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Trilobite abnormalities

Published online by Cambridge University Press:  03 November 2011

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

Abstract

There is abundant evidence of injury, teratology and pathological conditions in trilobites although it is commonly difficult to distinguish between their morphological results. Many injuries were probably sustained during moulting, with spines, bilamellar fringes and narrow gaps between dorsal exoskeleton and doublure being most vulnerable. Some injuries were the result of predaceous attack and provide important clues to the trophic structure of Palaeozoic communities. Many injuries show evidence of repair. Some supposedly teratological conditions, most notably the number of paradoxidid thoracic segments, are so common that they must be considered part of normal variation. Others represent genetic mutation or ontogenetic malfunction, the latter possibly externally induced. Undoubted pathological conditions are restricted to swellings and borings presumably caused by parasitic infestation.

Abnormalities affecting lateral areas are more common than those involving the rachis and glabella and this probably reflects both greater mortality when the axial region is involved, and greater vulnerability of peripheral regions to predaceous and moulting damage. The first explanation also accounts for the rarity of cephalic abnormalities compared to those of the pygidium.

Type
Life and environment of fossil forms
Copyright
Copyright © Royal Society of Edinburgh 1985

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References

Alberti, G. 1970. Trilobiten des jüngeren Siluriums sowie des Unter- und Mitteldevons. ABH SENCKENB NATURFORSCH GES 525, 1233.Google Scholar
Alpert, S. P. & Moore, J. N. 1975. Lower Cambrian trace fossil evidence for predation on trilobites. LETHAIA 8, 223–30.CrossRefGoogle Scholar
Bergström, J. 1973. Organization, life and systematics of trilobites. FOSSILS STRATA 2, 169.CrossRefGoogle Scholar
Bergström, J. & Levi-Setti, R. 1978. Phenotypic variation in the Middle Cambrian trilobite Paradoxides davidis SALTER at Manuels, S. E. Newfoundland. GEOL PALAEONTOL 12, 140.Google Scholar
Bohlin, B. 1960. Trilobites of the Genus Megistaspis from the Vaginatum Limestone of Scandinavia. BULL GEOL INST UNIV UPPS 38, 155205.Google Scholar
Boucot, A. J. 1981. Principles of Benthic Marine Paleoecology. New York: Academic Press.Google Scholar
Burling, L. D. 1917. Was the Lower Cambrian trilobite supreme? OTTAWA NAT 31, 77–9.Google Scholar
Campbell, K. S. W. 1967. Trilobites from the Henryhouse Formation, Oklahoma. BULL OKLAHOMA GEOL SURV 115, 168.Google Scholar
Cave, R. 1957. Salterolithus caractaci (Murchison) from Caradoc strata near Welshpool, Montgomeryshire. GEOL MAG 94, 281–90.CrossRefGoogle Scholar
Chatterton, B. D. E. 1971. Taxonomy and ontogeny of Siluro-Devonian trilobites from near Yass, New South Wales. PALAEONTOGR ABT A 137, 1108.Google Scholar
Chatterton, B. D. E. 1980. Ontogenetic studies of Middle Ordovician trilobites from the Esbataottine Formation, Mackenzie Mountains, Canada. PALAEONTOGR ABT A 171, 174.Google Scholar
Clarkson, E. N. K. 1969. On the schizochroal eyes of three species of Reedops (Trilobita, Phacopidae) from the Lower Devonian of Bohemia. TRANS R SOC EDINBURGH 68, 183205.CrossRefGoogle Scholar
Clarkson, E. N. K. 1979. Invertebrate Palaeontology and Evolution. London: George Allen & Unwin.Google Scholar
Conway, , Morris, S. 1981. Parasites and the fossil record. PARASITOLOGY 82, 489509.Google Scholar
Cowie, J. & McNamara, K. J. 1978. Olenellus (Trilobita) from the Lower Cambrian Strata of north-west Scotland. PALAEONTOLOGY 21, 615–34.Google Scholar
Crowson, R. A. 1981. The biology of the Coleoptera. London: Academic Press.Google Scholar
Dalingwater, J. E. 1975. Secondary microstructures in trilobite cuticles. FOSSILS STRATA 4, 151–4.CrossRefGoogle Scholar
Dean, W. T. 1960. The Ordovician trilobite faunas of south Shropshire. BULL BR MUS (NAT HIST) GEOL 4, 73143.Google Scholar
Dean, W. T. 1967. The correlation and trilobite fauna of the Bedinan Formation (Ordovician) in south-eastern Turkey. BULL BR MUS (NAT HIST) GEOL 15, 81123.Google Scholar
Eldredge, N. 1977. Trilobites and evolutionary patterns. In Hallam, A. (ed.) Patterns of evolution as illustrated by the fossil record, 305–32. Amsterdam: Elsevier.CrossRefGoogle Scholar
Erben, H. K. 1967. Bau der Segmente und der Randbestachelung im Pygidium der Scutelluidae (Tril.) NEUES JAHRB GEOL PALAONTOL ABH 129, 164.Google Scholar
Evitt, W. R. & Tripp, R. P. 1977. Silicifled middle Ordovician trilobites from the families Encrinuridae and Staurocephalidae. PALAEONTOGR ABT A 157, 109–74.Google Scholar
Fortey, R. A. 1975. The Ordovician Trilobites of Spitsbergen II. SKR NOR POLARINST 162, 1207.Google Scholar
Fortey, R. A. 1980. The Ordovician trilobites of Spitsbergen III. SKR NOR POLARINST 171, 1163.Google Scholar
Gould, S. J. 1980. Is a new and general theory of evolution emerging? PALEOBIOLOGY 6, 119–30.CrossRefGoogle Scholar
Gould, S. J. 1983. Hen's Teeth and Horse's Toes. New York: W. W. Norton.Google Scholar
Hahn, G. & Hahn, R. 1971. Revision von Griffithides (Bollandia) (Tril; Unter-Karbon). PALAEONTOGR ABT A 137, 109–51.Google Scholar
Hahn, G., Hahn, R. & Brauckmann, C. 1982. Die Trilobiten des belgischen Kohlenkalkes (Unter-Karbon) 4. Phillipsia. GEOL PALAEONTOL 16, 163–82.Google Scholar
Hall, J. & Clarke, J. M. 1888. Palaeontology: Trilobites and other Crustacea. GEOL SURV STATE NEW YORK 7, 1236.Google Scholar
Hammann, W. 1971. Die Placopariinae (Trilobita, Cheirurina, Ordovizium). SENCKENBERGIANA LETHAIA 52, 5375.Google Scholar
Harper, D. A. T. & Owen, A. W. 1984. The Caradoc brachiopod and trilobite fauna of the upper Kirkerud Group, Hadeland, Norway. GEOL PALAEONTOL 18, 2151.Google Scholar
Harrington, H. J. & Leanza, A. F. 1957. Ordovician trilobites of Argentina. DEPT GEOL UNIV KANSAS SPEC PUBL 1, 1276.Google Scholar
Henningsmoen, G. 1960. The Middle Ordovician of the Oslo Region, Norway, 13. Trilobites of the Family Asaphidae. NOR GEOL TIDSSKR 40, 203–57.Google Scholar
Henningsmoen, G. 1975. Moulting in trilobites. FOSSILS STRATA 4, 179200.CrossRefGoogle Scholar
Henry, J.-L. 1980. Trilobites ordoviciens du Massif Armoricain. MEM SOC GEOL MINER BRETAGNE 22, 1250.Google Scholar
Hessler, R. 1962. Secondary segmentation in the thorax of trilobites. J PALEONT 36, 1305–12.Google Scholar
Hewitt, R. A. & Watkins, R. 1980. Cephalopod ecology across a late Silurian shelf tract. NEUES JAHRB GEOL PALAONT ABH 160, 96117.Google Scholar
Holloway, D. J. 1980. Middle Silurian trilobites from Arkansas and Oklahoma, U.S.A. PALAEONTOGR ABT A 170, 185.Google Scholar
Holm, G. 1886. In Schmidt, F. Revision der ostbaltischen silurischen Trilobiten III. Illaeniden. MEM AKAD IMP SCI ST PETERSBURG (7), 33, (8), 1173.Google Scholar
Howells, Y. 1982. Scottish Silurian Trilobites. PALAEONTOGR SOC MONOGR.Google Scholar
Hughes, C. P. 1969. The Ordovician trilobite faunas of the Builth-Llandrindod Inlier, Central Wales, Part I. BULL BR MUS (NAT HIST) GEOL 18, 39103.Google 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, 117182.Google Scholar
Hughes, C. P., Ingham, J. K. & Addison, R. 1975. The morphology, classification and evolution of the Trinucleidae (Trilobita). PHILOS TRANS R SOC LONDON B272, 537607.Google Scholar
Hupé, P. 1953. Classification des trilobites. ANN PALEONTOL 39, 61169.Google Scholar
Ingham, J. K. 1968. British and Swedish Ordovician species of Cybeloides (Trilobita). SCOTT J GEOL 4, 300–16.CrossRefGoogle Scholar
Ingham, J. K. 1974. A monograph of the upper Ordovician trilobites from the Cautley and Dent districts of Westmorland and Yorkshire. Part 2. PALAEONTOGR SOC MONOGR.CrossRefGoogle Scholar
Isberg, O. 1917. Ein regeneriertes Trilobitenauge. GEOL FOREN STOCKH FORH 39, 593–6.CrossRefGoogle Scholar
Jell, P. A. 1975. Australian Middle Cambrian eodiscoids with a review of the superfamily. PALAEONTOGR ABT A 150, 197.Google Scholar
Kay, M. 1937. Stratigraphy of the Trenton Group. BULL GEOL SOC AM 48, 233302.CrossRefGoogle Scholar
Kraft, J. 1972. Type specimens of fossils in the West Bohemian Museum in Plzen and in the Regional Museum of Dr B. Horák in Rokycary. Part 1—Trilobita. FOLIA MUS RERUM NAT BOHEMIAE OCCIDENT (GEOL) 1, 112.Google Scholar
Lamont, A. 1952. Ecology and correlation of the Pentlandian—a new division of the Silurian System in Scotland. REP 17th INT GEOL CONGR 10, 2732.Google Scholar
Lamont, A. 1975. Cambrian trilobites from the Pass of Leny, Perthshire, Scotland. SCOTT J SCI 1, 199215.Google Scholar
Lane, P. D. 1971. British Cheiruridae (Trilobita). PALAEONTOGR SOC MONOGR.CrossRefGoogle Scholar
Lochman, C. 1936. New trilobite genera from the Bonneterre dolomite (Upper Cambrian) of Missouri. J PALEONTOL 10, 3543.Google Scholar
Lochman, C. 1941. A pathologic pygidium from the Upper Cambrian of Missouri. J PALEONTOL 15, 324–5.Google Scholar
Ludvigsen, R. 1977. Rapid repair of traumatic injury by an Ordovician trilobite. LETHAIA 10, 205–7.CrossRefGoogle Scholar
Ludvigsen, R. 1977a. The Ordovician trilobite Ceraurinus Barton in North America. J PALEONTOL 51, 959–72.Google Scholar
Ludvigsen, R. 1979. Fossils of Ontario Part I: The Trilobites. MISC PUBL R ONTARIO MUS LIFE SCI.Google Scholar
Ludvigsen, R. 1979a. A trilobite zonation of Middle Ordovician rocks, southwestern district of Mackenzie. BULL GEOL SURV CAN 312, 199.Google Scholar
Ludvigsen, R. 1979b. The Ordovician Trilobite Pseudogygites Kobayashi in Eastern and Arctic North America. LIFE SCI CONTRIB R ONTARIO MUS 120, 141.Google Scholar
Ludvigsen, R. & Westrop, S. R. 1983. Franconian Trilobites of New York State. MEM NEW YORK ST MUS 23, 183.Google Scholar
McNamara, K. J. & Rudkin, D. M. 1984. Techniques of trilobite exuviation. LETHAIA 17, 153–73.CrossRefGoogle Scholar
Miller, J. & Clarkson, E. N. K. 1980. The post–ecdysial development of the cuticle and the eye of the Devonian trilobite Phacops rana milleri Stewart, 1927. PHILOS TRANS R SOC LOND B288, 461–80.Google Scholar
Moore, R. C. (ed.) 1959. Treatise on Invertebrate Paleontology, Part 0, Arthropoda 1. Lawrence, Kansas: Geol. Soc. Am. & Univ. Kansas Press.Google Scholar
Neville, A. C. 1976. Animal Asymmetry. London: Edward Arnold.Google Scholar
Oehlert, D. P. 1895. Sur les Trincleus de l'Ouest de la France. BULL SOC GEOL FR 23.Google Scholar
Öpik, A. A. 1937. Trilobiten aus Estland. ACTA COMM UNIV TARTU (A) 32, 1163.Google Scholar
Öpik, A. A. 1958. The Cambrian trilobite Redlichia: organization and generic concept. BULL BUR MIN RES AUST 42, 138.Google Scholar
Öpik, A. A. 1961. The geology and palaeontology of the headwaters of the Burke Rivers, Queensland. BULL BUR MINER RESOUR AUST 53, 1249.Google Scholar
Öpik, A. A. 1967. The Mindyallan Fauna of North-western Queensland. BULL BUR MINER RESOUR AUST 74, 1404.Google Scholar
Ormiston, A. R. 1967. Lower and Middle Devonian trilobites of the Canadian Arctic Islands. BULL GEOL SURV CAN 153, 1148.Google Scholar
Osmolska, H. 1968. Brachymetopus McCoy (Trilobita) in the Carboniferous of Poland and the U.S.S.R. ACTA PALEONTOL POLON 13, 359–78.Google Scholar
Osmolska, H. 1970. Revision of non-cyrtosymboiinid trilobites from the Tournaisian-Namurian of Eurasia. PALAEONTOL POL 23, 1165.Google Scholar
Owen, A. W. 1980. An abnormal cranidium of the trilobite Calyptaulax norvegicus. NOR GEOL TIDSSKR 60, 87–8.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. The trilobite Mucronaspis in the uppermost Ordovician of the Oslo Region, Norway. NOR GEOL TIDSSKR 61, 271–9.Google Scholar
Owen, A. W. 1983. Abnormal cephalic fringes in the Trinucleidae and Harpetidae (Trilobita). In Briggs, D. E. G. & Lane, P. D. (eds) Trilobites and other early arthropods: papers in honour of Professor H. B. Whittington F.R.S. 241–7. SPEC PAP PALAEONTOL.Google Scholar
Owen, A. W. 1983a. The trinucleid trilobite Broeggerolithus in the Ordivician of Scandinavia. GEOL FOREN STOCKH FORH 105, 4953.CrossRefGoogle Scholar
Owen, A. W. & Bruton, D. L. 1980. Late Caradoc–early Ashgill trilobites from the Central Oslo Region, Norway. PALEONTOL CONTRIB UNIV OSLO 245, 163.Google Scholar
Owen, A. W. & Harper, D. A. T. 1982. The Middle Ordovician of the Oslo Region, Norway, 31. The upper Caradoc trilobites and brachiopods from Vestbråten, Ringerike. NOR GEOL TIDSSKR 62, 95120.Google Scholar
Palmer, A. R. 1958. Morphology and ontogeny of a Lower Cambrian ptychoparioid trilobite from Nevada. J PALEONTOL 32, 154–70.Google Scholar
Palmer, A. R. 1960. Trilobites of the Upper Cambrian Dunderberg Shale, Eureka District, Nevada. PROC PAP U S GEOL SURV 334–C, 53109.Google Scholar
Palmer, A. R. 1965. Trilobites of the Late Cambrian Pterocephaliid Biomere in the Great Basin, United States. PROF PAP U S GEOL SURV 494, 1105.Google Scholar
Palmer, A. R. 1968. Cambrian Trilobites of East-Central Alaska. PROF PAP U S GEOL SURV 559–B, 1115.Google Scholar
Piveteau, J. 1953. Traité de Paléontologie, III. Paris: Masson.Google Scholar
Pocock, K. J. 1970. The Emuellidae, a new family of trilobites from the Lower Cambrian of South Australia. PALAEONTOLOGY 13, 522–62.Google Scholar
Pocock, K. J. 1974. A unique case of teratology in triobite segmentation. LETHAIA 7, 63–6.CrossRefGoogle Scholar
Portlock, J. E. 1843. Report on the geology of the county of Londonderry and parts of Tyrone and Fermanagh. Dublin & London.Google Scholar
Prantl, F. & Přibyl, A. 1954. O. ceských zástupcích celedi Harpedidae (Hawle et Corda) (Trilobitae). ROZPR USTRED USTRAVU 18, 1170.Google Scholar
Přibyl, A. & Vaněk, J. 1969. Trilobites of the family Trinucleidae Hawle et Corda, 1847 from the Ordovician of Bohemia. SB GEOL VED PALAEONT 11, 85137.Google Scholar
Přibyl, A. & Vaněk, J. 1973 (for 1972). Zur Taxonomie und Biostratigraphie der Crotalocephaliden Trilobiten aus dem böhmischen Silur und Devon. SB NAR MUZ V PRAZE 28B 3792.Google Scholar
Přibyl, A. & Vaněk, J. 1981. Preliminary report on some new trilobites of the family Harpetidae Hawle et Corda. CAS PRO MIN GEOL 26, 187–93.Google Scholar
Přibyl, A. & Vaněk, J. (in press). A study of the morphology and phylogeny of the family Harpetidae Hawle et Corda (Trilobita). SB NAR MUZ V PRAZE.Google Scholar
Ramsköld, L. 1983. Silurian Cheirurid Trilobites from Gotland. PALAEONTOLOGY 26, 175210.Google Scholar
Ramsköld, L. 1984. Silurian Odontopleurid Trilobites from Gotland. PALAEONTOLOGY 27, 239–64.Google Scholar
Raymond, P. 1916. New and old Silurian Trilobites from south-eastern Wisconsin, with notes on the genera of the Illaenidae. BULL MUS COMP ZOOL HARVARD 60, 141.Google Scholar
Resser, C. E. 1939. The Spence Shale and its fauna. SMITHSON MISC COLLECT 97, 124.Google Scholar
Richter, R. & Richter, E. 1934. Missbildungen bei Scutellidae und konstruktive Konvergenzen. SENCKENBERGIANA 16, 155–60.Google Scholar
Ross, R. J. Jnr. 1951. Stratigraphy of the Garden City Formation in north-eastern Utah and its trilobite faunas. BULL PEABODY MUS NAT HIST YALE UNIV 6, 1161.Google Scholar
Ross, R. J. Jnr. 1957. Ordovician Fossils from Wells in the Williston Basin, Eastern Montana. BULL U S GEOL SURV 1021–M, 439510.Google Scholar
Rudkin, D. M. 1979. Healed injuries in Ogygopsis klotzi (Trilobita) from the Middle Cambrian of British Columbia. LIFE SCI OCC PAP R ONTARIO MUS 32, 18.Google Scholar
Rudkin, D. M. (in press). Exoskeletal abnormalities in four trilobites. CAN J EARTH SCI.Google Scholar
Ruedemann, R. & Howell, V. F. 1944. Impression of a worm on the test of a Cambrian Trilobite. J PALEONTOL 18, 96.Google Scholar
Rushton, A. W. A. 1967. The Upper Cambrian Trilobite Irvingella nuneatonensis (Sharman). PALAEONTOLOGY 10, 339–48.Google Scholar
Saito, K. 1934. Older Cambrian Trilobita and Conchostraca from north-western Korea. JPN J GEOL GEOG (TOKYO) 11, 211–37.Google Scholar
Schmidt, F. 1906. Revision der ostbaltischen silurischen Trilobiten. Abt. V, Leif IV, enthaltend die Gattung Megistaspis. MEM AKAD IMP SCI ST PETERSBURG (8), 19, 10.Google Scholar
Schrank, E. 1969. Odontopleuriden (Trilobiten) aus silurischen Geschieben. BER GEOL GES DDR (A) 14, 705–26.Google Scholar
Selwood, E. B. 1965. Dechenellid trilobites from the British Middle Devonian. BULL BR MUS (NAT HIST) GEOL 10, 317–33.Google Scholar
Shaw, F. C. 1968. Early Middle Ordovician Chazy Trilobites of New York. MEM NEW YORK STATE MUS NAT HIST 17, 1114.Google Scholar
Signor, P. W. & Brett, C. E. 1984. The mid-Palaeozoic precursor to the Mesozoic marine revolution. PALEOBIOLOGY 10, 229–45.CrossRefGoogle Scholar
Sinclair, G. W. 1947. Two examples of injury in Ordovician trilobites. AM J SCI 245, 250–57.CrossRefGoogle Scholar
Šnajdr, M. 1956 (for 1955). Trilobiti drabovských a letenských vrstev českého ordoviku. SB USTRED USTAVU GEOL 22, 477533.Google Scholar
Šnajdr, M. 1958. Několik nových rodů trilobitů z čeledě Scutelluidae. VESTN USTRED USTAVU GEOL 33, 177–84.Google Scholar
Šnajdr, M. 1960. Studie o čeledi Scutelluidae (Trilobitae). ROZPR USTRED USTAVU GEOL 26, 1263.Google Scholar
Šnajdr, M. 1978. Anomalous carpaces of Bohemian paradoxid trilobites. SB GEOL VED PALEONT 20, 131.Google Scholar
Šnajdr, M. 1978a. Pathological neoplasms in the fringe of Bohemoharpes (Trilobita). VESTN USTRED USTAVU GEOL 53, 4950.Google Scholar
Šnajdr, M. 1979. Two trinucleid trilobites with repair of traumatic injury. VESTN USTRED USTAVU GEOL 54, 4950.Google Scholar
Šnajdr, M. 1979a. Note on the regenerative ability of injured trilobites. VESTN USTRED USTAVU GEOL 54, 171–3.Google Scholar
Šnajdr, M. 1979b. Patologické exoskeletony dvou Ordovických trilobitů z Barrandienu. CAS NAR MUZ 148, 173–6.Google Scholar
Šnajdr, M. 1980. Bohemian Silurian and Devonian Proetidae (Trilobita). ROZPR USTRED USTAVU GEOL 45, 1324.Google Scholar
Šnajdr, M. 1981. Ontogeny of some representatives of the trilobite genus Scharyia. SB GEOL VED PALEONT 24, 735.Google Scholar
Šnajdr, M. 1981a. Bohemian Proetidae with malformed exoskeletons. SB GEOL VED PALEONT 24, 3761.Google Scholar
Størmer, L. 1931. Boring organisms in trilobite shells. NOR GEOL TIDSSKR 12, 539–9.Google Scholar
Størmer, L. 1980. Sculpture and microstructure of the exoskeleton in chasmopinid and phacopid trilobites. PALAEONTOLOGY 23, 237–71.Google Scholar
Strusz, D. L. 1980. The Encrinuridae and related trilobite families with a description of Silurian species from southeastern Australia. PALAEONTOGR ABT A 168, 168.Google Scholar
Suf, J. 1926. O českých Paradoxidech se zvláŠtním zřetelen k jejich vývoji. SB STAT GEOL USTAVU 6, 3168.Google Scholar
Tasch, P. 1980. Paleobiology of the Invertebrates: Data Retrieval from the Fossil Record, 2nd edn. New York. John Wiley.Google Scholar
Thomas, A. T. 1978. British Wenlock Trilobites. Part 1. PALAEONTOGR SOC MONOGR.CrossRefGoogle Scholar
Thomas, A. T. & Owens, R. M. 1978. A review of the trilobite family Aulacopleuridae. PALAEONTOLOGY 21, 6581.Google Scholar
Tjernvik, T. E. 1956. On the Early Ordovician of Sweden. Stratigraphy and Fauna. BULL GEOL INST UNIV UPPS 36, 106284.Google Scholar
Tripp, R. P. 1962. Trilobites from the ‘confinis’ flags (Ordovician) of the Girvan District, Ayrshire. TRANS R SOC EDINBURGH 65, 140.CrossRefGoogle Scholar
Tripp, R. P. 1967. Trilobites from the Upper Stinchar Limestone (Ordovician) of the Girvan District, Ayrshire. TRANS R SOC EDINBURGH 67, 4393.CrossRefGoogle Scholar
Vaněk, , 1970. Representatives of the family Scutelluidae Richter et Richter, 1955 (Trilobita) from the Devonian of Central Bohemia. VESTN USTRED USTAVU GEOL 45, 137–46.Google Scholar
Vorwald, G. 1982. Healed injuries in trilobites—evidence for a large Cambrian predator. GEOL SOC AM ABSTR PROGRAM 14(7), 639.Google Scholar
Walcott, C. D. 1883. Injury sustained by the Eye of a Trilobite at the time of the Moulting of the Shell. AM J SCI 62, 302.CrossRefGoogle Scholar
Wandås, B. T. G. 1984 (for 1983). The Middle Ordovician of the Oslo Region, Norway, 33. Trilobites from the lowermost part of the Ogygiocaris Series. NOR GEOL TIDSSKR 63, 211–67.Google Scholar
Warburg, E. 1925. The trilobites of the Leptaena Limestone in Dalarne. BULL GEOL INST UNIV UPPS 17, 1446.Google Scholar
Westergård, A. H. 1936. Paradoxides oelandicus beds of Öland. SVER GEOL UNDERS C394, 166.Google Scholar
Westergård, A. H. 1953. Non-Agnostidean trilobites of the Middle Cambrian of Sweden III. SVER GEOL UNDERS C526, 158.Google Scholar
Whittard, W. F. 1956. The Ordovician trilobites of the Shelve inlier, West Shropshire, Part 2. PALAEONTOGR SOC MONOGR.Google Scholar
Whittington, H. B. 1956. Type and Other Species of Odontopleuridae (Trilobita). J PALEONTOL 30, 504–20.Google Scholar
Whittington, H. B. 1956a. Silicified Middle Ordovician trilobites: the Odontopleuridae. BULL MUS COMP ZOOL HARVARD 114, 155288.Google Scholar
Whittington, H. B. 1966. A monograph of the Ordovician trilobites of the Bala area, Merioneth. Part. 3. PALAEONTOGR SOC MONOGR.CrossRefGoogle Scholar
Whittington, H. B. 1968. Cryptolithus (Trilobita); specific characters and occurrence in Ordovician of eastern North America. J PALEONTOL 42, 702–14.Google Scholar
Whittington, H. B. & Campbell, K. S. W. 1967. Silicified Silurian trilobites from Maine. BULL MUS COMP ZOOL HARVARD 135, 447–83.Google Scholar