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Vincular furrows in some Early Silurian and Devonian Phacopidae (Trilobita), predominantly from North America

Published online by Cambridge University Press:  20 May 2016

Pierre J. Lespérance*
Affiliation:
Département de géologie, Université de Montréal, C. P. 6128, Montréal, Québec H3C 3J7, Canada

Abstract

The vincular furrow morphology of 19 species of Phacopidae is critically examined. The anterior part of the vincular furrow is much less variable than the posterior part of the vincular furrow, but it can be absent, shallow, deep, or have a slightly ventrally elongated boss. The posterior part of the vincular furrow can have pleurovincular pits (for reception of the thoracic pleural tip processes) or indentations for these processes, plus bounding walls that are variably indented laterally and very variable in vertical elongation. The functional morphology of the various elements of the vincular furrow is best explained by a paradigm of resistance to lateral shearing.

All elements of the vincular furrow in Devonian taxa had already appeared in the Early Silurian, but Early Silurian taxa are richer in diversity of elements. Some Devonian subspecies, essentially based on dorsal morphologies, show distinctly different vincular furrows. Cluster analysis of the data gathered on the vincular furrow complexes regroups the distinctly different Devonian subspecies and some Silurian subgenera. Other vincular furrows within the Phacopidae suggest that Reedops is near the Phacops logani complex and that the Phacopidellinae is a valid subfamily, but formal emendations within the family are not suggested because of incomplete data, notably on our knowledge of the distribution of vincular furrows. The use of the widely conceived genus Phacops Emmrich, 1839, over more recently described taxa such as Paciphacops Maximova, 1972, is presently favored, as this reflects more clearly current understanding of the systematics within the family Phacopidae.

Primary types of the North American taxa Phacops cristata, P. cristata gaspensis, and Acernaspis (Acernaspis) orestes are critically reviewed; significant changes of previous interpretations are suggested. Phacops cristata vitrea n. subsp. is erected. Thoracic pleural tip processes and anterolateral ventral pygidial processes are described in detail within Phacops rana rana and Acernaspis (Acernaspis) orestes. A pathological specimen of Phacops rana rana, with an injured eye, demonstrates that the individual did not revert to a primitive type of lens packing.

Type
Research Article
Copyright
Copyright © The Paleontological Society 

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References

Alberti, H. 1965. Reedops Rud. & E. Richter 1925 aus dem Rheinischen Schiefergebirge (Kellerwald) und Harz (Trilobitae, Unter- bis Mitteldevon). Fortschritte in der Geologie von Rheinland und West-falen, 9:97118.Google Scholar
Ayrton, W. G., Berry, W. B. N., Boucot, A. J., Lajoie, J., Lespérance, P. J., Pavlides, L., and Skidmore, W. B. 1969. Lower Llandovery of the Northern Appalachians and adjacent regions. Geological Society of America Bulletin, 80:459483.Google Scholar
Babcock, L. E., and Speyer, S. E. 1987. Enrolled trilobites from the Alden Pyrite Bed, Ledyard Shale (Middle Devonian) of Western New York. Journal of Paleontology, 61:539548.Google Scholar
Billings, E. 1857. Report for the year 1856, of E. Billings, Esq., palaeontologist, addressed to Sir William E. Logan, provincial geologist, p. 247345. In Geological Survey of Canada Report of Progress for the years 1853–54–55–56, Toronto.Google Scholar
Billings, E. 1860. Description of some new species of fossils from the Lower and Middle Silurian rocks of Canada. Canadian Naturalist and Geologist, 5:4969.Google Scholar
Billings, E. 1866. Catalogue of the fossils of the Anticosti Group with descriptions of some of the species, p. 2972. In Catalogues of the Silurian Fossils of the Island of Anticosti, with Descriptions of Some New Genera and Species. Geological Survey of Canada, Montreal.CrossRefGoogle Scholar
Bolton, T. E. 1966. Catalogue of Type Invertebrate Fossils by the Geological Survey of Canada. Vol. III. Geological Survey of Canada, 203 p.Google Scholar
Bolton, T. E. 1972. Geological map and notes on the Ordovician and Silurian litho- and biostratigraphy, Anticosti Island, Quebec. Geological Survey of Canada Paper 71-19, 45 p.Google Scholar
Bolton, T. E. 1981. Ordovician and Silurian biostratigraphy, Anticosti Island, Québec, p. 4159. In Lespérance, P. J. (ed.), Field meeting, Anticosti-Gaspé, Québec, 1981. International Union of Geological Sciences (IUGS) and Subcommission on Silurian Stratigraphy, Ordovician–Silurian Boundary Working Group, II, Stratigraphy and Paleontology. Département de géologie, Université de Montréal, Montréal.Google Scholar
Bronn, H. 1825. Ueber zwei neue Trilobiten-Arten zum Calymene-Geschlecte gehörig. Zeitschrift fuer Mineralogie [herausgegeben von K. C. Ritter von Leonhard], Jahrgang 1825(4):317321, Tafel 2, Frankfurt am Main (fide Struve, 1970).Google Scholar
Burton, C. J., and Eldredge, N. 1974. Two new subspecies of Phacops rana [Trilobita] from the Middle Devonian of North-West Africa. Palaeontology, 17:349363.Google Scholar
Campbell, K. S. W. 1967. Henryhouse trilobites. Bulletin of the Oklahoma Geological Survey 115, 68 p.Google Scholar
Campbell, K. S. W. 1975. Cladism and phacopid trilobites. Alcheringa, 1:8796.CrossRefGoogle Scholar
Campbell, K. S. W. 1977. Trilobites of the Haragan, Bois d'Arc and Frisco Formations (Early Devonian), Arbuckle Mountains Region, Oklahoma. Bulletin of the Oklahoma Geological Survey 123, 227 p.Google Scholar
Chlupáč, I. 1977. The phacopid trilobites of the Silurian and Devonian of Czechoslovakia. Rozpravy Ústredního ústavu geologického 43, 172 p.Google Scholar
Clarke, J. M. 1892. List of the original and illustrated specimens in the palaeontological collections, Pt. I, Crustacea, p. 57121. In (Eleventh) Annual Report of the State Geologist (for 1891). State of New York, 65, Albany.Google Scholar
Clarke, J. M. 1907. Some new Devonic fossils, p. 153292. In Geological Papers. New York State Museum Bulletin 107 (Geology 12) [New York State Education Department Bulletin 401].Google Scholar
Clarke, J. M. 1908. Early Devonic history of New York and Eastern North America (Part I). New York State Museum Memoir 9, 366 p.Google Scholar
Clarke, J. M., and Ruedemann, R. 1903. Catalogue of type specimens of Paleozoic fossils in New York State Museum. New York State Museum Bulletin 65 (Paleontology 8) [University of the State of New York Bulletin 284], 847 p.Google Scholar
Clarkson, E. N. K. 1966. The life attitude of the Silurian trilobite Phacops musheni Salter 1864. Scottish Journal of Geology, 2:7683.Google Scholar
Clarkson, E. N. K. 1971. On the early schizochroal eyes of Ormathops (Trilobita, Zeliszkellinae), p. 5163. In Colloque Ordovicien–Silurien. Mémoires du Bureau de Recherches Géologiques et Minières, 73.Google Scholar
Clarkson, E. N. K., and Henry, J.-L. 1973. Structures coaptatives et enroulement chez quelques Trilobites ordoviciens et siluriens. Lethaia, 6:105132.Google Scholar
Clarkson, E. N. K., Eldredge, N., and Henry, J.-L. 1977. Some Phacopina (Trilobita) from the Silurian of Scotland. Palaeontology, 20:119142.Google Scholar
Delo, D. M. 1940. Phacopid trilobites of North America. Geological Society of America Special Papers 29, 135 p.Google Scholar
Destombes, J., and Henry, J.-L. 1987. Trilobites Calmoniidae de l'Ordovicien supérieur du Maroc et les origines de la Province Malvino-Cafre. Lethaia, 20:129139.CrossRefGoogle Scholar
Eldredge, N. 1972. Systematics and evolution of Phacops rana (Green, 1832) and Phacops iowensis Delo, 1935 (Trilobita) from the Middle Devonian of North America. Bulletin of the American Museum of Natural History, 147:45113.Google Scholar
Eldredge, N. 1973. Systematics of Lower and lower Middle Devonian species of the trilobite Phacops Emmrich in North America. Bulletin of the American Museum of Natural History, 151:285337.Google Scholar
Eldredge, N., and Braniša, L. 1980. Calmoniid trilobites of the Lower Devonian Scaphiocoelia Zone of Bolivia, with remarks on related species. Bulletin of the American Museum of Natural History, 165:181290.Google Scholar
Emmrich, H. F. 1839. Trilobitis. Dissertatio petrefactologica quam concensu et auctoritate emplissimi philosophorum ordinis. Berlin, 56p. [fide Delo, 1940].Google Scholar
Green, J. 1832. Monograph of the Trilobites of North America: With Coloured Models of the Species. Joseph Brano, Philadelphia, 94 p.Google Scholar
Hall, J. 1859. Palaeontology: Vol. III. Containing Descriptions and Figures of the Organic Remains of the Lower Helderberg Group and the Oriskany Sandstone. 1855–1859. Pt. I: Text, 533 p. In Natural History of New York. Geological Survey of New York, Albany.Google Scholar
Hall, J. 1861. Palaeontology: Vol. III. Containing Descriptions and Figures of the Organic Remains of the Lower Helderberg Group and the Oriskany Sandstone. 1855–1859. Pt. II: Plates, 120 pls. In Natural History of New York. Geological Survey of New York, Albany.Google Scholar
Hall, J. 1862. Preliminary notice of the trilobites and other Crustacea of the Upper Helderberg, Hamilton and Chemung Groups, p. 82113, 197. In Fifteenth annual report of the Regents of the University of the State of New York, on the condition of the State Cabinet of Natural History, and the historical and antiquarian collection annexed thereto, Albany.Google Scholar
Hall, J. 1876. Illustrations of Devonian fossils: Gasteropoda, Pteropoda, Cephalopoda, Crustacea and Corals of the Upper Helderberg, Hamilton and Chemung Groups. Geological Survey of the State of New York, Palaeontology, 7p., pls. 1–13, 16–133, Albany.Google Scholar
Hall, J., and Clarke, J. M. 1888. Palaeontology: Vol. VII. Text and Plates—Containing Descriptions of the Trilobites and Other Crustacea of the Orkiskany, Upper Helderberg, Hamilton, Portage, Chemung and Catskill Groups, 236p., 36 pls. [Bound with Vol. V, Pt. II, supplement]. Geological Survey of the State of New York, Albany.Google Scholar
Hammann, W. 1974. Phacopina und Cheirurina (Trilobita) aus dem Ordovizium von Spanien. Senckenbergiana Lethaea, 55:1151.Google Scholar
Hammann, W. 1983. Calymenacea (Trilobita) aus dem Ordovizium von Spanien; ihre Biostratigraphie, Ökologie und Systematik, Abhandlungen der Senckenbergischen Naturforschenden Gesellschaft 542, 177 p.Google Scholar
Hammann, W. 1985. Life habit and enrolment (sic) in Calymenacea (Trilobita) and their significance for classification. Transactions of the Royal Society of Edinburgh, 76:307318.Google Scholar
Hawle, I., and Corda, A. J. 1847. Prodrom einer Monographie der böhmishen Trilobiten. Abhandlungen Böhmishen Gesellschaft Wissenschaften Prague, 5:117292.Google Scholar
Henry, J.-L. 1980. Trilobites ordoviciens du Massif Armoricain. Mémoire de la Société géologique et minéralogique de Bretagne, 22, 254 p.Google Scholar
Henry, J.-L. 1984. Analyse cladistique et Trilobites: un point de vue. Lethaia, 17:6166.Google Scholar
Henry, J.-L. 1985. New information on the coaptative devices in the Ordovician trilobites Placoparia and Crozonaspis, and its significance for their classification and phylogeny. Transactions of the Royal Society of Edinburgh, 76:319324.Google Scholar
Henry, J.-L., and Nion, J. 1970. Nouvelles observations sur quelques Zeliszkellinae et Phacopidellinae de l'Ordovicien de Bretagne. Lethaia, 3:213224.Google Scholar
Kilfoyle, C. F. 1954. Catalog of type specimens of fossils in the New York State Museum. Supplement 4. New York State Museum Bulletin 348, 719 p.Google Scholar
Lespérance, P. J. 1968. Ordovician and Silurian trilobite faunas of the White Head Formation, Percé region, Québec. Journal of Paleontology, 42:811826.Google Scholar
Lespérance, P. J. 1980. Calcaires Supérieurs de Gaspé: les aires types et le prolongement ouest. Ministère de l'Energie et des Ressources [du Québec], DPV-595, 79 p.Google Scholar
Lespérance, P. J. 1984. Vincular furrows in some Early Silurian Phacopidae (Trilobita) from Canada. Abstracts 27th International Geological Congress, Moscow, 1:283284.Google Scholar
Lespérance, P. J. 1988. Trilobites, p. 359376. In Cocks, L. R. M. and Rickards, R. B. (eds.), A Global Analysis of the Ordovician–Silurian Boundary. British Museum (Natural History), Geology Series, 43.Google Scholar
Lespérance, P. J. 1990. Cluster analysis of previously described communities from the Ludlow of the Welsh Borderland. Palaeontology, 33:209224.Google Scholar
Lespérance, P. J., and Letendre, J. 1981. Phacopid trilobites of the Anticostian Series of Anticosti Island and of the Matapédia Group in Gaspé (Québec), p. 197209. In Lespérance, P. J. (ed.), Field meeting, Anticosti–Gaspé, Québec, 1981. International Union of Geological Sciences (IUGS) and Subcommission on Silurian Stratigraphy, Ordovician-Silurian Boundary Working Group, II, Stratigraphy and Paleontology. Département de géologie, Université de Montréal, Montréal.Google Scholar
Lespérance, P. J., and Letendre, J. 1982. Some Early Silurian Phacopidae (Trilobita), p. 329336. In Mamet, B. and Copeland, M. J.(compilers, eds.), Proceedings of the Third North American Paleontological Convention 2, Toronto.Google Scholar
Lespérance, P. J., and Sheehan, P. M. 1988a [1987]. Trilobites et Brachiopodes ashgilliens (Ordovicien supérieur) de l' “Assise” de Fosse, Bande de Sambre-Meuse (Belgique). Bulletin de l'Institut Royal des Sciences Naturelles de Belgique, Sciences de la Terre, 57:91123.Google Scholar
Lespérance, P. J., and Sheehan, P. M. 1988b. Faunal assemblages of the Upper Gaspé Limestones, Early Devonian of eastern Gaspé, Quebec. Canadian Journal of Earth Sciences, 25:14321449.CrossRefGoogle Scholar
Ludvigsen, R. 1979. Fossils of Ontario, Pt. I, The trilobites. Royal Ontario Museum, Life Sciences Miscellaneous Publications, 96 p.Google Scholar
Maximova, Z. A. 1972. Novye Devonskie Trilobity Phacopoidea. Paleontologicheskiy Zhurnal, 6:8894[translation published by The American Geological Institute, 1972].Google Scholar
Miller, J. 1976. The sensory fields and life mode of Phacops rana (Green, 1832) (Trilobita). Transactions of the Royal Society of Edinburgh, 69:337367.CrossRefGoogle Scholar
Öpik, A. A. 1967. The Mindyallan fauna of north-western Queensland. Australia, Bureau of Mineral Resources, Geology and Geophysics, Bulletin 74, Vol. 1, Text, 404 p.; Vol. 2, Appendixes, Plates and Index, 167 p.Google Scholar
Richardson, J. 1857. Report for the year 1856, of Mr. James Richardson, explorer, addressed to Sir William E. Logan, provincial geologist, p. 191245. In Geological Survey of Canada Report of Progress for the years 1853–54–55–56, Toronto.Google Scholar
Ride, W. D. L., Sabrosky, C. W., Bernardi, G., Melville, R. V., Corliss, J. O., Forest, J., Key, K. H. L., and Wright, C. W. 1985. International Code of Zoological Nomenclature. 3rd edition, International Trust for Zoological Nomenclature, 338 p.Google Scholar
Romesburg, H. C. 1984. Cluster Analysis for Researchers. Lifetime Learning Publications, Belmont, California, 334 p.Google Scholar
Speyer, S. E. 1985. Moulting in phacopid trilobites. Transactions of the Royal Society of Edinburgh, 76:239253.Google Scholar
Struve, W. 1970. Beiträge zur Kenntnis der Phacopina (Trilobita), 7: Phacops-Arten aus dem Rheinischen Devon. 1. Senckenbergiana Lethaea, 51:133189.Google Scholar
Struve, W. 1982. Neue Untersuchungen über Geesops (Phacopinae: Unter- und Mittel-Devon). Senckenbergiana Lethaea, 63:473495.Google Scholar
Struve, W. 1984. Beschreibung der Trilobiten, p. 141163. In Flick, H. and Struve, W., Chotecops sollei und Chotecops ferdinandi aus devonischen Schiefern des Rheinischen Gebirges. Senckenbergiana Lethaea, 65:137–163.Google Scholar
Stumm, E. C. 1953. Trilobites of the Devonian Traverse Group of Michigan. Contributions from the Museum of Paleontology, The University of Michigan, 10:101157.Google Scholar
Stumm, E. C. 1964. Silicified trilobites from the Devonian Jeffersonville Limestone at the Falls of the Ohio. Contributions from the Museum of Paleontology, The University of Michigan, 19:114.Google Scholar
Twenhofel, W. H. 1928 [1927]. Geology of Anticosti Island. Canada, Geological Survey Memoir 154 (No. 135, Geological Series), 481 p.Google Scholar
Whitfield, R. P., and Hovey, E. O. 1900. Catalogue of the types and figured specimens in the palaeontological collection of the Geological Department, American Museum of Natural History. Part III, Beginning with the Oriskany Sandstone, Bulletin of the American Museum of Natural History, 11:189356.Google Scholar