Runcinodiscus

Runcinodiscus Rushton (in Bassett et al. 1976, p. 636-7) [1] is a genus of Lower Cambrian Eodiscinid trilobite belonging to the family Weymouthiidae Kobayashi T. (1943),[2] Order Agnostida (Salter 1864).[3]

Runcinodiscus
Temporal range: Late Botomian
Scientific classification
Kingdom:
Animalia
Phylum:
Arthropoda
Class:
Trilobita
Order:
Agnostida
Suborder:
Eodiscina
Superfamily:
Eodiscoidea
Family:
Weymouthiidae
Genus:
Runcinodiscus

Rushton, 1976
species
  • R. index
  • R. cf. index

Type Species

By Monotypy and original designation, Runcinodiscus index Rushton (in Bassett et al. 1976). Holotype is A 15360 in the collection of the Sedgwick Museum of Earth Sciences, University of Cambridge.

Locality and age

The Type specimen (Cobbold, 1931) was collected from the Protolenus Limestone (Ac5) [Comley Series], 180m south of Comley Quarry, near Church Stretton, Shropshire, England [Grid Ref. SO 4849 9625].

Remarks

Fletcher & Theokritoff (2008) [4] designated Shaw’s (1950, pl. 79, fig. 24) [5] specimen of “ Weymouthia nobilis (Ford, 1872)” [6] as the holotype of a new species, Serrodiscus weymouthioides, and considered Runcinodiscus Rushton (in Bassett et al., 1976) [= ?Weymouthia nobilis (Ford, 1872)] to be a junior synonym of Serrodiscus; Rushton (1976) had previously regarded Weymouthia and Runcinodiscus as closely allied with Serrodiscus. Weymouthia nobilis (Ford 1872), first described from the Taconic region of New York State, is also recorded from the Protolenus Limestone (Ac5) [Protolenid-Strenuellid Zone] at Comley, Shropshire, England (Cobbold 1931),[7] but Rushton (in Bassett et al., 1976, p. 637) showed that the English specimens are specifically distinct from W. nobilis as described by Ford (1872), and thus erected his new genus and species, Runcinodiscus index.

Runcinodiscus cf. index Rushton (Ahlberg, 1983, p. 289, fig. 1),[8] described originally by Kiær (1917) [9] as Weymouthia nobilis, was recovered from the Lower Cambrian Holmia Shale at Tømten, close to Lake Mjøsa, Southeast Norway.

References
  1. BASSETT M. G., OWENS R. M., and RUSHTON A. W. A. 1976. Lower Cambrian fossils from the Hell’s Mouth Grits, Journal of the Geological Society 132 (6): 623–644.
  2. 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.
  3. 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.
  4. FLETCHER, T. P. & THEOKRITOFF, G., 2008. The Early Cambrian of eastern Massachusetts. Northeastern Geology and Environmental Science, 30, 301-329.
  5. SHAW, A. B., 1950. A revision of several Early Cambrian trilobites from eastern Massachusetts. Journal of Paleontology, 24, 577-590.
  6. FORD, S. W., 1872. Descriptions of some new species of primordial fossils. American Journal of Science, Series 3, 3, 419-422.
  7. COBBOLD, E. S. 1931: Additional fossils from the cambrian rocks of Comley, Shropshire. Q. J. Geo/. Soc. Lond. 87, 459 - 511.
  8. AHLBERG, P.: Redescription of a Lower Cambrian eodiscid trilobite from Norway. Norsk Geologisk Tidsskrift, Vol. 63, pp. 289 - 290. Oslo.
  9. KIÆR, J. 1917: The Lower Cambrian Holmia fauna at Tømten in Norway. Skr. Nor. Videnskapsselsk., l. Mat.-Naturvidensk. Kl. 1916, (10), 140 pp.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.