Calodiscus

Superregnum: Eukaryota
Cladus: Unikonta
Cladus: Opisthokonta
Cladus: Holozoa
Regnum: Animalia
Subregnum: Eumetazoa
Cladus: Bilateria
Cladus: Nephrozoa
Cladus: Protostomia
Cladus: Ecdysozoa
Cladus: Panarthropoda
Phylum: Arthropoda
Subphylum: †Trilobitomorpha
Classis: †Trilobita
Ordo: †Agnostida
Subordo: †Eodiscina
Superfamilia: †Eodiscoidea

Familia: † Calodiscidae
Genus: † Calodiscus
Species: C. lobatus
Name

Calodiscus Howell 1935
Synonyms

Goniodiscus Raymond, 1913
Brevidiscus Kobayashi, 1943

Homonym

Calodiscus, Diatom (Bacillariophyta) alga.

References
Cederström, P., Ahlberg, P., Clarkson, E., Nilsson, C., & Axheimer, N., 2009 "The lower Cambrian eodiscoid trilobite Calodiscus lobatus from Sweden: morphology, ontogeny and distribution" Palaeontology 52(3):491 - 539

Calodiscus is a genus of Eodiscinid trilobite in the family Calodiscidae.[3] 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].[4][5]

Lochman (1956)[6] demonstrated that Calodiscus agnostoides (Kobayashi, 1943) represents late meraspid instars of C. lobatus (Cederström et al., 1988, p. 500).
References

HOWELL, B. F. 1935. Cambrian and Ordovician trilobites from Herault, southern France. Journal of Paleontology 9(3): 222 - 238
XIANG, L. W. & ZHANG, T. R. 1985. Systematic description of the trilobites. In Stratigraphy and Trilobite Faunas of the Cambrian in the Western Part of Northern Tianshan, Xinjiang (Wang, J. B. et al., eds), Ministry of Geology and Mineral Resources, Geological Memoirs, Series 2, 4, 64 - 165. Geological Publishing House, Beijing [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.
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.
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.
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.