Hostname: page-component-78c5997874-8bhkd Total loading time: 0 Render date: 2024-11-05T10:18:32.291Z Has data issue: false hasContentIssue false

Graptolite synrhabdosomes: biological or taphonomic entities?

Published online by Cambridge University Press:  08 February 2016

Juan Carlos Gutiérrez-Marco
Affiliation:
Instituto de Geología Económica (Consejo Superior de Investigaciones Científicas - Universidad Complutense de Madrid), Facultad de Ciencias Geológicas, 28040 Madrid, Spain. E-mail: [email protected]
Alfred C. Lenz
Affiliation:
Department of Earth Sciences, University of Western Ontario, London, Ontario, Canada N6A 5B7. E-mail: [email protected]

Abstract

Synrhabdosomes, structures made of mostly radially arrayed graptolite rhabdosomes attached by distal regions of their virgulae, have been considered as biological entities by some in the past, but as taphonomic structures by others more recently. Our survey of at least 200 synrhabdosomes, more than 90 of which derive from one locality in northwestern Spain, shows that all synrhabdosomes are most probably entirely monospecific assemblages composed of a more or less finite number of rhabdosomes, all of which are consistently straight or only weakly curved, and all of which bear simple, or relatively simple, thecae. We conclude, therefore, that synrhabdosomes are biological entities, and we suggest that they formed infrequently as, perhaps, temporary structures to increase food-gathering efficiency during times of lower plankton supply in local, relatively restricted water masses.

Type
Articles
Copyright
Copyright © The Paleontological Society 

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

Literature Cited

Beckly, A. J., and Maletz, J. 1991. The Ordovician graptolites Azygograptus and Jishougraptus in Scandinavia and Britain. Palaeontology 34:887925.Google Scholar
Berry, W. B. N., Wilde, P., and Quinby-Hunt, M. S. 1987. The oceanic nonsulfide oxygen minumum zone: a habitat for graptolites? Bulletin of the Geological Society of Denmark 35:103114.CrossRefGoogle Scholar
Bjerreskov, M. 1976. A new type of synrhabdosome. Bulletin of the Geological Society of Denmark 25:4147.CrossRefGoogle Scholar
Bulman, Q. M. B. 1927. A monograph of British dendroid graptolites, Part I. Palaeontographical Society Monograph (for 1925) 79(367):128.CrossRefGoogle Scholar
Bulman, Q. M. B. 1931. South American graptolites with special reference to the Nordenskiöld Collection. Arkiv för Zoologi 22A:1111.Google Scholar
Bulman, Q. M. B. 1941. Some dichograptids of the Tremadocian and Lower Ordovician. Annals and Magazine of Natural History, ser. 11, 7:100121.CrossRefGoogle Scholar
Bulman, Q. M. B. 1948. Some Shropshire Ordovician graptolites. Geological Magazine 85:222228.CrossRefGoogle Scholar
Bulman, Q. M. B. 1950. Graptolites from the Dictyonema Shales of Quebec. Quarterly Journal of the Geological Society of London 106:6399.CrossRefGoogle Scholar
Bulman, Q. M. B. 1964. Lower Palaeozoic plankton. Quarterly Journal of the Geological Society of London 120:455476.CrossRefGoogle Scholar
Bulman, Q. M. B. 1970. Part V. Graptolithina with sections on Enteropneusta and Pterobranchia. Teichert, C., ed. (2d ed.) of Moore, R. C., ed. Treatise on Invertebrate Paleontology. Geological Society of America and University of Kansas Press, Lawrence, Kans.Google Scholar
Chen, X. 1984. Silurian graptolites from southern Shaanxi and northern Sichuan with special reference to classification of Monograptidae. Palaeontologica Sinica, Whole Number 166, New Series B 20:1102[In Chinese with English summary.]Google Scholar
Clark, T. H. 1972. Stratigraphy and structure of the St. Lawrence Lowland of Quebec. Twenty-fourth International Geological Congress, Montreal. Guidebook to Excursion 52.Google Scholar
Decker, C. E. 1952. Stratigraphic significance of graptolites of Athens Shale. Bulletin of the American Association of Petroleum Geologists 36:1145Google Scholar
Ekström, G. 1937. Upper Didymograptus Shale in Scania. Sveriges Geologiska Undersökning Series C 403:153.Google Scholar
Erdtmann, B.-D. 1982. A reorganization and proposed phylogenetic classification of planktic Tremadoc (Early Ordovician) dendroid graptolites. Norsk Geologisk Tidsskrift 63:121144.Google Scholar
Finney, S. C. 1986. Graptolite biofacies and correlation of eustatic, subsidence, and tectonic events in the Middle to Upper Ordovician of North America. Palaios 1:435461.CrossRefGoogle Scholar
Fortey, R. A., and Bell, A. 1987. Branching geometry and function of multiramous graptoloids. Paleobiology, 13:119.CrossRefGoogle Scholar
Ge, M.-y., and Chen, S.-e. 1995. Synrhabdosome of Orthograptus cf. attenuatus Rickards from Nanzheng, China. Acta Palaeontologica Sinica 34:205211[In Chinese and English.]Google Scholar
Goldman, D. 1995. Taxonomy, evolution, and biostratigraphy of the Orthograptus quadrimucronatus species group (Ordovician, Graptolithina). Journal of Paleontology 69:516540.CrossRefGoogle Scholar
Goldman, D., and Mitchell, C. E. 1994. Three-dimensional graptolites from the upper Middle Ordovician Neuville Formation, Quebec. New York State Museum Bulletin 481:8799.Google Scholar
Hahn, F. F. 1912. On the Dictyonema-fauna of Navy Island, New Brunswick. Annals of the New York Academy of Science 22:135160.CrossRefGoogle Scholar
Hall, J. 1865. Graptolites of the Quebec group. Figures and descriptions of Canadian organic remains, decade II. Geological Survey of Canada, Montreal.CrossRefGoogle Scholar
Haury, L. R., McGowan, J. A., and Wiebe, P. H. 1978. Patterns and processes in the time-space scales of plankton distribution. Pp. 277327in Steele, J. H., ed. Spatial patterns in plankton communities. NATO Conference Series, Series IV. Marine Sciences. Plenum, New York.Google Scholar
Hernández Sampelayo, P. 1950. Agrupación de graptolítidos infrasilurianos biseriados. Notas y Comunicaciones del Instituto Geológico y Minero de España 20:8387.Google Scholar
Hundt, R. 1965. Aus der Welt der Graptolithen. Commerzia Verlag und Druckerei Seidel & Co., Berlin and Bonn.Google Scholar
Jackson, D.E., Kerr, J. W., and Morrow, D. W. 1976. A synrhabdosome of Monograptus fanicus Koren' from the Lower Devonian of Devon Island, District of Franklin. Geological Survey of Canada, Contributions to Canadian Paleontology, Bulletin 256:3940.Google Scholar
Kirk, N. H. 1978. Mode of life of graptolites. Acta Palaeontologica Polonica 23:533555.Google Scholar
Koren’, T. N. 1991. The C. lundgreni extinction event in Central Asia and its bearing on graptolite biochronology within the Homerian. Proceedings of the Estonian Academy of Sciences 40:7478.Google Scholar
Kozlowski, R. 1949. Les graptolithes et quelques nouveaux groupes d'animaux du Tremadoc de la Pologne. Palaeontologica Polonica 3:1235.Google Scholar
Kozlowski, R. 1971. Early development stages and mode of life of graptolites. Acta Palaeontologica Polonica 16:313343.Google Scholar
Lenz, A. C. 1990. Ludlow and Pridoli (Upper Silurian) graptolite biostratigraphy of the central Arctic Islands: a preliminary report. Canadian Journal of Earth Sciences 27:10741083CrossRefGoogle Scholar
Lenz, A. C. 1993. Late Wenlock and Ludlow (Silurian) Plectograptinae (retiolitid graptolites), Cape Phillips Formation, Arctic Canada. Bulletins of American Paleontology 104:152.Google Scholar
Lenz, A. C. 1994. The graptolites “Pristiograptus” praedeubeli (Jaeger) and “Pristiograptus” ludensis (Murchison) from Arctic Canada: their taxonomy and evolution. Canadian Journal of Earth Sciences 31:14191426.CrossRefGoogle Scholar
Lenz, A. C. 1995. Upper Homerian (Wenlock, Silurian) graptolites and graptolite biostratigaphy, Arctic Archipelago, Canada. Canadian Journal of Earth Sciences 32:13781392.CrossRefGoogle Scholar
Lenz, A. C., and Melchin, M. J. 1986. A synrhabdosome of Saetograptus fritschi cf. linearis (Boucek) from Cornwallis Island, Arctic Canada. Canadian Journal of Earth Sciences 23:18541857.CrossRefGoogle Scholar
Lin, Y.-k. 1988. On proximal tufts of threads in Dictyonema. Acta Palaeontologica Sinica 27:218237[In Chinese and English.]Google Scholar
Melchin, M. J., and DeMont, M. E. 1995. Possible propulsion modes in Graptoloidea: a new model for graptoloid locomotion. Paleobiology 21:110120.CrossRefGoogle Scholar
Palmer, D., and Rickards, R. B. 1991. Graptolites: writing on the rocks. Fossils Illustrated, Vol. 1. Boydell, Woodbridge, England.Google Scholar
Rickards, R. B. 1975. Palaeoecology of the Graptolithina, an extinct Class of the Phylum Hemichordata. Biological Reviews 50:397436.CrossRefGoogle Scholar
Rickards, R. B. 1996. The graptolite nema: problem to all our solutions. Geological Magazine 133:343346.CrossRefGoogle Scholar
Rigby, S. 1993. Population analysis and orientation studies of graptoloids from the Middle Ordovician Utica Shale, Quebec. Palaeontology 36:267282.Google Scholar
Rigby, S., and Rickards, R. B. 1989. New evidence for the life habit of graptoloids from physical modelling. Paleobiology 15:402413.CrossRefGoogle Scholar
Riva, J. 1974. A revision of some Ordovician graptolites of eastern North America. Palaeontology 17:140.Google Scholar
Ruedemann, R. 1895. Development and mode of growth of Diplograptus, McCoy. New York State Geological Survey, Annual Report for 1894:219249.Google Scholar
Ruedemann, R. 1904. Graptolites of New York, Part I. Graptolites of the lower beds. New York State Museum Memoir 7:455807.Google Scholar
Ruedemann, R. 1908. Graptolites of New York, Part II. Graptolites of higher beds. New York State Museum Memoir 11:457583.Google Scholar
Ruedemann, R. 1925. The Utica and Lorraine Formations of New York, Part II. Systematic paleontology, No. 1. Plants, sponges, corals, graptolites, crinoids, worms, bryozoans, brachiopods. New York State Museum Bulletin 262.Google Scholar
Ruedemann, R. 1947. Graptolites of North America. Geological Society of America Memoir 19.CrossRefGoogle Scholar
Schauer, M. 1971. Biostratigraphie und Taxionomie der Graptolithen des tieferen Silurs unter besonderer Berücksichtigung der tektonischen Deformation. Freiberger Forschungshefte. C273, Paläontologie:1185.Google Scholar
Siveter, D. J., Owens, R. M., and Thomas, A. T. 1989. Silurian field excursions. A geotraverse across Wales and the Welsh Borderland. National Museum of Wales, Geological Series 10:1133.Google Scholar
Tomczyk, H. 1962. Stratigraphy of old Palaeozoic sediments from boreholes at Uszkowce near Lubaczów. Acta Geologica Polonica, Ksiega Pamiatkowa ku czci prof. Jana Samsonowicka:123148. [In Polish.]Google Scholar
Underwood, C. J. 1993. The position of graptolites within Lower Palaeozoic planktic ecosystems. Lethaia 26:189202.CrossRefGoogle Scholar
Walters, M. 1977. Middle and Upper Ordovician graptolites from the St. Lawrence Lowlands, Quebec, Canada. Canadian Journal of Earth Sciences 14:939952.CrossRefGoogle Scholar
Williams, S. H. 1987. Upper Ordovician graptolites from the D. complanatus Zone of the Moffat and Girvan districts and their significance for correlation. Scottish Journal of Geology 23:6592.CrossRefGoogle Scholar
Williams, S. H. 1991. Stratigraphy and graptolites of the Upper Ordovician Point Leamington Formation, central Newfoundland. Canadian Journal of Earth Sciences 28:581600.CrossRefGoogle Scholar
Zalasiewicz, J. 1984. Dichograptid synrhabdosomes from the Arenig of Britain. Palaeontology 27:425429.Google Scholar