Hostname: page-component-848d4c4894-75dct Total loading time: 0 Render date: 2024-06-03T14:28:02.862Z Has data issue: false hasContentIssue false

Taxonomy and distribution of chasmopine trilobites

Published online by Cambridge University Press:  01 May 2009

K. J. McNamara
Affiliation:
Western Australian Museum, Francis Street, Perth, Western Australia 6000, Australia

Summary

The Ordovician pterygometopid subfamily Chasmopinae is considered to include not only Chasmops McCoy, 1849, and Uralops Ancigin, 1970, but also a number of other genera which encompass species previously referred to Chasmops. These are: Toxochasmops McNamara, 1979; Scopelochasmops gen.nov.; Bolbochasmops gen.nov.; and Rollmops gen.nov. A close correlation is shown to exist between distribution of chasmopines and lithofacies, which indicates habitation in ashallow water environment. A westerly spread of chasmopine species at various times from eastern Baltoscandia is considered to correspond with a similar spread of the shallow water environment. This is shown by the periodic appearance of members of the subfamily in the Oslo region and Britain. Thereis a general reduction in number of chasmopine species and genera away fromthe eastern Baltic.

Type
Articles
Copyright
Copyright © Cambridge University Press 1980

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Ancigin, N. Ya. 1970. Trilobity semejctva Pterygometopidae iz ordovikskihk otlozenij urala (Trilobites of the family Pterygometopidae in Ordovician deposits of the Urals), pp. 1342 in Materialy po paleontologii Urala (Otv. red. M. G. Breivel', G. N. Papulov). Sverdlovsk.Google Scholar
Angelin, N. P. 1851. Palaeontologia Svecica. I. Iconographia crustaceorum formationis transitionis. Fasc. 1, 124. Holmiae.Google Scholar
Bjørlykke, K. 1974. Depositional history and geochemical composition of Lower Palaeozoic epicontinental sediments from the Oslo region. Norg.geol. Unders. 305, 181.Google Scholar
Bjørlykke, K. O. 1898. Geologisk kart med beskrivelse over Kristiania by. Norg. geol. Unders. 25, 186.Google Scholar
Boeck, C. 1838. Übersicht der bisher in Norwegen gefunden Formen der Trilobiten-Familie in Keilhau, B. M. Gaea norwegica, Teil 1, 138–45. Christiania.Google Scholar
Bolton, T. E. 1972. Geological map and notes on the Ordovician and Silurianlitho- and biostratigraphy, Anticosti Island, Quebec. Pap. geol. Surv. Can. 71–19, v, 144.Google Scholar
Brøgger, W. C. 1887. Geologisk kart over øerne Kristiania. Nyt. Mag. f. Naturvid. 31, 136.Google Scholar
Clarkson, E. N. K. & Henry, J. L. 1973. Structures coaptatives et enroulement chez quelques trilobites ordoviciens et siluriens. Lethaia 6, 105–32.Google Scholar
Dean, W. T. 1961. The Ordovician trilobite faunas of south Shropshire. II. Bull. Br. Mus. nat. Hist. (Geol.) 5, 311–58.Google Scholar
Eichwald, E. d', 1840. Über das silurische Schichtensystem in Esthland. St Petersburg.CrossRefGoogle Scholar
Haller, J. 1973. Die ordovizische trilobitengattung Chasmops aus baltoskandischen Geschieben. Paläont. Abh., Abt. A, 4, 723–68.Google Scholar
Jaanusson, V. 1960. Graptoloids from the Ontikan and Viruan (Ordov.) limestones of Estonia and Sweden. Bull. geol. Instn Univ. Uppsala 38, 289366.Google Scholar
Jaanusson, V. 1973. Aspects of carbonate sedimentation in the Ordovician ofBaltoscandia. Lethaia 6, 1134.CrossRefGoogle Scholar
Jaanusson, V. 1976. Faunal dynamics in the middle Ordovician (Viruan) of Balto-Scandia, pp. 301–26. In The Ordovician System: Proceedings of a Palaeontological Association symposium, Birmingham, September 1974 (ed. Bassett, M. G.). University of Wales Press.Google Scholar
Klöden, K. F. 1834. Die Versteinerungen der Mark Brandenburg. Berlin.Google Scholar
Männil, R. 1966. Istoriya razvitiya Baltiyskogo basseyna v ordovike. Eesti Teaduste Akad. Geol. Instn, Tallin. (In Russian with English summary: Evolution of the Baltic Basin during the Ordovician.)Google Scholar
McCoy, F. 1849. On the classification of some British fossil Crustacea, with notices of some new forms in the University Collection at Cambridge. Ann. Mag. nat. Hist. 2nd ser. 4, 392414.CrossRefGoogle Scholar
McNamara, K. J. 1979. Trilobites from the Coniston Limestone Group (AshgillSeries) of the Lake District, England. Palaeontology 22, 5392.Google Scholar
McNamara, K. J. In the press. Evolutionary trends and their functional significance in chasmopine trilobites. Lethaia, 13 (1).CrossRefGoogle Scholar
Miller, J. 1976. The sensory fields and life mode of Phacops rana (Green 1832) (Trilobita). Trans. roy. Soc. Edinb. 69, 337–67.Google Scholar
Öpik, A. 1937. Trilobiten aus Estland. Publ. geol. Instn Univ. Tartu, A 32 (3), 1163.Google Scholar
Pillet, J. 1954. La classification des Phacopacea (Trilobites). Bull. Soc. geol. Fr. ser. 6, 3, 817–39.Google Scholar
Pompeckj, J. F. 1890. Die Trilobitenfauna der Ost- und Westpreussischen Diluvialgeschiebe. Beitr. Naturk. Preuss. 7.Google Scholar
Reed, F. R. C. 1894. Woodwardian Museum Notes (on Phacops (Chasmops) Marri). Geol. Mag. dec. 4, 1, 241–6.Google Scholar
Reed, F. R. C. 1905. The classification of the Phacopidae. Geol. Mag. 52, 111.Google Scholar
Reed, F. R. C. 1906. The Lower Palaeozoic trilobites of the Girvan district, Ayrshire. Palaeontogr. Soc. (Monogr.): 3, 97186.CrossRefGoogle Scholar
Rõõmusoks, A. 1953. Novye dannye o trilobitach roda Chasmops iz ordovika Estonskoj SSR. (New data on the trilobite genus Chasmops from the Ordovician of the Estonian SSR). Loodusuurijate Seltsi Juubelikoguteos, 18531953, 396413. Tallin.Google Scholar
Rõõmusoks, A. 1970. Stratigrafiya viruskoy i harjuskoy seriy (ordovik) severnoy Estonii I. (Stratigraphy of the Viraun Series (middle Ordovician) in northern Estonia). Tartu Riiklik Ülikool, Tallin.Google Scholar
Salter, J. W. 1864. A monograph of the British trilobites from the Cambrian, Silurian and Devonian formations. Palaeontogr. Soc. (Monogr.) 1, 180.Google Scholar
Sars, M. & Boeck, C. 1838. Mag. f. Naturvid. 11, 2.Google Scholar
Schmidt, F. 1881. Revision der östbaltischen silurischen Trilobiten. Abt. 1. Phacopiden, Cheiruriden und Encrinuriden. Mem. Acad. Imp. Sci. St. Petersbourg. (7), 30, 1237.Google Scholar
Siegfried, P. 1938. Zur Kenntnis estländischer Trilobiten. Publ. geol. Instn. Univ. Tartu 54, 116.Google Scholar
Størmer, L. 1940. Early descriptions of Norwegian trilobites. The type specimens of C. Boeck, M. Sars and M. Esmark. Norsk geol. Tidsskr. 20, 113–51.Google Scholar
Størmer, L. 1945. Remarks on the Tretaspis Shales of Hadeland, with description of trilobite faunas. Norsk geol. Tidsskr. 25, 379426.Google Scholar
Størmer, L. 1953. The Middle Ordovician of the Oslo region, Norway. 1. Introduction to stratigraphy. Norsk geol. Tidsskr. 31, 37141.Google Scholar
Størmer, L. 1967. Some aspects of the Caledonian geosyncline and foreland west of the Baltic Shield. Jl geol. Soc. Lond. 123, 183214.CrossRefGoogle Scholar
Thorslund, P. 1940. On the Chasmops Series of Jemtland and Södermanland (Tvären). Sver. geol. Unders. Afh. Ser. C, 436, 1191.Google Scholar
Twenhofel, G. T. 1928. The geology of Anticosti Island. Mem. geol. Surv. Can. 154, 1481.Google Scholar
Warburg, E. 1925. The trilobites of the Leptaena Limestone in Dalarne. Bull. geol. Instn Univ. Uppsala, 17, 1162.Google Scholar
Wigand, G. 1888. Über die Trilobiten der silurischen Geschiebe in Mecklenburg. Z. dtsch. geol. Ges. 40, 39101.Google Scholar
Williams, A. 1969. Ordovician of the British Isles. In North Atlantic – geology and continental drift; a symposium (ed. Kay, M.). Mem. Amer. Ass. Petrol. Geol. 12, 236–64.Google Scholar
Wiman, C. 1901. Ü;ber die Borkholmer Schicht im Mittelbaltischen Silurgebeit. Bull. geol. Instn Univ. Uppsala 5, 149222.Google Scholar
Wiman, C. 1908. Studien über das nordbaltische Silurgebiet. Bull. geol. Instn Univ. Uppsala 8, 73168.Google Scholar
Whittington, H. B. 1962. A monograph of the Ordovician trilobites of the Bala area, Merioneth. Palaeontogr. Soc. (Monogr.): 1, 132.Google Scholar