Hostname: page-component-cd9895bd7-8ctnn Total loading time: 0 Render date: 2024-12-27T08:04:03.421Z Has data issue: false hasContentIssue false

The uppermost Ordovician (Hirnantian) trilobites of Girvan, SW Scotland with a review of coeval trilobite faunas

Published online by Cambridge University Press:  03 November 2011

Alan W. Owen
Affiliation:
Department of Geology, The University, Dundee DD1 4HN, Scotland.

Abstract

The uppermost Ordovician (Hirnantian) trilobite fauna of the High Mains Formation in the Craighead Inlier near Girvan comprises species of Flexicalymene, Achatella, Hemiarges, Isotelus and an indeterminate proetid. All are illustrated and the first three including Hemiarges extremus sp. nov. are described. This is one of the most diverse Hirnantian trilobite assemblages known. The beginning of the Hirnantian marked a profound global decrease in trilobite diversity and an overall increase in endemicity with many genera persisting only as local relicts. Many faunas include a dalmanitid (Mucronaspis or Dalmanitina) and the absence of this family suggests a shallow shelf environment for the High Mains fauna which comprises relicts of earlier lineages in the area. Some genera have yet to be discovered in the Hirnantian, but are recorded from both older and younger strata. Like many of the known Hirnantian taxa, they must have survived in localised faunas before becoming widespread again in the Silurian. Limited evidence suggests that the spread of cold/deep water trilobites, notably Mucronaspis / Dalmanitina, on to low latitude shelves preceded the major trilobite extinction at the Rawtheyan-Hirnantian boundary, but this would still be within the timescale suggested by other workers for a rapid onset of the late Ordovician glaciation and the consequent ecological disruption.

Type
Research Article
Copyright
Copyright © Royal Society of Edinburgh 1986

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

Apollonov, M. K., Bandaletov, S. M. & Nikitin, I. F. (eds) 1980. Granitsa Ordovika i Silura U Kazakhstane. Alma Ata: “Nauka” Kazakh SSR Publishing House.Google Scholar
Baird, W. J. 1980. A catalogue of Trilobites in the Royal Scottish Museum Edinburgh. R SCOTT MUS INF SER GEOL 8, 172.Google Scholar
Baldis, B. A. & Blasco, G. 1975. Primeros trilobites ashgillianos del Ordovicio Sudamericano. ACT AS I CONGR ARGENT PALEONTOL BIOESTR 1, 3348.Google Scholar
Bergström, J. 1968. Upper Ordovician Brachiopods from Västergötland, Sweden. GEOL PALAEONTOL 2, 135.Google Scholar
Billings, E. 1860. Descriptions of some new species of fossils from the Lower and Middle Silurian rocks of Canada. CAN NAT GEOL 5, 4969.Google Scholar
Bolton, T. E. 1972. Geological map and notes on the Ordovician and Silurian litho- and biostratigraphy, Anticosti Island, Quebec. GEOL SURV CAN PAP 7119, 145.Google Scholar
Brenchley, P. J. & Cocks, L. R. M. 1982. Ecological associations in a regressive sequence: the latest Ordovician of the Oslo-Asker district, Norway. PALAEONTOLOGY 25, 783815.Google Scholar
Brenchley, P. J. & Cullen, B. 1984. The environmental distribution of associations belonging to the Hirnantia fauna—Evidence from North Wales and Norway. In Bruton, D. L. (ed.) Aspects of the Ordovician System, 113125. Oslo: Universitetsforlaget.Google Scholar
Brenchley, P. J. & Newall, G. 1984. Late Ordovician environmental changes and their effect on faunas. In Bruton, D. L. (ed) Aspects of the Ordovician System, 6579. Oslo: Universitetsforlaget.Google Scholar
Campbell, K. S. W. 1973. A species of the trilobite Dalmanitina (Dalmanitina) from Australia. GEOL FÖREN STOCKH FÖRH 95, 6977.CrossRefGoogle Scholar
Chatterton, B. D. E., Lespérance, P. J. & Ludvigsen, R. 1983. Trilobites from the Ordovician—Silurian boundary of Anticosti Island, Eastern Canada. In Papers for the symposium on the Cambrian-Ordovician and Ordovician-Silurian boundaries, Nanjing, China. October 1983. NANJING INST GEOL PALAEONTOL, ACAD SINICA, 144–5.Google Scholar
Chatterton, B. D. E. & Ludvigsen, R. 1983. Trilobites of the Ordovician–Silurian boundary of the MacKenzie Mountains, northwestern Canada. In Papers for the symposium on the Cambrian–Ordovician and Ordovician-Silurian boundaries, Nanjing, China. October 1983. NANJING INST GEOL PALAEONTOL, ACAD SINICA, 146–7.Google Scholar
Chugaeva, M. N. 1983. [Trilobites]. In [The Ordovician–Silurian boundary in the Northeast of the USSR]. TR MEZHVED STRATIGR KOM SSSR 11, 7397.Google Scholar
Clarkson, E. N. K. & Howells, Y. 1981. Upper Llandovery trilobites from the Pentland Hills, Scotland. PALAEONTOLOGY 24, 507–36.Google Scholar
Cocks, L. R. M. & Copper, P. 1981. The Ordovician-Silurian boundary at the eastern end of Anticosti Island. CAN J EARTH SCI 18, 1029–34.Google Scholar
Cocks, L. R. M. & Fortey, R. A. 1982. Faunal evidence for oceanic separations in the Palaeozoic of Britain. J GEOL SOC LONDON 139, 465–78.Google Scholar
Cocks, L. R. M. & Fortey, R. A. 1986. New evidence on the South African Lower Palaeozoic: age and fossils reviewed. GEOL MAG 123, 437–44.CrossRefGoogle Scholar
Cocks, L. R. M. & Price, D. 1975. The biostratigraphy of the upper Ordovician and lower Silurian of south-west Dyfed, with comments on the Hirnantia fauna. PALAEONTOLOGY 18, 703–24.Google Scholar
Dean, W. T. 1963. The Ordovician trilobites of South Shropshire III. BULL BR MUS (NAT HIST) GEOL 7, 215–54.Google Scholar
Delo, D. M. 1935. A revision of the Phacopid trilobites. J PALEONTOL 9, 402–20.Google Scholar
Gürich, G. 1901. Über eine neue Lichas–Art aus dem Devon von Neu Süd-Wales und über die Gattung Lichas überhaupt. NEUES JAHRB MIN GEOL PÄLAONT 14, 519–39.Google Scholar
Harper, D. A. T. 1981. The stratigraphy and faunas of the Upper Ordovician High Mains Formation of the Girvan district. SCOTT J GEOL 17, 247–55.Google Scholar
Harper, D. A. T. 1982. The stratigraphy of the Drummuck Group (Ashgill), Girvan. GEOL J 17, 251–77.Google Scholar
Havlíček, V. & Vaněk, J. 1966. The Biostratigraphy of the Ordovician of Bohemia. SB GEOL VED PALEONT 8, 769.Google Scholar
Hawle, I. & Corda, A. J. C. 1847. Podrom einer Monographie der böhmischen Trilobiten. Prague.Google Scholar
Holloway, D. J. 1981. Silurian Dalmanitacean trilobites from North America, and the subfamilies Dalmanitinae and Synphoriinae. PALAEONTOLOGY 24, 695731.Google Scholar
Howells, Y. 1982. Scottish Silurian Trilobites. PALAEONTOGR SOC MONOGR.Google Scholar
Ingham, J. K. 1966. The Ordovician rocks in the Cautley and Dent districts of Westmorland and Yorkshire. PROC YORKSHIRE GEOL SOC 35, 455505.CrossRefGoogle Scholar
Ingham, J. K. 1977. A monograph of the upper Ordovician trilobites from the Cautley and Dent districts of Westmorland and Yorkshire. Part 3. PALAEONTOGR SOC MONOGR.Google Scholar
Ingham, J. K. 1978. Geology of a continental margin 2: middle and late Ordovician transgression, Girvan. In Bowes, D. R. & Leake, B. E. (eds) Crustal evolution in northwestern Britain and adjacent regions, 163–76. GEOL J SPEC ISSUE 10.Google Scholar
Jaanusson, V. 1956. Untersuchungen über der oberordovizischen Lykholm-Stufenkomplex in Estland. BULL GEO INST UNIV UPPSALA 36, 369400.Google Scholar
Jaanusson, V. 1979. Ordovician. In Robison, R. A. & Teichert, C. (eds) Treatise on Invertebrate Paleontology Part A. Introduction, A13666. Lawrence, Kansas: Geol Soc. Am. + Univ. Kansas Press.Google Scholar
Jaanusson, V. 1982. Ordovician in Västergötland. in Bruton, D. L. & Williams, S. H. (eds) Field excursion guide IV. Int. Symp. Ordovician System. PALEONTOL CONTRIB UNIV OSLO 279, 164–83.Google Scholar
Karis, L. & Larsson, K. 1982. Jämtland Road-Log. In Bruton, D. L. & Williams, S. H. (eds). Field excursion guide IV. Int. Symp. Ordovician System. PALEONTOL CONTRIB UNIV OSLO 279, 6476.Google Scholar
Kielan, Z. 1960. Upper Ordovician trilobites from Poland and some related forms from Bohemia and Scandinavia. PALEONTOL POLON 11, 1198.Google Scholar
Lamont, A. 1935. The Drummuck Group, Girvan; A stratigraphical revision with descriptions of new fossils from the lower part of the group. TRANS GEOL SOC GLASGOW 19, 288332.Google Scholar
Lamont, A. 1949. New Species of Calymenidae from Scotland and Ireland. GEOL MAG 86, 313–23.Google Scholar
Lamont, A. 1965. Gala-Tarannon Trilobites and an Ostracod from the Hagshaw Hills, Lanarkshire. SCOTT J SCI 1, 3346 (privately published).Google Scholar
Lespérance, P. J. 1974. The Hirnantian fauna of the Percé area (Québec) and the Ordovician–Silurian boundary. AM J SCI 274, 1030.Google Scholar
Lespérance, P. J. 1985. Faunal distribution across the Ordovician-Silurian boundary, Anticosti Island and Percé Québec, Canada. CAN J EARTH SCI 22, 838–49.Google Scholar
Lespérance, P. J. & Sheehan, P. M. 1976. Brachiopods from the Hirnantian Stage (Ordovician-Silurian) at Percé, Québec. PALAEONTOLOGY 19, 719–31.Google Scholar
Lespérance, P. J. & Sheehan, P. M. 1981. Hirnantian fauna in and around Percé, Québec. In Lespérance, P. J. (ed.) Subcommission on Silurian Stratigraphy. Ordvician-Silurian boundary Working Group. Field Meeting Anticosti-Gaspé, Québec 1981. Vol. 2: Stratigraphy and Palaeontology. Montreal: Départment de géologie, Université de Montreal.Google Scholar
Ludvigsen, R. & Chatterton, B. D. E. 1982. Ordovician Pterygometopidae (Trilobita) of North America. CAN J EARTH SCI 19, 21792206.CrossRefGoogle Scholar
Marek, L. & Havlíček, V. 1967. The articulate brachiopods of the Kosov Formation (Upper Ashgillian). ÚSTRED ÚSTAVU GEOL 17, 275–84.Google Scholar
McNamara, K. J. 1979. Trilobites from the Coniston Limestone Group (Ashgill Series) of the Lake District, England. PALAEONTOLOGY 22, 5392.Google Scholar
McNamara, K. J. 1980. Evolutionary trends and their functional significance in chasmopine trilobites. LETHAIA 13, 6178.Google Scholar
Milne Edwards, H. 1840. Histoire naturelle des Crustacés, comprenant I'Anatomie, la physiologie et la classification de ces animaux. Vol. 3. Paris.Google Scholar
Nicholson, H. A. & Etheridge, R. 1879. A monograph of the Silurian fossils of the Girvan district in Ayrshire, with special reference to those contained in the ‘Gray Collection’ Vol 1, Part 2, 137236. Edinburgh: Blackwood.Google Scholar
Öpik, A. A. 1937. Trilobiten aus Estland. ACTA COMM UNIV TARTU (A) 32, 1163.Google Scholar
Owen, A. W. 1980. The trilobite Tretaspis from the upper Ordovician of the Oslo region, Norway. PALAEONTOLOGY 23, 715–47.Google Scholar
Owen, A. W. 1981. The Ashgill trilobites of the Oslo Region, Norway. PALAEONTOGR ABT A 175, 188.Google Scholar
Owen, A. W. 1982 (for 1981). The trilobite Mucronaspis in the uppermost Ordovician of the Oslo Region, Norway. NOR GEOL TIDSSKR 61, 271–9.Google Scholar
Portlock, J. E. 1843. Report on the geology of Londonderry and parts of Tyrone and Fermanagh. Dublin: Andrew Milliken.Google Scholar
Poulsen, V. 1978. Dalmanitina beds (late Ordovician) on Bornholm. DANM GEOL UNDERS ÅRB 1976, 5387.Google Scholar
Reed, F. R. C. 1905. The classification of the Phacopidae. GEOL MAG Dec 5, 2, 172–8, 224–8.Google Scholar
Reed, F. R. C. 1914. The Lower Palaeozoic trilobites of Girvan. Supplement. PALAEONTOGR SOC MONOGR.Google Scholar
Reed, F. R. C. 1935. The Lower Palaeozoic trilobites of Girvan. Supplement 3. PALAEONTOGR SOC MONOGR.Google Scholar
Rong, Jia-yu 1984. Distribution of the Hirnantia fauna and its meaning. In Bruton, D. L. (ed.) Aspects of the Ordovician System, 101112. Oslo: Universitetsforlaget.Google Scholar
Ross, R. J. Jnr 1967. Calymenid and other Ordovician Trilobites from Kentucky and Ohio. PROF PAP US GEOL SURV 583–B, Bl19.Google Scholar
Ross, R. J. Jnr et al. 1982. The Ordovician System in the United States. INT UNION GEOL SCI PUBL 12, 173.Google Scholar
Salter, J. W. 1865. A monograph of the British trilobites from the Cambrian, Silurian and Devonian formations. PALAEONTOGR SOC MONOGR.Google Scholar
Schmidt, F. 1885. Revision der ostbaltischen silurischen Trilobiten Abt 2. Acidaspiden & Lichiden. MEM AKAD IMP SCI ST PETERSBURG (7) 33, (1) 1124.Google Scholar
Shaw, F. C. & Fortey, R. A. 1977. Middle Ordovician fades and trilobite faunas in N. America. GEOL MAG 114, 409–43.Google Scholar
Xinfu, Sheng 1982. [On the distribution and Age of the Hirnantia Fauna and the Dalmanitina Beds in China] BULL INST GEOL CHINESE ACAD GEOL SCI 6, 3156 [In Chinese with English summary.]Google Scholar
Shirley, J. 1936. Some British trilobites of the family Calymenidae Q J GEOL SOC LONDON 92, 384422.Google Scholar
Siveter, D. J. 1977. The Middle Ordovician of the Oslo Region, Norway, 27. Trilobites of the family Calymenidae. NOR GEOL TIDSSKR 56, 335–96.Google Scholar
Siveter, D. J., Ingham, J. K., Rickards, R. B. & Arnold, B. 1980. Highest Ordovician trilobites and graptolites from County Cavan, Ireland. J EARTH SCI R DUBLIN SOC 2, 193207.Google Scholar
Stanley, S. M. 1984. Temperature and biotic crises in the marine realm. GEOLOGY 12, 205–8.Google Scholar
Stanley, S. M. 1984a. Reply [to comment by J. G. Johnson]. Temperature and biotic crises in the marine realm. GEOLOGY 12, 741–2.Google Scholar
Temple, J. T. 1965. Upper Ordovician brachiopods from Poland and Britain. ACTA PALAEONTOL POLON 10, 379427.Google Scholar
Temple, J. T. 1969. Lower Llandovery (Silurian) trilobites from Keisley, Westmorland. BULL BR MUS (NAT HIST) GEOL 18, 197230.Google Scholar
Thomas, A. T. 1977. Classification and phylogeny of homalonotid trilobites. PALAEONTOLOGY 20, 159–78.Google Scholar
Thomas, A. T., Owens, R. M. & Rushton, A. W. A. 1984. Trilobites in British stratigraphy. GEOL SOC SPEC REP 16, 178.Google Scholar
Tripp, R. P. 1957. The classification and evolution of the superfamily Lichacea (Trilobita). GEOL MAG 94, 104–22.Google Scholar
Tripp, R. P. 1958. Stratigraphical and geographical distribution of the named species of the trilobite superfamily Lichacea. J PALEONTOL 32, 754–82.Google Scholar
Tripp, R. P. & Evitt, W. R. 1981. Silicified Lichidae (Trilobita) from the Middle Ordovician of Virginia. GEOL MAG 118, 665–77.Google Scholar
Xaofeng, Wang et al. 1983. Latest Ordovician and earliest Silurian faunas from the eastern Yangtze Gorges, China, with comments on Ordovician–Silurian boundary. BULL YICHANG INST GEOL MIN RESOURC CHINESE ACAD GEOL SCI 6, 129–82.Google Scholar
Whittington, H. B. 1971. Silurian calymenid trilobites from the United States, Norway and Sweden. PALAEONTOLOGY 14, 455–77.Google Scholar
Williams, A. et al. 1972. A correlation of Ordovician rocks in the British Isles. GEOL SOC SPEC REP 3, 174.Google Scholar
Williams, A. & Wright, A. D. 1981. The Ordovician–Silurian Boundary in the Garth area of southwest Powys, Wales. GEOL J 16, 139.Google Scholar
Wright, A. D. 1968. A westward extension of the Upper Ashgillian Hirnantia fauna LETHAIA 1, 352–67.Google Scholar
Wright, A. D. 1985. The Ordovician-Silurian boundary at Keisley, northern England. GEOL MAG 122, 261–73.Google Scholar
Zhaoling, Zhu & Hongji, Wu 1983. Late Ashgillian trilobites from Huanghuachang, Yichang County, Hubei Province. In Papers for the symposium on the Cambrian-Ordovician and Ordovician–Silurian boundaries, Nanjing, China. October 1983. NANJING INST GEOL PALAEONTOL, ACAD SINICA, 112120.Google Scholar