Appleby, R. M. & Jones, G. L. 1976. The analogue video reshaper - a new tool for palaeontologists. Palaeontology 19, 565–86, pls 85–91.
Bérard, P. 1986. Trilobites de I'Ordovicien inférieur des Monts de Cabrières (Montagne Noire - France). Mèmoires du centre d'études et de recherches géologiques et hydrologiques 24, 1–220, 5 pls.
Bulman, O. M. B. & Rushton, A. W. A. 1973. Tremadoc faunas from boreholes in central England. Bulletin of the Geological Survey of Great Britain, no. 43, 1–40, 7 pls.
Cope, J. C. W. & Rushton, A. W. A. 1992. Cambrian and early Tremadoc rocks of the Llangynog Inlier, Dyfed, South Wales. Geological Magazine 129, 543–52.
Courtessole, R., Pillet, J., Vizcaino, D. & Eschard, R. 1985. Étude biostratigraphique et seditnentologique des Formations arenacés de I'Arenigien du Saint Chinianais oriental (Hérault) versant sud de la Montagne Noire (France méridionale). Mémoires de la Société d'Etudes Scientifiques de l'Aude. 99 pp. Carcassone.
Cowie, J. W., Rushton, A. W. A. & Stubblefield, C. J. 1972. A correlation of Cambrian rocks in the British Isles. Special Report of the Geological Society of London, no. 2, 42 pp.
Curtis, M. L. K. 1968. The Tremadoc rocks of the Torthworth inlier, Gloucestershire. Proceedings of the Geologists' Association 79, 349–62, pls 8, 9.
Dean, W. T. & Martin, F. 1978. Lower Ordovician acritarchs and trilobites from Bell Island, eastern Newfoundland. Bulletin of the Geological Survey of Canada no. 284, 1–35, 7 pls.
Fearnsides, W. G. 1910. The Tremadoc Slates and associated rocks of south-east Caernarvonshire. Quarterly Journal of the Geological Society of London 66, 142–88, pls 15–17.
Fortey, R. A. 1984. Global earlier Ordovician transgressions and regressions and their biological implications. In Aspects of the Ordovician System (ed. Bruton, D. L.), pp. 37–50. Oslo.
Fortey, R. A., Bassett, M. G., Harper, D. A. T., Hughes, R. A., Ingham, J. K., Molyneux, S. G., Owen, A. W., Owens, R. M., Rushton, A. W. A. & Sheldon, P. R. 1991. Progress and problems in the selection of stratotypes for the bases of series in the Ordovician System in the historical type area of the U.K. Geological Survey of Canada Paper 90–9, 5–25.
Fortey, R. A. & Owens, R. M. 1978. Early Ordovician (Arénig) stratigraphy and faunas of the Carmarthen district, south-west Wales. Bulletin of the British Museum (Natural History) Geology 30, 225–94, pls 1–11.
Fortey, R. A. & Owens, R. M. 1987. The Arenig Series in South Wales. Bulletin of the British Museum (Natural History) Geology 41, 69–305, 146 figs.
Fortey, R. A. & Owens, R. M. 1990. Arenig biostratigraphy and correlation in the Welsh Basin. Journal of the Geological Society 147, 607–10.
Fortey, R. A. & Owens, R. M. 1991. A trilobite fauna from the highest Shineton Shales in Shropshire, and the correlation of the latest Tremadoc. Geological Magazine 128, 437–64.
Harrington, H. J. & Leanza, A. F. 1957. Ordovician trilobites of Argentina. Special Publications, University of Kansas, Department of Geology, no. 1, 276 pp., 140 figs.
Henningsmoen, G. 1957. The trilobite family Olenidae. Skrifter utgitt av det Norske Videnskaps-Akademi i Oslo. I. Matematisk-Naturvidenskapelig Klasse 1957, no. 1, 1–303, 31 pls.
Krause, F. F. & Rowell, A. J. 1975. Distribution and systematics of the inarticulate brachiopods of the Ordovician carbonate mound of Meiklejohn Peak, Nevada. Paleontological contributions of the University of Kansas 61, 1–74, 12 pls.
Lake, P. 1919. A monograph of the British Cambrian trilobites (5), 89–120, pls 11–14. Monograph of the Palaeontographical Society no. 343, part of vol. 71 for 1917.
Lindholm, K. 1991. Ordovician graptolites from the early Hunneberg of southern Scandinavia. Palaeontology 34, 283–327.
Lynas, B. T. D. 1973. The Cambrian and Ordovician rocks of the Migneint area, North Wales. Quarterly Journal of the Geological Society of London 129, 481–503.
Lynas, B. D. T., Hains, B. A., Langford, R. L., Cave, R., Greig, D. C. & Wright, J. E. 1991. The Shelve Ordovician inlier and adjacent areas. British Geological Survey (parts of sheets SO 29, 39; SJ 20, 30).
Maletz, J., Rushton, A. W. A. & Lindholm, K. 1991. A new early Ordovician didymograptid, and its bearing on the correlation of the Skiddaw Group of England with the Tøyen Shale of Scandinavia. Geological Magazine 128, 335–43.
Molyneux, S. G. & Dorning, K. J. 1989. Acritarch dating of latest Tremadoc-earliest Arenig (early Ordovician) sediments in the Carmarthen district, south Wales. Geological Magazine 126, 707–14.
Molyneux, S. G. & Rushton, A. W. A. 1988. The age of the Watch Hill Grits (Ordovician), English Lake District: structural and palaeogeographical implications. Transactions of the Royal Society of Edinburgh: Earth Sciences 79, 43–69.
Nicoll, R. S., Nielsen, A. T., Laurie, J. R. & Shergold, J. H. 1991. Preliminary correlation of Payntonian (latest Cambrian) and Arenig (early Ordovician) sea level events in Australia and Scandinavia. Abstracts of the Vlth Ordovician Symposium, Sydney, p. 24.
Norford, B. S. 1988. Introduction to papers on the Cambrian-Ordovician boundary. Geological Magazine 125, 323–6.
Ranger, M. J., Pickerill, R. K. & Fillion, D. 1984. Lithostratigraphy of the Cambrian?-Lower Ordovician Bell Island and Wabana Groups of Bell, Little Bell and Kellys islands, Conception Bay, eastern Newfoundland. Canadian Journal of Earth Sciences 21, 1245–61.
Raw, F. 1925. The development of Leptoplastus salteri and other trilobites. Quarterly Journal of the Geological Society of London 81, 223–324, pls 15–18.
Rushton, A. W. A. 1985. A Lancefieldian graptolite from the Lake District. Geological Magazine 122, 329–33.
Rushton, A. W. A. 1988. Tremadoc trilobites from the Skiddaw Group in the English Lake District. Palaeontology 31, 677–98, pls 66–68.
Rushton, A. W. A. & Fortey, R. A. 1992. Tremadoc. In Atlas of Palaeogeography and Lithofacies (eds Cope, J. C. W., Ingham, J. K. and Rawson, P. F.). Geological Society Memoir no. 13.
Salter, J. W. 1859. In Murchison, R. I. Siluria, 3rd ed., xx + 592 pp., 41 pls. London.
Salter, J. W. 1866. On the fossils of North Wales. Appendix. In The geology of North Wales (ed. Ramsey, A. C.), pp. 239–363. Memoirs of the Geological Survey of Great Britain no. 3, viii + 381 pp., 28 pls.
Stubblefield, C. J. & Bulman, O. M. B. 1927. The Shineton Shales of the Wrekin district. Quarterly Journal of the Geological Society of London 83, 96–146, pls 3–5.
Thoral, M. 1946. Cycles géologiques et formations noduliferes de la Montagne Noire. Nouvelles Archives du Musé d'Histoire Naturelle de Lyon 1, 1–103, pls 1–16.
Tiernvik, T. E. 1956. On the early Ordovician of Sweden: stratigraphy and fauna. Bulletin of the Geological Institution of the University of Uppsala 36, 107–284, pls 1–11.
Walcott, C. D. 1898. Cambrian Brachiopoda: Obolus and Lingulella, with descriptions of new species. Proceedings of the United States National Museum 21, 385–420.
Walcott, C. D. 1912. Cambrian Brachiopoda. Monographs of the United States Geological Survey 51, 872 + 363 pp., 104 pls.
Whittard, W. F. 1931. The geology of the Ordovician and Valentian rocks of the Shelve Country, Shropshire. Proceedings of the Geologists' Association 42, 322–39, pls 10, 11.
Whittard, W. F. 1979. (ed. Dean, W. T.). An account of the Ordovician rocks of the Shelve Inlier in west Salop and part of North Powys. Bulletin of the British Museum (Natural History) Geology 33, 1–69.
Williams, A., Strachan, I., Bassett, D. A., Dean, W. T., Ingham, J. K., Wright, A. D. & Whittington, H. B. 1972. A correlation of Ordovician rocks in the British Isles. Special Report of the Geological Society of London, no. 3, 74 pp.
Williams, S. H. 1990. An Arenig graptolite from Bell Island, eastern Newfoundland - its biostratigraphic and palaeogeographic significance. Maritime Sediments and Atlantic Geology 26, 43–55.
Woodcock, N. H. 1990. Sequence stratigraphy of the Palaeozoic Welsh Basin. Journal of the Geological Society 147, 537–47.