Chelediscus
{{Short description|Genus of trilobites}}
{{Taxobox
| fossil_range = {{Geological range|519|516|Late Botomian}}{{cite journal
|last=SEPKOSKI
|first=J.
|title=A compendium of fossil marine animal genera (Trilobita entry)
|journal=Bulletins of American Paleontology
|volume=364
|page=560
|year=2002
|url=http://strata.ummp.lsa.umich.edu/jack/showgenera.php?taxon=307&rank=class
|accessdate=2008-01-12
|url-status=dead
|archiveurl=https://web.archive.org/web/20060905162524/http://strata.ummp.lsa.umich.edu/jack/showgenera.php?taxon=307&rank=class
|archivedate=2006-09-05
}}
| image = Chelediscus acifer linedrawing.jpg
| image_upright = 0.5
| image_caption = A drawing of a cephalon and pygidium of Chelediscus acifer
| regnum = Animalia
| phylum = Arthropoda
| classis = Trilobita
| ordo = Agnostida
| subordo = Eodiscina
| superfamilia = Eodiscoidea
| familia = Weymouthiidae
| genus = Chelediscus
| genus_authority = Rushton, 1966
| subdivision_ranks = Species
| subdivision =
- C. acifer Rushton, 1966 (type)
- C. chathamensis Rasetti, 1967
}}
ChelediscusRUSHTON, A. W. A. 1966. The Cambrian Trilobites from the Purley Shales of Warwickshire Palaeontographical Society Monographs (1): p. 19, pl. 2, figs. 26 a - e. is a genus of Eodiscinid trilobite belonging to the family Weymouthiidae Kobayashi T. (1943),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. Order Agnostida Salter (1864).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. The Treatise assigns this genus to the Calodiscidae; Cotton and Fortey (2005) COTTON T. J. and FORTEY R. A. Comparative morphology and relationships of the Agnostida. In book: Crustacea and Arthropod Relationships. however move it to the Weymouthiidae. Chelediscus lived during the later part of the Botomian stage.Image:Chelediscus enroled lateral view linedrawing.jpg. Chelediscus is known from upper lower Cambrian strata in England, Newfoundland, New York State and Russia (Rushton, 1966; Fletcher, 2003;FLETCHER, T. P. 2003. Ovatoryctocara granulata: The key to a global Cambrian Stage boundary and the correlation of the olenellid, redlichiid and paradoxidid realms. In Trilobites and their relatives (eds P. D. Lane, D. J. Siveter & R. A. Fortey), pp. 73–102. Special Papers
in Palaeontology no. 70. Rasetti, 1967;RASETTI, F., 1967. Lower and Middle Cambrian trilobite faunas from the Taconic sequence of New York. Smiths. mise. Coli., 152 (4), pp. 1 - 111, 14 pls. Jell in Kaesler, 1997;KAESLER, R. L. (ed.) 1997. Treatise on Invertebrate Paleontology. Part O. Arthropoda 1. Trilobita, Revised. Volume 1: Introduction, Order Agnostida, Order Redlichiida. Boulder, Colorado and Lawrence, Kansas: Geological Society of America and University of Kansas, 530 pp.
Distribution
- The holotype of C. acifer Rushton (1966, p. 19, pl. 2, figs. 26 a - e), is A 57104, held at the Sedgwick Museum of Earth Sciences, University of Cambridge and was collected by Rushton from about 450' above base of the Purley Shale Formation (Protolenus Biozone) at Camp Hill, St. Paul's Church, Stockingford, Nuneaton, Warwickshire, England [Closest ICS interval: Cambrian Series 3 – Terreneuvian Epoch].
C. acifer is also recorded from a Limestone at the top of the Torneträsk Formation, probably Ornamentaspis? linnarssoni Assemblage Zone, in the Luobakti section, south of Lake Torneträsk, northern Swedish Lapland AXHEIMER, N., AHLBERG P. & CEDERSTRÖM P., 2007. A new lower Cambrian eodiscoid trilobite fauna from Swedish Lapland and its implications for intercontinental correlation. Geol. Mag. 144 (6), 2007, pp. 953 – 961. Cambridge University Press, and the lower to middle Brigus Formation (Hupeolenus Zone; Tannudiscus balanus Subzone) at Cape St Mary's, Newfoundland (Fletcher, 2003).
- C. chathamensis Rasetti (1967, p. 46, pl. 3, figs. 11 - 17) was recovered from the Malden Bridge road cut, on Columbia County Route 32, about one mile W. of Malden Bridge, New York State. In the eastern part of the cut, a few medium-grey, granular, 1-3 inch thick limestone beds yielded a rather large Lower Cambrian faunule very similar to the Acimetopus bilobatus faunule from limestone exposures on the Griswold farm, about 1 mile southeast of North Chatham, Columbia County, New York State, USA. The strata holding this faunule are referred to as the Leptochilodiscus punctulatus beds.
==References==
{{Reflist}}
{{Taxonbar|from=Q368252}}
Category:Fossil taxa described in 1966
Category:Trilobites of North America
Category:Cambrian genus extinctions
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