Zhou Zhiqiang) Enrolled specimen (Yunnan; Enrolled pygidium specimen (Yunnan; Specimen with an axial spine preserved on DUS) Tuyang Tuseng Po) segment 8 (Yunnan; DUS) (Yunnan; Qianli Zhijiang) (Yunnan; Wuxing) (Yunnan; source unknown)

Hexacopyge yichangensis — photo 4 — Photo 4 · this genus, distinguishing it from the two pairs of Remopleurides. Wenwei Hypostome specimen Holotype WIGM OT0038 (Yunnan) Pygidium and hypostome (Hubei; photograph courtesy of (collected by Prof. and Mrs. Zhou Zhiyi; Prof. Zhou Zhiqiang) photograph courtesy of Prof. Zhou specimens (Hunan; Zhiqiang) photograph courtesy of Prof. Zhou Zhiqiang) Enrolled specimen (Yunnan; Enrolled pygidium specimen (Yunnan; Specimen with an axial spine preserved on DUS) Tuyang Tuseng Po) segment 8 (Yunnan; DUS) (Yunnan; Qianli Zhijiang) (Yunnan; Wuxing) (Yunnan; source unknown)

Hexacopyge yichangensis — photo 5 — Photo 5 · this genus, distinguishing it from the two pairs of Remopleurides. Wenwei Hypostome specimen Holotype WIGM OT0038 (Yunnan) Pygidium and hypostome (Hubei; photograph courtesy of (collected by Prof. and Mrs. Zhou Zhiyi; Prof. Zhou Zhiqiang) photograph courtesy of Prof. Zhou specimens (Hunan; Zhiqiang) photograph courtesy of Prof. Zhou Zhiqiang) Enrolled specimen (Yunnan; Enrolled pygidium specimen (Yunnan; Specimen with an axial spine preserved on DUS) Tuyang Tuseng Po) segment 8 (Yunnan; DUS) (Yunnan; Qianli Zhijiang) (Yunnan; Wuxing) (Yunnan; source unknown)

Hexacopyge yichangensis — photo 6 — Photo 6 · this genus, distinguishing it from the two pairs of Remopleurides. Wenwei Hypostome specimen Holotype WIGM OT0038 (Yunnan) Pygidium and hypostome (Hubei; photograph courtesy of (collected by Prof. and Mrs. Zhou Zhiyi; Prof. Zhou Zhiqiang) photograph courtesy of Prof. Zhou specimens (Hunan; Zhiqiang) photograph courtesy of Prof. Zhou Zhiqiang) Enrolled specimen (Yunnan; Enrolled pygidium specimen (Yunnan; Specimen with an axial spine preserved on DUS) Tuyang Tuseng Po) segment 8 (Yunnan; DUS) (Yunnan; Qianli Zhijiang) (Yunnan; Wuxing) (Yunnan; source unknown)

Hexacopyge yichangensis — photo 7 — Photo 7 · this genus, distinguishing it from the two pairs of Remopleurides. Wenwei Hypostome specimen Holotype WIGM OT0038 (Yunnan) Pygidium and hypostome (Hubei; photograph courtesy of (collected by Prof. and Mrs. Zhou Zhiyi; Prof. Zhou Zhiqiang) photograph courtesy of Prof. Zhou specimens (Hunan; Zhiqiang) photograph courtesy of Prof. Zhou Zhiqiang) Enrolled specimen (Yunnan; Enrolled pygidium specimen (Yunnan; Specimen with an axial spine preserved on DUS) Tuyang Tuseng Po) segment 8 (Yunnan; DUS) (Yunnan; Qianli Zhijiang) (Yunnan; Wuxing) (Yunnan; source unknown)

Hexacopyge yichangensis — photo 8 — Photo 8 · this genus, distinguishing it from the two pairs of Remopleurides. Wenwei Hypostome specimen Holotype WIGM OT0038 (Yunnan) Pygidium and hypostome (Hubei; photograph courtesy of (collected by Prof. and Mrs. Zhou Zhiyi; Prof. Zhou Zhiqiang) photograph courtesy of Prof. Zhou specimens (Hunan; Zhiqiang) photograph courtesy of Prof. Zhou Zhiqiang) Enrolled specimen (Yunnan; Enrolled pygidium specimen (Yunnan; Specimen with an axial spine preserved on DUS) Tuyang Tuseng Po) segment 8 (Yunnan; DUS) (Yunnan; Qianli Zhijiang) (Yunnan; Wuxing) (Yunnan; source unknown)

Hexacopyge yichangensis — photo 9 — Photo 9 · this genus, distinguishing it from the two pairs of Remopleurides. Wenwei Hypostome specimen Holotype WIGM OT0038 (Yunnan) Pygidium and hypostome (Hubei; photograph courtesy of (collected by Prof. and Mrs. Zhou Zhiyi; Prof. Zhou Zhiqiang) photograph courtesy of Prof. Zhou specimens (Hunan; Zhiqiang) photograph courtesy of Prof. Zhou Zhiqiang) Enrolled specimen (Yunnan; Enrolled pygidium specimen (Yunnan; Specimen with an axial spine preserved on DUS) Tuyang Tuseng Po) segment 8 (Yunnan; DUS) (Yunnan; Qianli Zhijiang) (Yunnan; Wuxing) (Yunnan; source unknown)

Hexacopyge yichangensis — photo 10 — Photo 10 · this genus, distinguishing it from the two pairs of Remopleurides. Wenwei Hypostome specimen Holotype WIGM OT0038 (Yunnan) Pygidium and hypostome (Hubei; photograph courtesy of (collected by Prof. and Mrs. Zhou Zhiyi; Prof. Zhou Zhiqiang) photograph courtesy of Prof. Zhou specimens (Hunan; Zhiqiang) photograph courtesy of Prof. Zhou Zhiqiang) Enrolled specimen (Yunnan; Enrolled pygidium specimen (Yunnan; Specimen with an axial spine preserved on DUS) Tuyang Tuseng Po) segment 8 (Yunnan; DUS) (Yunnan; Qianli Zhijiang) (Yunnan; Wuxing) (Yunnan; source unknown)

Classification

Order Asaphida / Superfamily Remopleuridioidea / Family Remopleurididae Genus Hexacopyge Yuan & Zhou, 1998

Genus

Hexacopyge

Genus author

Yuan Wenwei, Zhou Zhiyi

Genus etymology

hexac-, hexacanthus, six-spined; -pyge, tail. Referring to the three pairs of pygidial pleural spines of

Species

H. yichangensis Zhou, Zhou & Yuan, 2004

Species author

Zhou Zhiqiang, Zhou Zhiyi, Yuan

Species etymology

Yichang, Yichang, Hubei, type locality of the type specimens

Age

Sandbian to Katian (Late Ordovician)

Distribution

Hubei, Hunan, Shaanxi, Chongqing, Yunnan

Diagnosis

Glabellar terrace lines weak and fine, not easily preserved; median area of the glabella transversely elliptical, anterior tongue with parallel sides or slightly widening forward, strongly bent downward anteriorly, three pairs of very shallow lateral glabellar furrows, expressed as smooth streaks interrupting the terrace-line ornament; anterior border furrow and anterior border both narrow and distinct; eye furrow deep and narrow; palpebral lobes long; eyes large; occipital furrow narrow and deep; occipital ring narrowing laterally, occipital node prominent, very close to the occipital furrow; librigenae very narrow with long, backward-laterally curved genal spines. Thorax of 11 segments; axis about twice the width of the pleurae, some specimens with a long axial spine on segment 8; pleural segments curved backward-laterally with sharp ends. Pygidium small; axis conical; pleural region flat with 3 pairs of pleural ribs, each extended into a pair of pleural spines, the first pair large and the posterior two pairs small.