Asaphida

Leiolonchodomas dangmengouensis

Order Asaphida / Superfamily Trinucleoidea / Family Raphiophoridae

Sandbian to Katian (Late Ordovician)Shaanxi

Leiolonchodomas dangmengouensis — photo 1 — Photo 1 · Liwen the loss of the posterior border furrow of the cranidium. Liwen Cranidium, holotype NIGP151079 (Shaanxi; photograph courtesy of Prof. Zhou Zhiqiang) Cranidium specimen (Shaanxi; photograph courtesy of Prof. Zhou Zhiqiang)

Leiolonchodomas dangmengouensis — photo 2 — Photo 2 · Liwen the loss of the posterior border furrow of the cranidium. Liwen Cranidium, holotype NIGP151079 (Shaanxi; photograph courtesy of Prof. Zhou Zhiqiang) Cranidium specimen (Shaanxi; photograph courtesy of Prof. Zhou Zhiqiang)

Classification

Order Asaphida / Superfamily Trinucleoidea / Family Raphiophoridae

Genus

Leiolonchodomas Zhou, Zhou & Xiang, 2016

Genus author

Zhou Zhiqiang, Zhou Zhiyi, Xiang

Genus etymology

leio-, Greek, smooth; Lonchodomas, a trilobite genus name. Referring to its degenerate occipital furrow and

Species

L. dangmengouensis Zhou, Zhou & Xiang, 2016

Species author

Zhou Zhiqiang, Zhou Zhiyi, Xiang

Species etymology

Dangmengouensis, Dangmengou, Hujiaba Town, Ningqiang County, Shaanxi

Age

Sandbian to Katian (Late Ordovician)

Distribution

Shaanxi

Diagnosis

Cranidium smooth and unornamented, triangular apart from the preglabellar spine; glabella spearhead-shaped, transversely convex, arched upward longitudinally, the highest point slightly in front of the transverse midline of the glabella, a weak longitudinal ridge present in the anterior part of the glabella; preglabellar spine medium-length, subcircular in cross-section, of small diameter, extending forward horizontally; glabellar furrows and muscle scars not visible; occipital furrow largely lost, only weak traces remaining beside the axial furrows. The occipital ring is also visible only near the axial furrows, extremely narrow; posterior border furrow absent; fixigenae triangular, narrowing from back to front.

Remarks

This species is the type species of the genus Leiolonchodomas.