Jinghediscus Explained

Jinghediscus Xiang & Zhang, 1985 ^[1] is a genus of Eodiscinid trilobite belonging to the family Weymouthiidae Kobayashi T. (1943),^[2] Order Agnostida (Salter 1864) ^[3] It lived during the lower Middle Cambrian, with remains found in China (Xinjiang) and Australia (Queensland).

Species

Jinghediscus nummularius Xiang and Zhang, 1985.

Description

Like all Weymouthiidae, Jinghediscus lacks eyes and facial sutures. Cephalon semi-elliptical. Glabella has one transglabellar furrow and inflated posterior lobe that widens towards rear. Preglabellar field broad (sag.) and confluent with uniformly wide (tr.) genal areas. Occipital ring (L0) ill-defined and without spine. cephalic border is only gently convex and of uniform width. Pygidium with strongly conical axis composed of ten axial rings; pleural fields smooth and defined from axis merely by a change in slope. Pygidial border broadens considerably towards rear and is wider (sag.) posteriorly than width (tr.) of the smooth pleural fields.^[4]

Notes and References

XIANG L. & ZHANG T. 1985. Chapter 3, Systematic description of trilobites. In: Stratigraphy and Trilobite Faunas of the Cambrian in the Western Part of Northern Tianshan, Xinjiang. Minist. Geol. Mineral Resour., Geol. Mem, Ser.2, 4: 1-243 [in Chinese with English summary].
KOBAYASHI T. 1943. Brief notes on the Eodiscids 1, their classification with a description of a new species and a new variety, Proceedings of the Imperial Academy, Tokyo, Volume 19, pp. 37-42.
SALTER, J. W. 1864: On some new fossils from the Lingula-flags of Wales. Quarterly Journal of the Geological Society of London, 20, 233–241.
Book: WHITTINGON, H. B. . 1997. Treatise on Invertebrate Paleontology. Part O, Revised. Volume 1 – Trilobita – Introduction, Order Agnostida, Order Redlichiida. 393–394.