Calodiscus Explained

Calodiscus is a genus of Eodiscinid trilobite in the family Calodiscidae.^[1] It lived during the late Lower Cambrian, with remains found in Canada (Newfoundland & Labrador), the United States (Massachusetts, New York State), Greenland, The United Kingdom (England), Sweden, France, Germany, Italy (Sardinia), Kazakhstan, the Russian Federation and China.

The type species by original designation is Agnostus lobatus Hall, 1847 from the upper part of the lower Cambrian Browns Pond Formation (formerly Schodack Formation) at Troy in the Taconic region of New York State, USA [= ''Calodiscus korolevi'' Pokrovskaya ''in'' Ergaliev and Pokrovskaya, 1977; ''Calodiscus lakei'' Rasetti, 1952; and ''Calodiscus'' n. sp. A of Geyer, 1988, according to Cederström ''et al''., 1988].^{[2] [3]}

Lochman (1956)^[4] demonstrated that Calodiscus agnostoides (Kobayashi, 1943) represents late meraspid instars of C. lobatus (Cederström et al., 1988, p. 500).

Notes and References

1. 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.
2. HALL, J. 1847. Palaeontology: Volume 1. Containing descriptions of the organic remains of the lower division of the New-York System. Natural history of New York, Albany. 338 pp.
3. CEDERSTRÖM, P., AHLBERG, P., CLARKSON, E. N. K., NILSSON, C. H. and AXHEIMER, N. 1988. The Lower Cambrian eodiscoid trilobite Calodiscus lobatus from Sweden: Morphology, ontogeny and distribution. Palaeontology, Vol. 52, Part 3, 2009, pp. 491 – 53.
4. LOCHMAN, C. 1956. Stratigraphy, paleontology, and paleogeography of the Elliptocephala asaphoides strata in Cambridge and Hoosick Quadrangles, New York. Bulletin of the Geological Society of America, 67, 1331 – 1396.