Hostname: page-component-8448b6f56d-c47g7 Total loading time: 0 Render date: 2024-04-23T09:25:35.269Z Has data issue: false hasContentIssue false

Revision and subdivision of the polyphyletic ‘Leonaspis’ (Trilobita)

Published online by Cambridge University Press:  03 November 2011

Lars Ramsköld
Affiliation:
Sektionen för paleozoologi, Naturhistoriska Riksmuseet, Box 50007, S-104 05, Stockholm, Sweden.
Brian D. E. Chatterton
Affiliation:
Department of Geology, University of Alberta, 1–26 Earth Sciences Building, Edmonton, Alberta, Canada T6G 2E3.

Abstract

A phylogenetic analysis is performed on all species previously assigned to the odontopleurid trilobite genus Leonaspis. The PAUP analysis shows this genus, as conventionally defined, to be polyphyletic, composed of four groups of equal taxonomie rank. Leonaspis (s.s.) is here restricted to one of these groups only, a monophyletic set of species characterised by ‘four-spined’ pygidia (i.e. with four spines between the major border spines) and a thorax of nine segments. Kettneraspis is recognised for the largest of these four groups, and is composed of ‘two-spined’ species with nine thoracic segments. Leonaspis and Kettneraspis belong to the Odontopleurinae. A third group of previous ‘Leonaspis’ species constitute a new genus of the Acidaspidinae. Its species are characterised by being ‘four-spined’ and having ten thoracic segments. For these the new genus Exallaspis is erected, with type species E. bufo. A fourth group of ‘Leonaspis’ species, being ‘four-spined’ with nine thoracic segments, belongs to Eoleonaspis, an Ordovician odontopleurine genus. Leonaspis and Exallaspis are temporally and spatially non-overlapping, Leonaspis being exclusively Gondwanan post-Wenlock, whereas Exallaspis is restricted to areas north of the Rheic Ocean and ranges from basal Llandovery to Ludlow. Kettneraspis is pandemic. The condition of five epiborder spines and ten border spines on the free cheek is proposed as plesiomorphic for odontopleurids, and the border spines are shown to originate as two separate rows with alternating spines. A shift in position of the facial suture is shown to transfer the genal spine from the cranidium to the free cheek in Kettneraspis meraspides of degree 1 or 2, and the previously suggested co-occurrence of a fixigenal and librigenal spine in these stages is refuted. Earlier proposed dimorphism is rejected, and two mechanisms for reduction in the number of pygidial border spines are proposed. Kettneraspis reetae sp. nov. is described.

Type
Research Article
Copyright
Copyright © Royal Society of Edinburgh 1991

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

Adrain, J. M. & Chatterton, B. D. E. 1990. Odontopleura (Trilobita, Silurian), and a method of constrained congruency analysis. J PALEONTOL 64, 600–14.CrossRefGoogle Scholar
Alberti, G. K. B. 1960. Trilobiten aus den Tentaculitenschiefern (Devon) von Schaderthal (Ost-Thüringen). MITT GEOL STAATSINST HAMBURG 29, 109–26.Google Scholar
Alberti, G. K. B. 1967. Neue obersilurische sowie unter- und mitteldevonische Trilobiten aus Marokko, Deutschland und einigen anderen europäischen Gebieten. 2. SENCKENBERG LETH 48, 481509.Google Scholar
Alberti, G. K. B. 1969. Trilobiten des jüngeren Siluriums sowie des unter- und Mitteldevons. I. ABH SENCKENBERG NATURFORSCH GES 520, 1692.Google Scholar
Alberti, G. K. B. 1970. Trilobiten des jüngeren Siluriums sowie des Unter- und Mitteldevons. II. ABH SENCKENBERG NATURFORSCH GES 525, 1233.Google Scholar
Alberti, H. 1969. Trilobiten (Harpidae und Odontopleuridae) aus dem Devon des Harzes und des Rheinischen Schiefergebirges. GEOL JAHRBUCH 87, 361–82.Google Scholar
Angelin, N. P. 1854. Palaeontologia Scandinavica. I: Crustacea formationis transitions. Fase. 2, 2192, pls. 25–41. Lund.Google Scholar
Apollonov, M. K. 1980. Trilobita. In Apollonov, M. K., Bandaletov, S. M., & Nikitin, I. F. (eds) Granitsa ordovika i silura v Kazakhstane [The Ordovician-Silurian boundary in Kazakhstan], 86118. Akad. nauk Kazakh. SSR. Alma-Ata. [In Russian.]Google Scholar
Balashova, E. A. 1975. Trilobity kitaygorodskogo gorizonta Podolii. In Balashov, Z. G., Volgin, V. N. & Krymgolts, G. Ya. (eds) Fauna pogranitsnykh ordoviksko-siluriyskikh otlozheniy Podolii [The faunas of Ordovician-Silurian boundary beds of Podolia]. VOPROSY PALEONTOLOGII 7, 102123, 176–179. [In Russian.]Google Scholar
Barrande, J. 1846. Notice préliminaire sur le systéme Silurien et les trilobites de Bohême, i–vi, 197. Leipsic.Google Scholar
Barrande, J. 1852. Système Silurien du centre de la Bohême. Y partie. Recherches paléontologiques, 1. Crustacés, Trilobites, i–xxx, 1935. Prague and Paris.Google Scholar
Barrande, J. 1872. Système Silurien du centre de la Bohême. Y partie. Recherches paléontologiques, supplément au vol. 1, i–xxx, 1647. Prague and Paris.Google Scholar
Bishop, G. S. O. 1986. Early and Middle Silurian conodonts from midwestern New South Wales. COUR FORSCHUNGSINST SENCKENBERG 89, 1337.Google Scholar
Braniša, L. 1965. Los fosiles guias de Bolivia. BOLL SERV GEOL BOLIVIA 6, 1282.Google Scholar
Bruton, D. L. 1966a. A new odontopleurid trilobite genus from the Devonian of Bohemia. PALAEONTOL 9, 330–45.Google Scholar
Bruton, D. L. 1966b. A revision of the Swedish Ordovician Odontopleuridae (Trilobita). BULL GEOL INST UNIV UPPSALA 43, (8) 140.Google Scholar
Bruton, D. L. 1967. Silurian odontopleurid trilobites from Sweden, Estonia, and Latvia. PALAEONTOL 10, 214–44.Google Scholar
Bruton, D. L. 1968. A revision of the Odontopleuridae (Trilobita) from the Palaeozoic of Bohemia. SKRIFT NORSKE VIDENSK-AKAD OSLO. I. MAT.-NATURV. KLASSE: NY SERIE 25, 173.Google Scholar
Burmeister, H. 1843. Die Organisation der Trilobiten, aus ihren lebenden Verwandten entwickelt: nebst einer systematischen Übersicht aller zeither beschriebenen Arten. 1–147, 6 pls. Berlin.CrossRefGoogle Scholar
Campbell, K. S. W. 1977. Trilobites of the Haragán, Bois d'Arc and Frisco Formations (early Devonian), Arbuckle Mountains region, Oklahoma. OKLAHOMA GEOL SURV, BULL 123, 1227.Google Scholar
Castelnau, F. de 1843. Essai sur le Système Silurien de l'Amérique septentrionale, i–xv, 156 pp. Paris and Strasbourg.Google Scholar
Wen-tang, Chang 1974. [Silurian trilobites.] In Nanjing Institute of Geology and Palaeontology (ed.) [A handbook of stratigraphy and palaeontology in Southwest China.], 173–87. Beijing, Science Press, Academia Sinica. [In Chinese.]Google Scholar
Chatterton, B. D. E. 1971. Taxonomy and ontogeny of Siluro-Devonian trilobites from near Yass, New South Wales. PALAEONTOGR A137, 1108.Google Scholar
Chatterton, B. D. E. 1980. Ontogenetic studies of Middle Ordovician trilobites from the Esbataottine Formation, Mackenzie Mountains, Canada. PALAEONTOGR A171, 174.Google Scholar
Chatterton, B. D. E. & Campbell, K. S. W. 1980. Silurian trilobites from near Canberra and some related forms from the Yass Basin. PALAEONTOGR A167, 77119.Google Scholar
Chatterton, B. D. E., Johnson, B. D. & Campbell, K. S. W. 1979. Silicified Lower Devonian trilobites from New South Wales. PALAEONTOL 22, 799837.Google Scholar
Chatterton, B. D. E. & Perry, D. G. 1979. Acanthalomina Prantl & Přibyl, a valid subgenus of the trilobite genus Diacanthaspis. J PALEONTOL 53, 1327–42.Google Scholar
Chatterton, B. D. E. & Perry, D. G. 1983. Silicified Silurian odontopleurid trilobites from the Mackenzie Mountains. PALAEONTOGR CAN 1, 1126.Google Scholar
Chatterton, B. D. E., Siveter, D. J., Edgecombe, G. D. & Hunt, A. S. 1990. Larvae and relationships of the Calymenina. J PALEONTOL 64, 255–77.CrossRefGoogle Scholar
Kwan-yuan, Chen 1948. On the occurrence of the odontopleurid fauna in western Yunnan. NAT PEKING UNIV FIFTIETH ANNIV PAP, GEOL SER, 117–28.Google Scholar
Chlupáč, I. 1969. Revision of the Middle Devonian trilobites from Horní Benešov in the Nízký Jeseník Mts. (Moravia). SBORNIK GEOL VED, PALEONTOL 10, 67103.Google Scholar
Chlupáč, I. 1989. The stratigraphically latest trilobite of the Barrandian area. ČAS MINERALOGII GEOL 34, 319–22.Google Scholar
Churkin, M. Jr, 1961. Silurian trilobites from the Klamath Mountains, California. J PALEONTOL 35, 168–75.Google Scholar
Clarke, J. M. 1908. Early Devonic history of New York and eastern North America. MEM NEW YORK STATE MUS NAT HIST 9, (1), 1366.Google Scholar
Clarkson, E. N. K. 1969. A functional study of the Silurian odontopleurid trilobite Leonaspis deflexa (Lake). LETHAIA 2, 329–44.CrossRefGoogle Scholar
Clarkson, E. N. K. & Howells, Y. 1981. Upper Llandovery trilobites from the Pentland Hills, Scotland. PALAEONTOL 24, 507–36.Google 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. PALAEONTOL 18, 703–24.Google Scholar
Colless, D. H. 1985. On the status of outgroups in phylogenetics. SYST ZOOL 34, 364–6.CrossRefGoogle Scholar
Conrad, T. A. 1841. Description of new genera and species of organic remains. Crustacea. ANN REP PALAEONTOL STATE OF NEW YORK 5, 4857.Google Scholar
Cooper, G. A. 1930. Part II. New species from the Upper Ordovician of Percé. In Schuchert, C. & Cooper, G. A., Upper Ordovician and Lower Devonian stratigraphy and paleontology of Percé, Québec. AM J SCI 20, 265–88, 365–92.Google Scholar
Dalman, J. W. 1828. Nya svenska palaeader. K SVENSKA VETENSK-AKAD HANDL 1828, 134–8.Google Scholar
Dean, W. T. 1962. The trilobites of the Caradoc Series in the Cross Fell Inlier of northern England. BULL BRIT MUS NAT HIST (GEOL), 7, 67134.Google Scholar
Dean, W. T. 1974. The trilobites of the Chair of Kildare Limestone (Upper Ordovician) of eastern Ireland. Part 2. PALAEONTOGR SOC MONOGR 539, 6198.CrossRefGoogle Scholar
Degardin, J.-M. & Pillet, J. 1984. Nouveaux trilobites du Silurien des Pyrénées centrales espagnoles. ANN SOC GEOL NORD 103, 8392.Google Scholar
Edgecombe, G. D., Speyer, S. E. & Chatterton, B. D. E. 1988. Protaspid larvae and phylogenetics of encrinurid trilobites. J PALEONTOL 62, 779–99.Google Scholar
Emmrich, H. F. 1839. De trilobite. Dissertatio petrefactologica etc 156. Berlin.Google Scholar
Emmrich, H. F. 1844. Zur Naturgeschichte der Trilobiten. 128. Meiningen.Google Scholar
Etheridge, R. & Mitchell, J. 1896. The Silurian trilobites of New South Wales, with references to those of other parts of Australia. Part IV. The Odontopleuridae. PROC LINN SOC NEW SOUTH WALES 1896, (4), 694721.Google Scholar
Evitt, W. R. & Tripp, R. P. 1977. Silicified Middle Ordovician trilobites from trie families Encrinuridae and Staurocephalidae. PALAEONTOGR A157, 109–74.Google Scholar
Feist, R. 1977. Le Siluro-Devonien du Sud-Est de la Montagne Noire (Hérault, France). 251 pp. Unpublished Ph.D. thesis, Univ. of Montpellier.Google Scholar
Giebel, C. 1858. Die silurische Fauna des Unterharzes, nach Herren C. Bischofs Sammlung bearbeitet. ABH NATURWISS VER SACHSEN THÜRINGEN HALLE 1, 261332.Google Scholar
Haas, W. 1968. Trilobiten aus dem Silur und Devon von Bithynien (NW-Türkei). PALAEONTOGR A130, 60207.Google Scholar
Haas, W. 1969. Lower Devonian trilobites from central Nevada and northern Mexico. J PALEONTOL 43, 641–59.Google Scholar
Hall, J. 1847. Descriptions of the organic remains of the lower division of the New York system. PALAEONTOL NEW YORK 1, 1338, 87 pls.Google Scholar
Hall, J. 1859. Descriptions and figures of the organic remains of the Lower Helderberg group and the Oriskany Sandstone. NEW YORK STATE GEOL SURV, PALAEONTOL NEW YORK 3, part 1 (text), 1859; part 2 (plates), 1861; i–xii, 1–532, 120 pls.Google Scholar
Hall, J. & Clarke, J. M. 1888. Descriptions of the trilobites and other Crustacea of the Oriskany, Upper Helderberg, Hamilton, Portage, Chemung, and Catskill Groups. NEW YORK STATE GEOL SURV, PALAEONTOL NEW YORK 7, 1236.Google Scholar
Hawle, I. & Corda, A. J. C. 1847. Prodrom einer Monographie der böhmischen Trilobiten. 1176. Prague, J. G. Calve.Google Scholar
Helbert, G. J. 1985. Silurian trilobites from Scandinavia. 354 pp. Unpublished Ph.D. thesis, Univ of Keele.Google Scholar
Horný, R. & Basti, F. 1970. Type specimens of fossils in the National Museum of Prague. Volume 1. Trilobita. 1354. National Museum, Prague.Google Scholar
Howells, Y. 1982. Scottish Silurian trilobites. PALAEONTOGR SOC MONOGR 561, 176.Google Scholar
Lee-wen, Hsiang & Jin-lin, Zhang 1983. Trilobita. In [Palaeontological atlas of Northwest China. Xinjiang Province. Vol. 2. Upper Palaeozoic.] 534–55. Beijing: Geological Publishing House. [In Chinese.]Google Scholar
Jaanusson, V. 1956. On the trilobite genus Celmus Angelin, 1854. BULL GEOL INST UNIV UPPSALA 36, 3549.Google Scholar
Jahnke, H. 1971. Fauna und Alter der Erbslochgrauwacke (Brachiopoden und Trilobiten, Unter-Devon, Rheinisches Schiefergebirge und Harz). GÖTTINGER ARB GEOL PALÄONTOL 9, 1105.Google Scholar
Kielan, Z. 1960. Upper Ordovician trilobites from Poland and some related forms from Bohemia and Scandinavia. PALAEONTOL POLONICA 11 (for 1959), 1198.Google Scholar
Kobayashi, T. & Hamada, T. 1974. Silurian trilobites of Japan in comparison with Asian, Pacific and other faunas. SPEC PAP PALAEONTOL SOC JAPAN 18, i-viii, 1155.Google Scholar
Kozłowski, R., 1923. Fauna dévonienne de Bolivie. ANN PALEONTOLE 12, 1112.Google Scholar
Lake, P. 1896. The British Silurian species of Acidaspis. Q J GEOL SOC LONDON 52, 235–45.CrossRefGoogle Scholar
Lamont, A. 1948. Scottish dragons. QUARRY MANAGERS J 31, 531–5.Google Scholar
Lane, P. D. 1979. Llandovery trilobites from Washington Land, North Greenland. BULL GRÖNLANDS GEOL UNDERS0GELSE 131, 137.CrossRefGoogle Scholar
Shan-ji, Li 1978. Trilobita. In [Palaeontological atlas of southwest China. Sichuan Province. Vol. 1. Sinian to Devonian.], 179284. Beijing: Geological Publishing House. [In Chinese.]Google Scholar
Lespérance, P. J. 1968. Ordovician and Silurian trilobite faunas of the White Head Formation, Percé region, Québec. J PALEONTOL 42, 811–26.Google Scholar
Yen-hao, Lu, Wen-tang, Chang, Chao-ling, Chu, Yi-yuan, Chien, & Lee-wen, Hsiang 1965. [Trilobites of China] 2, 363766. Beijing: Science Press. [In Chinese.]Google Scholar
Ludvigsen, R. 1979. Fossils of Ontario. Part 1: The trilobites. R ONTARIO MUS LIFE SCI MISC PUBL, 196.Google Scholar
Ludvigsen, R. & Tripp, R. P. 1990. Silurian trilobites from the northern Yukon Territory R ONTARIO MUS LIFE SCI CONTRIB, 153, 158.Google Scholar
Lütke, F. 1965. Zur Kenntnis herzynischer Trilobiten aus dem Unter-und Mitteldevon des Harzes. PALAEONTOGR A124, 151236.Google Scholar
Maksimova, Z. A. 1960. Devonskie i kamennougol'nye trilobity Rudnogo Altaya. (Paleontologicheskoe obosnovanie stratigrafii paleozoya Rudnogo Altaya, 7). [Devonian and Carboniferous trilobites of the Rudniy Altai. (Palaeontological base for the Palaeozoic stratigraphy of the Rudniy Altai, 7)]. Altayskiy gornometallurg. nauch.-issled. Inst. Moskva: Akad. nauk Kazakh. SSR. 1122. [In Russian.]Google Scholar
Maksimova, Z. A. 1968. Srednepaleozoyskie trilobity tsentral'nogo Kazakhstana. [Middle Palaeozoic trilobites of central Kazakhstan.] Trudy Vses. nauch.-issled. geol. Inst. (VSEGEI) 165, 1206. [In Russian.]Google Scholar
Männil, R. 1982. Trilobite communities (Wenlock, East Baltic). In Kaljo, D. & Klaamann, E. (eds.), Communities and biozones in the Baltic Silurian, 5162. Eesti NSV teaduste akadeemia. Geoloogia Instituut. Tallinn, Valgus. [In Russian with English summary.]Google Scholar
Marek, L. 1952. Contribution to the stratigraphy and fauna of the uppermost part of the Králův Dvůr Shales (Ashgillian). SB USTŘED USTAV GEOL, PALEONTOL 19, 429–55.Google Scholar
Marr, J. E. & Nicholson, H. A. 1888. The Stockdale Shales. Q J GEOL SOC LONDON 44, 654732.CrossRefGoogle Scholar
Miesen, J. 1970. Trilobiten der Eifel. 172. Leverkusen: Sammlung Meisen.Google Scholar
Miesen, J. 1977. Die Trilobiten der Salmerwegschichten, sowie neue Schneckenfunde von Sötenich. 133. Leverkusen: Sammlung Miesen.Google Scholar
Mitchell, J. 1919. Some additional trilobites from New South Wales. PROC LINN SOC NEW SOUTH WALES 44, 850–56.Google Scholar
Moore, R. C. (ed.) 1959. Treatise on invertebrate palaeontology. Part O, Arthropoda 1. Geol. Soc. Amer, and Univ. Kansas Press, i–xix, 1560.Google Scholar
Morris, S. F. 1988. A review of British trilobites, including a synoptic revision of Salter's monograph. PALAEONTOGR SOC MONOGR 574, 1316.Google Scholar
Morzadec, P. 1969. Le Dévonien de la rive nord de la rivière de Faou (Finistère). Etude stratigraphique, étude de trilobites. BULL SOC GEOL MINERALOG BRETAGNE 1968, 158.Google Scholar
Morzadec, P. 1983. Trilobites du Dévonien (Emsien-Famennien) de la rade de Brest (Massif Armoricain). PALAEONTOGR A181, 103–84.Google Scholar
Murchison, R. I. 1839. The Silurian System, founded on geological researches in the counties of Salop, Hereford, Radnor, Montgomery, Caermarthen, Brecon, Pembroke, Monmouth, Gloucester, Worcester, and Stafford; with descriptions of the coal-fields and overlying formations, i–xxxii, 1768. London: John Murray.Google Scholar
Neben, W. & Krueger, H. H. 1979. Fossilien kambrischer, ordovizischer und silurischer Geschiebe. STARINGIA 5, 163.Google Scholar
Ormiston, A. R. 1967. Lower and Middle Devonian trilobites of the Canadian Arctic islands. BULL GEOL SURV CAN 153, 1148.Google Scholar
Ormiston, A. R. 1971. Lower Devonian trilobites from the Michelle Formation, Yukon Territory. BULL GEOL SURV CANADA, 192, 2743.Google Scholar
Patterson, C. 1982. Morphological characters and homology. In Joysey, K. A. & Friday, A. E. (eds.), Problems of Phylogenetic Reconstruction, 2174. London and New York: Academic Press.Google Scholar
Patterson, C. 1988. The impact of evolutionary theories on systematics. In Hawksworth, D. L. (ed.), Prospects in systematics, 5991. Oxford: Clarendon Press.Google Scholar
Perry, D. G. & Chatterton, B. D. E. 1976. Phacops and other trilobites from Emsian age beds of the Delorme Formation, Mackenzie Mountains, Northwest Territories. CAN J EARTH SCI 13, 1466–78.CrossRefGoogle Scholar
Perry, D. G. & Chatterton, B. D. E. 1977. Silurian (Wenlockian) trilobites from Baillie-Hamilton Island, Canadian Arctic Archipelago. CAN J EARTH SCI 14, 285317.CrossRefGoogle Scholar
Petrunina, Z. E. 1975. In: Repina, L. N., Petrunina, Z. E., & Khairullina, T. I., Trilobita. In: Stratigraphy and fauna of the Lower Paleozoic, of the northern submontane belt of Turkestan and Alai ridges (southern Tyan-Shan). Akademia nauk SSSR, sibirskoe otdelenie, minist, geol. UZSSR, trudy inst. geol. i geofiziki 278, 100248. [In Russian.]Google Scholar
Philip, G. M. 1962. The palaeontology and stratigraphy of the Siluro-Devonian sediments of the Tyers area, Gippsland, Victoria. PROC R SOC VICTORIA 75, 124246.Google Scholar
Poulsen, C. 1934. The Silurian faunas of North Greenland. I. The fauna of the Cape Schuchert Formation. MEDD GRÖNLAND 72, 2, (1), 146.Google Scholar
Prantl, F. & Přibyl, A. 1949. A study of the superfamily Odontopleuracea nov. superfam. (trilobites). ROZPRAVY ÚSTŘED ÚSTAV GEOL 12, 1221. [In Czech and English, with Russian summary.]Google Scholar
Prantl, F. & Vaněk, J. 1958. In Horný, R., Prantl, F. & Vaněk, J.: On the limit between the Wenlock and the Ludlow in the Barrandian. SB ÚSTŘED ÚSTAV GEOL, ODD PALEONT, 24 (for 1957), 217–78. [In Czech, with English summary.]Google Scholar
Přibyl, A. & Vaněk, J. 1962. Trilobitová fauna českého svrchního siluru (budnanu a lochkovu) a její biostratigrafický význam. SBORNIK NARODNIHO MUZEA V PRAZE 18, B, 2546. [In Czech.]Google Scholar
Přibyl, A. & Vaněk, J. 1965. Neue Trilobiten des böhmischen Ordoviziums. VĚSTNIK ÚSTŘEDNIHO ÚSTAVU GEOLOGICKÉHO 40, 277–82.Google Scholar
Přibyl, A. & Vaněk, J. 1966. Zur Kenntnis der Odontopleuridae-Trilobiten aus dem böhmischen Altpaláozoikum ACTA UNIV CAROLINAE, GEOL 4, 289304.Google Scholar
Přibyl, A. & Vaněk, J. & Hörbinger, F. 1986. New trilobites of the families Odontopleuridae, Lichidae and Raphiophoridae from the Silurian and Devonian of central Bohemia. ČAS MIN GEOL 31, 267–78.Google Scholar
Ramsköld, L. 1984. Silurian odontopleurid trilobites from Gotland. PALAEONTOL 27, 239–64.Google Scholar
Ramsköld, L. 1991a. Pattern and process in the evolution of the Odontopleuridae (Trilobita). The Selenopeltinae and Ceratocephalinae. TRANS R SOC EDINBURGH 82, 143–81.CrossRefGoogle Scholar
Ramsköld, L. 1991b. The perforated trilobite Laethoprusia gen. nov., and the phylogeny of Koneprusia and Isoprusia (Odontopleuridae). TRANS R SOC EDINBURGH 82, 125–41.CrossRefGoogle Scholar
Ramsköld, L. & Werdelin, L. 1991. The phylogeny and evolution of some phacopid trilobites. CLADISTICS 7, 2974.CrossRefGoogle Scholar
Reed, F. R. C. 1896. The fauna of the Keisley Limestone. 1. QUARTERLY J GEOL SOC LONDON 52, 407–37.CrossRefGoogle 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. Silurian fossils from Kashmir. REC GEOL SURV INDIA 42, 1633.Google Scholar
Reed, F. R. C. 1914. The Lower Palaeozoic trilobites of Girvan. Supplement. PALAEONTOGR SOC MONOGR, 156.Google Scholar
Reed, F. R. C. 1915. Supplementary memoir on new Ordovician and Silurian fossils from the Northern Shan States. MEM GEOL SURV INDIA, PALAEONTOL INDICA, 6, (1), 1123.Google Scholar
Reed, F. R. C. 1925. The classification of the Acidaspidae. GEOL MAG 62, 416–30.CrossRefGoogle Scholar
Reed, F. R. C. 1931. Additional new trilobites from Girvan. ANN MAG NAT HIST (10), 7, 97105.CrossRefGoogle Scholar
Richter, Reinhard 1863. Aus dem thüringischen Schiefergebirge. Z DEUTSCHEN GEOL GES 15, 659–76.Google Scholar
Richter, Rudolf 1909. Beiträge zur Kenntnis devonischer Trilobiten aus dem Rheinischen Schiefergebirge. 196. Marburg.Google Scholar
Richter, R. & Richter, E. 1917. Über die Einteilung der Familie Acidaspidae und über einige ihrer devonischen Vertreter. ZENTRALBL MINERALOG, GEOL PALÄONTOL 1917, 462–72.Google Scholar
Richter, R. & Richter, E. 1918. Von unseren Trilobiten, II. BER SENCKENB NATURFORSCH GES 47, 123–31.Google Scholar
Richter, R. & Richter, E. 1926. Die Trilobiten des Oberdevons. Beiträge zur Kenntnis devonischer Trilobiten. IV. ABH PREUSS GEOL LANDESANST 99, 1314.Google Scholar
Richter, R. & Richter, E. 1930. Neue Hörner-Trilobiten in unserer Schausammlung. NATUR UND MUSEUM 60, 3145.Google Scholar
Richter, R. & Richter, E. 1949. Die trilobiten des Erdbach Zone (Kulm) in Rheinischen Schiefergebirge und im Harz, 1. Die Gattung Phillibole. SENCKENBERGIANA 30, 6394.Google Scholar
Richter, R. & Richter, E. 1952. Die Typen von Proetus tenuimargo und Leonaspis aries. SENCKENBERGIANA 33, 109–13.Google Scholar
Roemer, F. A. 1843. Die Versteinerungen des Harzgebirges, i–xx, 140, 12 pls. Hannover: Hahn.Google Scholar
Roemer, F. A. 1852. Beiträge zur geologischen Kenntnis des nordwestlichen Harzgebirges. 2. PALAEONTOGR 3, 67111.Google Scholar
Ross, R. J. 1979. Additional trilobites from the Ordovician of Kentucky. UNITED STATES GEOL SURV PROFESSIONAL PAPER 1066-D, 113.Google Scholar
Salter, J. W. 1853. Figures and descriptions illustrative of British organic remains. MEM GEOL SURV UNITED KINGDOM, DECADE 7, 10 pls.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
Sanderson, M. J. & Donoghue, M. J. 1989. Patterns of variation in levels of homoplasy. EVOLUTION 43, 1781–95.CrossRefGoogle ScholarPubMed
Schöning, H. 1986. Larvalstadien von Trilobiten aus einem Geschiebe des ‘grünlich-grauen Graptolithengesteins’ (Mittleres Silur). OSNABRÜCKER NATURWISS MITT 12, 6185.Google Scholar
Schrank, E. 1969. Odontopleuriden (Trilobita) aus silurischen Geschieben. BER DEUTSCH GESELL GEOL WISS, (A), GEOL PALÄONTOL 14, 705–26.Google Scholar
Scotese, C. R. & McKerrow, W. S. 1990. Revised world maps and introduction. In McKerrow, W. S. & Scotese, C. R. (eds), Palaeozoic palaeogeography and biogeography, 121. [Geological Society Memoir 12]. London: Geological Society.Google Scholar
Shaw, F. C. 1968. Early Middle Ordovician Chazy trilobites of New York. NEW YORK STATE MUS SCI SERV MEM 17, 1163.Google Scholar
Xin-fu, Sheng 1974. [Subdivision and correlation of the Ordovician System in China.] 1153. Beijing: Geological Publishing House. [In Chinese.]Google Scholar
Siveter, D. J. 1989. Silurian trilobites from the Annascaul inlier, Dingle Peninsula, Ireland. PALAEONTOL 32, 109–61.Google Scholar
Smeenk, Z. 1983. Devonian trilobites of the southern Cantabrian Mountains (northern Spain) with a systematic description of the Asteropyginae. LEIDSE GEOL MEDED 52, 383511.Google Scholar
Šnajdr, M. 1975. New Trilobita from the Llandovery at Hýskov in the Beroun area, central Bohemia. VESTN ÚSTŘED ÚSTAV GEOL 50, 311–16.Google Scholar
Šnajdr, M. 1978. The Llandoverian trilobites from Hýskov (Barrandian area). SB GEOL VED, PALEONTOL 21, 747.Google Scholar
Šnajdr, M. 1983. New Silurian trilobites from Bohemia. VESTN ÚSTřED ÚSTAV GEOL 58, 175–8.Google Scholar
Šnajdr, M. 1984. Bohemian Ordovician Odontopleuridae (Trilobita). SB GEOL VED, PALEONTOL 26, 4782.Google Scholar
Šnajdr, M. 1984b. Revision of the trilobite type material of I. Hawle and A. J. C. Corda, 1847. SB NAR MUZ V PRAZE, ŘADA B39 (for 1983), 129212.Google Scholar
Šnajdr, M. 1984c. Ivanopleura and Borkopleura, new odontopleurid genera from the Bohemian Silurian. VESTN ÚSTŘED ÚSTAV GEOL 59, 4952.Google Scholar
Šnajdr, M. 1986. Bohemian representatives of the trilobite genera Orphanaspis, Selenopeltoides and Taemasaspis (Odontopleuridae). ČAS NAR MUZ V PRAZE 153 (for 1984), 212–16.Google Scholar
Speyer, S. E. & Chatterton, B. D. E. 1989. Trilobite larvae and larval ecology. HISTORICAL BIOL 3, 2760.CrossRefGoogle Scholar
Steinmann, G. 1912. In Steinmann, G. & Hoek, H., Das, Silur und Cambrium des Hochlandes von, Bolivia und ihre, Fauna[ Steinmann, G., Beiträge zur Geologie und Paläontologie von Südamerica, 18]. NEUES JAHRB MINERALOG, GEOL, PALÄONTOL, BEIL 34, 176252.Google Scholar
Strauch, F. 1990. Fossilgrabung in Bolivien. PALÄONTOL AKTUELL 21, 41.Google Scholar
Strnad, V. 1957. O devonských trilobitech z Horního Benešova. SB ÚSTŘED ÚSTAV GEOL 23 (for 1956), 433–73.Google Scholar
Swartz, F. M. 1925. The Devonian fauna of Bolivia. JOHNS HOPKINS UNIV STUD GEOL 6, 2968.Google Scholar
Temple, J. T. 1970. The Lower Llandovery brachipods and trilobites from Ffridd Mathrafal, near Meifod, Montgomeryshire. PALAEONTOGR SOC MONOGR 527, 176.Google Scholar
Thomas, A. T. 1977. Acidaspis coronata Salter, 1853 (Trilobita): proposed conservation under the plenary powers. BULL ZOOL NOMENCL 34, 92–3.Google Scholar
Thomas, A. T. 1981. British Wenlock trilobites. 2. PALAEONTOGR SOC MONOGR 559, 5798.Google Scholar
Thomas, A. T., Owens, R. M., & Rushton, A. W. A. 1984. Trilobites in British stratigraphy. SPEC REP GEOL SOC LONDON 16, 178.Google Scholar
Thomas, A. T. & Holloway, D. J. 1988. Classification and phylogeny of the trilobite order Lichida. PHIL TRANS R SOC LONDON, B321, 179262.Google Scholar
Thomson, C., Wyville, 1857. On some species of Acidaspis from the Lower Silurian beds of the south of Scotland. Q J GEOL SOC LONDON 13, 206–10.CrossRefGoogle Scholar
Tripp, R. P. & Howells, Y. 1981. Catalogue of the described, figured and cited Ordovician and Silurian trilobites from the Girvan district, Scotland, in the British Museum (Natural History) 1–6, 2 fiches. London: British Museum (Natural History).Google Scholar
Troedson, G. T. 1918. Om Skånes brachiopodskiffer. MEDD FRAN LUNDS GEOL FÅLT, B10, 1110. [with English summary.]Google Scholar
Van Valen, L. 1982. Homology and causes. J MORPHOLOGY 173, 305–12.CrossRefGoogle ScholarPubMed
Waisfeld, B. G., Toro, B. A., & Brussa, E. D. 1988. Trilobitos silúricos de la Formation Los Espejos, sector occidental del Cerro del Fuerte, Precordillera de San Juan, Argentina. AMEGHINIANA 25, 305–20.Google Scholar
Xao-feng, Wang, Qing-luan, Zeng, Tian-mei, Zhou, Shi-zhao, Ni, Guang-hong, Xu, Quan-ying, Sun, Zhi-hong, Li, Li-wen, Xiang, & Cai-gen, Lai 1983. Latest Ordovician and earliest Silurian faunas from the eastern Yangtze Gorges, China, with comments on Ordovician-Silurian boundary. BULL YICHANG INST GEOL MIN RESOURCES, CHINESE ACAD GEOL SCI 6, 95163. [In Chinese and English.]Google Scholar
Weller, S. 1907. The paleontology of the Niagarán Limestone in the Chicago area. The Trilobita. BULL CHICAGO ACAD SCI 4, (2), 163281.Google Scholar
Whittard, W. F. 1938. The Upper Valentian trilobite fauna of Shropshire. ANN MAG NAT HIST (11) 1, 85140.CrossRefGoogle Scholar
Whittington, H. B. 1941. Silicified Trenton trilobites. J PALEONTOL 15, 492522.Google Scholar
Whittington, H. B. 1956a. Silicified Middle Ordovician trilobites: the Odontopleuridae. BULL MUS COMP ZOO 114, 155288.Google Scholar
Whittington, H. B. 1956b. Type and other species of Odontopleuridae. J PALEONTOL 30, 504–20.Google Scholar
Whittington, H. B. 1956c. Proposed use of the plenary powers to suppress certain nomina dubia and thus to validate the specific name tuberculatus as used in the combination Acidaspis tuberculatusGoogle Scholar
Hall, (J. W.) in 1859 and, by suppressing the generic name Acanthaloma Conrad, 1840, to provide an assured basis for the generic name LeonaspisGoogle Scholar
Richter, (R.) & Richter, (E.), 1917 (Class Trilobita). BULL ZOOL NOMENCL 12, 22–6.Google Scholar
Whittington, H. B. 1957. The ontogeny of trilobites. BIOL REV 32, 421–69.CrossRefGoogle Scholar
Whittington, H. B. 1966. Phylogeny and distribution of Ordovician trilobites. J. PALEONTOL 40, 696737.Google Scholar
Whittington, H. B. & Campbell, K. S. W. 1967. Silicified Silurian trilobites from Maine. BULL MUS COMP ZOOL 135, 447–83.Google Scholar
Whittington, H. B. & Evitt, W. R. 1954. Silicified Middle Ordovician trilobites. GEOL SOC AM, MEM 59, 1137.Google Scholar
Wolfart, R. 1968. Die Trilobiten aus dem Devon Boliviens und ihre Bedeutung für Stratigraphie und Tiergeographie. BEIHEFTE GEOL JAHRBUCH 74, 5201.Google Scholar
Li-wen, Xiang & Tian-mei, Zhou 1983. [Trilobites] In Wang Xao-feng, Zeng Qing-luan, Zhou Tian-mei, Ni Shi-zhao, Xu Guang-hong, Sun Quan-ying, Li Zhi-hong, Xiang Li-wen, & Lai Cai-gen, Latest Ordovician and earliest Silurian faunas from the eastern Yangtze Gorges, China, with comments on Ordovician-Silurian boundary. BULL YICHANG INST GEOL MIN RESOURCES, CHINESE ACAD GEOL SCI 6, 95163. [In Chinese and English.]Google Scholar
Yon-gen, Yi 1978. Trilobites. In [Sinian to Permian stratigraphy and palaeontology in the Xiadong area], 265–9. Beijing: Geological Publishing House. [In Chinese.]Google Scholar
Wen-tang, Zhang & Xian-song, Meng 1986. Silurian trilobites from Xichuan, Henan. ACTA PALAEONTOL SINICA 25, 507–15. [In Chinese, with English summary.]Google Scholar
Tian-mei, Zhou 1977. Trilobita. In [Palaeontological atlas of central and south China. 2. Late Palaeozoic], 586–97. Beijing: Geological Publishing House. [In Chinese.]Google Scholar