Hostname: page-component-cd9895bd7-fscjk Total loading time: 0 Render date: 2024-12-21T13:48:51.120Z Has data issue: false hasContentIssue false
  • English
  • Français

Compaction-related deformation in Cambrian olenelloid trilobites and its implications for fossil morphometry

Published online by Cambridge University Press:  20 May 2016

Mark Webster  and
Nigel C. Hughes
Mark Webster
Affiliation:
Department of Earth Sciences, University of California, Riverside, California 92521
Nigel C. Hughes
Affiliation:
Department of Earth Sciences, University of California, Riverside, California 92521
Get access Rights & Permissions [Opens in a new window]

Abstract

Morphometric analyses of silicified and nonsilicified (preserved in shale) specimens of the olenelloid trilobites Olenellus (Olenellus) gilberti Meek (in White, 1874) and Nephrolenellus geniculatus Palmer, 1998, from the Lower Cambrian C-Shale Member of the Pioche Formation show that even well-preserved specimens in shales have undergone significant changes in lateral as well as vertical dimensions as a result of compaction. Analyses of cephalic landmarks show that in both species compaction causes posteriordirected collapse of the anterior lobe of the glabella, adaxial deformation of the ocular lobes, and abaxial and anterior splaying of genal regions. These shape changes are explicable in terms of observed exoskeletal fracture patterns. Landmarks show an increase in scatter around their ontogenetic trajectories that is generally proportional to the degree of lateral shift each landmark has undergone. Interspecific differences in compactional response may depend on the relative convexity of the cephalon. Olenellus (Olenellus) gilberti is a low-convexity species and shows marked lateral shape change, particularly in the genal region. Nephrolenellus geniculatus is more convex and shows less severe lateral shape change. Landmarks of both species exhibit an average trebling of the degree of scatter around their average ontogenetic trajectories in compacted samples. Because even well-preserved specimens in shales differ in shape from their precompactional appearance, results of morphometric studies utilizing metric distances between landmarks in trilobites where compaction can be detected must be interpreted with caution.

Type
Research Article
Information
Journal of Paleontology , Volume 73 , Issue 2: Papers from the Second International Trilobite Conference, August 1997 , March 1999 , pp. 355 - 371
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

Anderson, L. I. 1994. Xiphosurans from the Westphalian D of the Radstock Basin, Somerset Coalfield, the South Wales Coalfield and Mazon Creek, Illinois. Proceedings of the Geologists’ Association, 105:265–275.Google Scholar
Anderson, L. I. 1997. The xiphosuran Liomesaspis from the Montceau-les-Mines Konservat-Lagerstätte, Massif Central, France. Neues Jahrbuch für Geologie und Paläontologie. Abhandlungen, 204:415–436.Google Scholar
Anderson, L. I., and Horrocks, C. 1995. Valloisella lievinensis Racheboeuf, 1992 (Chelicerata; Xiphosura) from the Westphalian B of England. Neues Jahrbuch für Geologie und Paläontologie. Monatshefte, 11:647–658.CrossRefGoogle Scholar
Bookstein, F. L. 1986. Size and shape spaces for landmark data in two dimensions. Statistical Science, 1:181–242.Google Scholar
Bookstein, F. L. 1990. High-order features of shape change for landmark data, p. 237–250. In Rohlf, F. J. and Bookstein, F. L. (eds.), Proceedings of the Michigan Morphometrics Workshop. Special Publication No. 2, University of Michigan Museum of Zoology, Ann Arbor, Michigan.Google Scholar
Bookstein, F. L. 1991. Morphometric Tools for Landmark Data. Cambridge University Press, New York, 435 p.Google Scholar
Boulter, M. C. 1968. A species of compressed lycopod sporophyll from the Upper Coal Measures of Somerset. Palaeontology, 11:445–457.Google Scholar
Brett, C. E., and Baird, G. C. 1993. Taphonomic approaches to temporal resolution in stratigraphy: Examples from Paleozoic marine mudrocks, p. 250–274. In Kidwell, S. M. and Behrensmeyer, A.K. (eds.), Taphonomic Approaches to Time Resolution in Fossil Assemblages. Short Courses in Paleontology 6, Paleontological Society, Knoxville, Tennessee.Google Scholar
Briggs, D. E. G., and Williams, S. H. 1981. The restoration of flattened fossils. Lethaia, 14:157–164.Google Scholar
Campbell, L., and Kauffman, M. E. 1969. Olenellus fauna of the Kinzers Formation, southeastern Pennsylvania. Proceedings of the Pennsylvania Academy of Science, 43:172–176.Google Scholar
Chapman, R. E. 1990. Conventional Procrustes Approaches, p. 251–267. In Rohlf, F. J. and Bookstein, F. L. (eds.), Proceedings of the Michigan Morphometrics Workshop. Special Publication Number 2, University of Michigan Museum of Zoology, Ann Arbor, Michigan.Google Scholar
Clayton, G. 1972. Compression structures in the Lower Carboniferous miospore Dictyotriletes admirabilis Playford. Palaeontology, 15:121–124.Google Scholar
Cooper, R. A. 1990. Interpretation of tectonically deformed fossils. New Zealand Journal of Geology and Geophysics, 33:321–332.Google Scholar
David, B., and Laurin, B. 1992. Procrustes: an interactive program for shape analysis using landmarks. Version 2.0. Paléontologie Analytique publishers, Dijon.Google Scholar
David, B., and Laurin, B. 1996. Morphometrics and cladistics: measuring phylogeny in the sea urchin Echinocardium. Evolution, 50:348–359.Google Scholar
Doveton, J. H. 1979. Numerical methods for the reconstruction of fossil material in three dimensions. Geological Magazine, 116:215–226.Google Scholar
Evans, W. D., and Amos, D. H. 1961. An example of the origin of coal-balls. Proceedings of the Geologists’ Association, 72:445–454.CrossRefGoogle Scholar
Ferguson, L. 1962. Distortion of Crurithyris urei (Fleming) from the Viséan rocks of Fife, Scotland, by compaction of the comtaining sediment. Journal of Paleontology, 36:115–119.Google Scholar
Ferguson, L. 1963. Estimation of the compaction factor of a shale from distorted brachiopod shells. Journal of Sedimentary Petrology, 33:796–798.Google Scholar
Foote, M. 1991a. Morphologic pattens of diversification: examples from trilobites. Palaeontology, 34:461–485.Google Scholar
Foote, M. 1991b. Analysis of morphological data, p. 59–86. In Gilinsky, N. L. and Signor, P. W. (eds.), Analytical Paleobiology. Short Courses in Paleontology. Paleontological Society.Google Scholar
Foote, M. 1995. Morphological diversification of Paleozoic crinoids. Paleobiology, 21:273–299.CrossRefGoogle Scholar
Fortey, R. A. 1974. The Ordovician trilobites of Spitsbergen. I. Olenidae. Norsk Polarinstitutt Skrifter 160, 129 p.Google Scholar
Geyer, G. 1996. The Moroccan fallotaspidid trilobites revisited. Beringeria, 18:89–199.Google Scholar
Gower, J. C. 1970. Statistical methods of comparing different multivariate analyses of the same data, p. 138–149. In Hudson, F. R., Kendall, D. G., and Tautu, P. (eds.), Mathematics in the Arachaeological and Historical Sciences. Edinburgh University Press, Edinburgh.Google Scholar
Gower, J. C. 1975. Generalized Procrustes analysis. Psychometrika, 40:33–51.Google Scholar
Hahn, G., Brauckmann, C., and Skala, W. 1972. Kulm-Trilobiten aus der striatus-Zone (Dinantium, Cu IIIß) des Rheinischen Schiefer-Gebirges und des Harzes. Senckenbergiana Lethaea, 53:31–63.Google Scholar
Harris, T. M. 1974. Williamsoniella lignieri: its pollen and the compression of spherical pollen grains. Palaeontology, 17:125–148.Google Scholar
Hughes, N. C. 1993. Distribution, taphonomy and functional morphology of the Upper Cambrian trilobite Dikelocephalus. Milwaukee Public Museum Contributions in Biology and Geology 84:1–49.Google Scholar
Hughes, N. C. 1994. Ontogeny, intraspecific variation, and systematics of the Late Cambrian trilobite Dikelocephalus. Smithsonian Contributions to Paleobiology 79:1–89.Google Scholar
Hughes, N. C. In press. Statistical and imaging methods applied to deformed fossils. In Harper, D. A. T. (ed.), Statistics in Palaeontology. John Wiley Press, London.Google Scholar
Hughes, N. C., and Chapman, R. E. 1995. Growth and variation in the Silurian proetide trilobite Aulacopleura konincki and its implications for trilobite palaeobiology. Lethaia, 28:333–353.Google Scholar
Hughes, N. C., and Rushton, A. W. A. 1990. Computer-aided restoration of a Late Cambrian ceratopygid trilobite from Wales, and its phylogenetic implications. Palaeontology, 33:429–445.Google Scholar
Kaesler, R. L., Kontrovitz, M., and Taunton, S. 1993. Crushing strength of Puriana pacifica (Ostracoda), an experimental approach to taphonomy. Journal of Paleontology, 67:1005–1010.Google Scholar
Lele, S.M 1993. Euclidean Distance Matrix Analysis (EDMA): Estimation of mean form and mean form difference. Mathematical Geology, 25:573–602.Google Scholar
Lieberman, B. S. 1998. Cladistic analysis of the Early Cambrian olenelloid trilobites. Journal of Paleontology, 72:59–78.Google Scholar
Lloyd, G. E., and Ferguson, C. C. 1989. Belemnites, strain analysis and regional tectonics: a critical appraisal. Tectonophysics, 168:239–253.Google Scholar
MacLeod, N. 1991. Punctuated anagenesis and the importance of stratigraphy to paleobiology. Paleobiology, 17:167–188.Google Scholar
Merriam, C. W. 1964. Cambrian rocks of the Pioche mining district, Nevada. Geological Survey Professional Paper 469, 59 p.Google Scholar
Palmer, A. R. 1998. Terminal Early Cambrian extinction of the Olenellina: Documentation from the Pioche Formation, Nevada. Journal of Paleontology, 72:650–672.Google Scholar
Pickett, J. W. 1984. A new freshwater limuloid from the mid Triassic of New South Wales. Palaeontology, 27:609–621.Google Scholar
Ramsköld, L., Jun-Yuan, C., Edgecombe, G., and Gui-Qing, Z. 1996. Preservational folds simulating tergite junctions in tegopeltid and naraoiid arthropods. Lethaia, 29:15–20.Google Scholar
Rex, G. M., and Chaloner, W. G. 1983. The experimental formation of plant compression fossils. Palaeontology, 26:231–252.Google Scholar
Rickards, R. B., and Riva, J. 1981. Glyptograptus? persculptatus (Salter), its tectonic deformation, and its stratigraphic significance for the Carys Mills Formation of N.E. Maine, U.S.A.. Geological Journal, 16:219–235.Google Scholar
Rohlf, F. J. 1990. Rotational fit (Procrustes) Methods, p. 227–236. In Rohlf, F. J. and Bookstein, F. L. (eds.), Proceedings of the Michigan Morphometrics Workshop. Special Publication Number 2, University of Michigan Museum of Zoology, Ann Arbor, Michigan.Google Scholar
Rohlf, F. J., and Slice, D. 1990. Extensions of the Procrustes method for the optimal superimposition of landmarks. Systematic Zoology, 39:40–59.Google Scholar
Sadler, P. M. 1974. Trilobites from the Gorran Quartzites, Ordovician of south Cornwall. Palaeontology, 17:71–93.Google Scholar
Schönemann, P. H. 1970. On metric multidimensional scaling. Psychometrika, 35:349–366.Google Scholar
Shaw, A. B. 1957. Quantitative trilobite studies II. Measurement of the dorsal shell of non-agnostidean trilobites. Journal of Paleontology, 31:193–207.Google Scholar
Siegel, A. F., and Benson, R. H. 1982. A robust comparison of biological shapes. Biometrics, 38:341–350.Google Scholar
Smith, G. R. 1990. Homology in morphometrics and phylogenetics, p. 325–338. In Rohlf, F. J. and Bookstein, F. L. (eds.), Proceedings of the Michigan Morphometrics Workshop. Special Publication Number 2, University of Michigan Museum of Zoology, Ann Arbor, Michigan.Google Scholar
Smith, G. R. 1998. Species level phenotypic variation in lower Paleozoic trilobites. Paleobiology, 24:17–36.Google Scholar
Sneath, P. H. A. 1967. Trend-surface analysis of transformation grids. Journal of Zoology, 151:65–122.Google Scholar
Speyer, S. E. 1991. Trilobite taphonomy: a basis for comparative studies of arthropod preservation, functional anatomy and behaviour, p. 194–219. In Donovan, S. K. (ed.), The Process of Fossilization. Columbia University Press, New York.Google Scholar
Sundberg, F. A. 1974. Distortion factor of Latham Shale trilobites. Bulletin of the Southern California Paleontological Society, 6:121–124.Google Scholar
Sundberg, F. A., and McCollum, L. B. 1997. Oryctocehpalids (Corynexochida: Trilobita) of the Lower-Middle Cambrian boundary interval from California and Nevada. Journal of Paleontology, 71:1065–1090.Google Scholar
Vogel, B. R., and Durden, C. J. 1966. The occurrence of stigmata in a Carboniferous scorpion. Journal of Paleontology, 40:655–658.Google Scholar
Wagner, P. J. 1995. Testing evolutionary constraint hypotheses: examples with early Paleozoic gastropods. Paleobiology, 21:248–272.Google Scholar
White, C. A. 1874. Preliminary report upon invertebrate fossils. U. S. Geographic and Geologic Surveys West of the 100th Meridian Report, p. 5–27.Google Scholar
Wilmot, N. V. 1990. Biomechanics of trilobite exoskeletons. Palaeontology, 33:749–768.Google Scholar