Hostname: page-component-586b7cd67f-2brh9 Total loading time: 0 Render date: 2024-11-27T21:13:18.278Z Has data issue: false hasContentIssue false

A numerical taxonomic study of species of Trinucleidae (Trilobita) from the British Isles

Published online by Cambridge University Press:  03 November 2011

J. T. Temple
Affiliation:
Department of Geology, Birkbeck College, 7/15 Gresse Street, London W1P 1PA.

Abstract

British and Irish species of the trilobite family Trinucleidae are investigated by numerical taxonomie methods. Forty-five attributes are defined, relating mainlyto the dorsal surface of the cephalon, and several of them representing new concepts. Of the 106 described species from the British Isles, 31 are fully codable on the basis of topo types. An analysis is based on these species, together with 28 partly topotypically codable species and samples of 9 other species (undescribed, non-topotypic or non-British). The relations of the species are depicted in an ordination derived by principal components analysis of the interattribute correlation matrix and with superimposed minimal spanning tree. On the basis of the ordination most of the analysed species can be grouped into two subfamilies, Trinucleinae and Cryptolithinae (including Marrolithinae); thersites is excluded from Reedolithinae. Trinucleinae and Cryptolithinae are strongly differentiated on the y1 axis of the ordination. The two subfamilies show parallel evolution during the Ordovician in general cranidial attributes (e.g. increasing length, declination of fringe). In Trinucleinae the fringe also shows evolutionary changes (e.g. increases in numbers and regularity of arcs); in Cryptolithinae the fringe evolves very little. Ordination of the attributes is by non-linear mapping based on a distance matrix derived from the interattribute correlation matrix by the transformation (tanh-1|r|)-1. Lectotypes of 12 species are here selected: albidus Reed, ceryx Lamont, gibbsii Salter, girvanensis Lamont, hibernicus Reed, inconstans Whittard, persulcatus Reed, praeterita Reed, rhodesi Whittard, sortita Reed, subradiatus Reed and thersites Salter.

Type
Research Article
Copyright
Copyright © Royal Society of Edinburgh 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

Bancroft, B. B. 1929. Some new species of Cryptolithus, (s.I.), from the Upper Ordovician. MEM PROC MANCHESTER LIT PHILOS SOC 73, 6798.Google Scholar
Bancroft, B. B. 1949. Upper Ordovician trilobites of zonal value in south-east Shropshire. PROC R SOC LONDON [B] 136, 291315.Google ScholarPubMed
Born, A. 1921. Eine Untersilurfauna aus den Montagnes noires (Centralplateau). SENCKENBERGIANA 3, 181–93.Google Scholar
Cave, R. 1957. Salterolithus caractaci (Murchison) from Caradoc Strata near Welshpool, Montgomeryshire. GEOL MAG 94, 281–90.CrossRefGoogle Scholar
Cave, R. 1960. A new species of Tretaspis from South Wales. GEOL MAG 97, 334–7.CrossRefGoogle Scholar
Davis, J. C. 1973. Statistics and data analysis in geology. New York: Wiley.Google Scholar
Dean, W. T. 1960. The Ordovician trilobite faunas of South Shropshire, I. BULL BR MUS NAT HIST [GEOL] 4, 71143.Google Scholar
Dean, W. T. 1961. Trinucleid trilobites from the higher Dufton Shales of the Caradoc Series in the Cross Fell Inlier. PROC YORKSHIRE GEOL SOC 33, 119–34.CrossRefGoogle Scholar
Dean, W. T. 1962. The trilobites of the Caradoc Series in the Cross Fell Inlier of Northern England. BULL BR MUS NAT HIST [GEOL] 7, 65134.Google Scholar
Dean, W. T. 1963. The Ordovician trilobite faunas of South Shropshire, IV. BULL BR MUS NAT HIST [GEOL] 9, 118.Google Scholar
Dean, W. T. 1966. The Lower Ordovician stratigraphy and trilobites of the Landeyran Valley and the neighbouring district of the Montagne Noire, south-western France. BULL BR MUS NAT HIST [GEOL] 12, 245353.Google Scholar
Dean, W. T. 1971. The trilobites of the Chair of Kildare Limestone (Upper Ordovician) of eastern Ireland. Part I. PALAEONTOGR SOC MONOGR 160.Google Scholar
Elles, G. L. 1940. The stratigraphy and faunal succession in the Ordovician rocks of the Builth-Llandrindod inlier, Radnorshire. Q J GEOL SOC LOND 95, 383444.CrossRefGoogle Scholar
Fearnsides, W. G., Elles, G. L. and Smith, B. 1907. The Lower Palaeozoic rocks of Pomeroy. PROC R IRISH ACAD [B] 26, 97128.Google Scholar
Fortey, R. A. and Owens, R. M. 1978. Early Ordovician (Arenig) stratigraphy and faunas of the Carmarthen district, south-west Wales. BULL BR MUS NAT HIST [GEOL] 30, 225–94.Google Scholar
Gower, J. C. and Ross, G. J. S. 1969. Minimum spanning trees and single linkage cluster analysis. APPL STAT 18, 5464.CrossRefGoogle Scholar
Harper, J. C. and Romano, M. 1967. Decordinaspis—a new Caradoc trinucleid trilobite from the Ordovician of Ireland. PROC R IRISH ACAD [B] 65, 305–8.Google Scholar
Hicks, H. 1875. On the succession of the ancient rocks in the vicinity of St. David's, Pembrokeshire, with special reference to those of the Arenig and Llandeilo Groups, and their fossil contents. Q J GEOL SOC LOND 31, 167–93.CrossRefGoogle Scholar
Hughes, C. P. 1971. The Ordovician trilobite faunas of the Builth-Llandrindod inlier, Central Wales. Part II. BULL BR MUS NAT HIST [GEOL] 20, 115–82.Google Scholar
Hughes, C. P., Ingham, J. K. and Addison, R. 1975. The morphology, classification and evolution of the Trinucleidae (Trilobita). PHILOS TRANS R SOC LONDON [B] 272, 537607.Google Scholar
Ingham, J. K. 1970. The Upper Ordovician trilobites from the Cautley and Dent districts of Westmorland and Yorkshire. Part I. PALAEONTOGR SOC MONOGR 158.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, 288334.CrossRefGoogle Scholar
Lamont, A. 1941. Trinucleidae in Eire. ANN MAG NAT HIST [11]8, 438–69.CrossRefGoogle Scholar
M'Coy, F. 1849. On the classification of some British fossil Crustacea, with notices of new forms in the University Collection at Cambridge. ANN MAG NAT HIST [2], 4, 161–79, 330–5, 392–414.CrossRefGoogle Scholar
MacGregor, A. R. 1962. Upper Llandeilo trilobites from the Berwyn Hills, North Wales. PALAEONTOLOGY 5, 790816.Google Scholar
Murchison, R. I. 1839. The Silurian System, Part II, 579768. London: John Murray.Google Scholar
Portlock, J. E. 1837. In Larcom, T.Ordnance Survey of the County of Londonderry, Vol. 1, Memoir of the city and north western liberties of Londonderry: Parish of Templemore, 36. Dublin: Hodges and Smith.Google Scholar
Portlock, J. E. 1843. Report on the Geology of the County of Londonderry and Parts of Tyrone and Fermanagh. Dublin: A. Milliken.Google Scholar
Reed, F. R. C. 1895. New trilobites from the Bala Beds of Co. Waterford. GEOL MAG [4], 11, 4955.CrossRefGoogle Scholar
Reed, F. R. C. 1897. Appendix on the Fossils. In Gardiner, C. I. and Reynolds, S. H.An account of the Portraine inlier (Co. Dublin). Q J GEOL SOC LONDON 53, 535–9.Google Scholar
Reed, F. R. C. 1903. The Lower Palaeozoic trilobites of the Girvan district, Ayrshire. Part 1. PALAEONTOGR SOC MONOGR 148.Google Scholar
Reed, F. R. C. 1910. New fossils from the Dufton Shales. GEOL MAG [5], 7, 211–20.CrossRefGoogle Scholar
Reed, F. R. C. 1912. Sedgwick Museum Notes. Notes on the genus Trinucleus. Part I. GEOL MAG [5], 9, 346–53.CrossRefGoogle Scholar
Reed, F. R. C. 1914. The Lower Palaeozoic trilobites of Girvan. Supplement. PALAEONTOGR SOC MONOGR 156.Google Scholar
Reed, F. R. C. 1935. The Lower Palaeozoic trilobites of Girvan. Supplement No. 3. PALAEONTOGR SOC MONOGR 164.Google Scholar
Reed, F. R. C. 1952. Revision of certain Ordovician fossils from County Tyrone. PROC R IRISH ACAD [B] 55, 29136.Google Scholar
Salter, J. W. 1853. Figures and descriptions illustrative of British organic remains. MEM GEOL SURV UK Dec. VII, Plate VII, 18.Google Scholar
Salter, J. W. 1859. In Murchison, R. I.Siluria 3rd [2nd] edn. London: John Murray.Google Scholar
Salter, J. W. 1866. Appendix: On the fossils of North Wales. In Ramsay, A. C.The Geology of North Wales. MEM GEOL SURV U K 3, 239363.Google Scholar
Sammon, J. W. 1969. A nonlinear mapping for data structure analysis. IEEE TRANS COMPUTERS C18, 401–9.CrossRefGoogle Scholar
Stubblefield, C. J. 1967. Some results of a recent Geological Survey boring in Huntingdonshire. PROC GEOL SOC LONDON 1637, 35–8.Google Scholar
Stubblefield, C. J. & Whittington, H. B. 1956. Proposed use of the plenary powers to validate the generic names ‘Trinucleus’ Murchison, 1839, and ‘Tretaspis’ M'Coy, 1849 (Class Trilobita). BULL ZOOL NOMENCL 12, 4954.Google Scholar
Temple, J. T. & Tripp, R. P. 1979. An investigation of the Encrinurinae (Trilobita) by numerical taxonomie methods. TRANS R SOC EDINBURGH 70, 223–50.Google Scholar
Tunnicliff, S. P. 1978. Types of the Ordovician trilobites Celtencrinurus multisegmentatus (Portlock) and Cryptolithus latus Portlock. PALAEONTOLOGY 21, 455–8.Google Scholar
Tunnicliff, S. P. 1980. A catalogue of the Lower Palaeozoic Portlock Collection. Belfast: Ulster Museum.Google Scholar
Wade, A. 1911. The Llandovery and associated rocks of North-eastern Montgomeryshire. Q J GEOL SOC LONDON 67, 415–57.CrossRefGoogle Scholar
Whittard, W. F. 1955. The Ordovician trilobites of the Shelve inlier, West Shropshire. Part I. PALAEONTOGR SOC MONOGR 140.Google Scholar
Whittard, W. F. 1956. The Ordovician trilobites of the Shelve inlier, West Shropshire. Part II. PALAEONTOGR SOC MONOGR 4170.Google Scholar
Whittard, W. F. 1957. ‘Trinucleus’ primitivus from the south of France. SENCKENB LETHAEA 38, 267–74.Google Scholar
Whittard, W. F. 1958. The Ordovician trilobites of the Shelve inlier, West Shropshire. Part III. PALAEONTOGR SOC MONOGR 71116.Google Scholar
Whittard, W. F. 1966. The Ordovician trilobites of the Shelve inlier, West Shropshire. Part VIII. PALAEONTOGR SOC MONOGR 265306.Google Scholar
Whittington, H. B. 1966. Trilobites of the Henllan Ash, Arenig Series, Merioneth. BULL BR MUS NAT HIST [GEOL] 11, 489505.Google Scholar
Williams, A. 1948. The Lower Ordovician Cryptolithids of the Llandeilo district. GEOL MAG 85, 6588.CrossRefGoogle Scholar