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Morphometric analysis of ontogeny and allometry of the Middle Ordovician trilobite Triarthrus becki

Published online by Cambridge University Press:  08 April 2016

Keonho Kim ,
H. David Sheets ,
Robert A. Haney  and
Charles E. Mitchell
Keonho Kim
Affiliation:
Department of Geology, 876 Natural Sciences Complex, State University of New York at Buffalo, Buffalo, New York 14260. E-mail: [email protected]
H. David Sheets
Affiliation:
Department of Physics, Canisius College, 2001 Main Street, Buffalo, New York 14208. E-mail: [email protected]
Robert A. Haney
Affiliation:
Department of Geology, 876 Natural Sciences Complex, State University of New York at Buffalo, Buffalo, New York 14260. E-mail: [email protected]
Charles E. Mitchell
Affiliation:
Department of Geology, 876 Natural Sciences Complex, State University of New York at Buffalo, Buffalo, New York 14260. E-mail: [email protected]
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Abstract

Traditionally, the distinction between meraspis and holaspis among trilobites has been based on the achievement of the full adult complement of thoracic segments. Using a large sample (over 700 specimens collected from a single bed) we explore the utility of employing the ontogenetic trajectory of the cranidium as an alternative means to differentiate trilobite growth stages. This method is particularly useful for species represented solely by exuviae and disarticulated individuals. We use geometric morphometrics to examine shape change among cranidia ranging in size from 0.9 mm to 11.6 mm in cephalic length. The 114 measured specimens exhibit a rather continuous gradation in size in which no distinct instars are evident.

The meraspid and holaspid specimens exhibit allometry when partial warp scores and uniform components of shape derived from thin-plate spline analysis are regressed onto log centroid size. To describe allometric shape change, deformation vectors from the smallest to the largest specimen in both ontogenetic stages are presented in three different superimposition settings by using a new software program. We have concluded that a new superimposition method (the Sliding Baseline Registration) is a useful tool for visualizing allometry in organisms that contain an axis of symmetry. As a result, we conclude that allometry is evident in meraspides and holaspides, but the degree of allometry in holaspides is very small relative to that in meraspides. The boundary between meraspis and holaspis in Triarthrus becki appears to correspond to a large change in the rate of ontogenetic change, but neither to a change in the direction of that trajectory nor to a cessation of ontogenetic change. This boundary also corresponds to a cranidium centroid size that matches well previous determinations that holaspis begins at about 2.8 mm in cephalic length.

Type
Articles
Information
Paleobiology , Volume 28 , Issue 3 , Summer 2002 , pp. 364 - 377
Copyright
Copyright © The Paleontological Society 

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References

Literature Cited

Baird, G. C., Brett, C. E., and Lehmann, D. 1992. The Trenton-Utica problem revisited: new observations and ideas regarding Middle-Late Ordovician stratigraphy and depositional environments in central New York. Pp. 1–40in Goldstein, A., ed. Guidebook to field excursions, 64th annual meeting of the New York State Geological Association held at Colgate University. New York State Geological Association.Google Scholar
Beecher, C. E. 1893. A larval form of Triarthrus. American Journal of Science 46:361–362.Google Scholar
Beecher, C. E. 1894. On the mode of occurrence, the structure and development of Triarthrus becki. American Geologist 13:38–43.Google Scholar
Beecher, C. E. 1895. The larval stages of trilobites. American Geologist 16:166–197.Google Scholar
Bookstein, F. L. 1991. Morphometric tools for landmark data: geometry and biology. Cambridge University Press, Cambridge.Google Scholar
Bookstein, F. L. 1996. Combining the tools of geometric morphometrics. Pp. 131–151in Marcus, L. F., Corti, M., Loy, A., Naylor, G., and Slice, D. E., eds. Advances in morphometrics. Plenum, New York.Google Scholar
Brett, C. E., and Baird, G. C. 1993. Taphonomic approaches to temporal resolution in stratigraphy: Examples from Paleozoic marine mudrocks. In Kidwell, S. M. and Behrensmeyer, A. K., eds. Taphonomic approaches to time resolution in fossil assemblages. Short Courses in Paleontology 6:250–274. Paleontological Society, Knoxville, Tenn.Google Scholar
Brett, C. E., and Seilacher, A. 1991. Fossil Lagerstätten: a taphonomic consequence of event sedimentation. Pp. 283–297in Einsele, G., Ricken, W., and Seilacher, A., eds. Cycles and events in stratigraphy. Springer, Berlin.Google Scholar
Cisne, J. L. 1973. Life history of an Ordovician trilobite Triarthrus eatoni. Ecology 54:135–142.Google Scholar
Cisne, J. L. 1981. Triarthrus eatoni (Trilobita): anatomy of its exoskeletal, skeletomuscular, and digestive systems. Palaeontographica Americana 9:99–141.Google Scholar
Cisne, J. L., and Rabe, B. D. 1978. Coenocorrelation: gradient analysis of fossil communities and its applications in stratigraphy. Lethaia 11:341–364.Google Scholar
Cisne, J. L., Molenock, J., and Rabe, B. D. 1980. Evolution in a cline: the trilobite Triarthrus along an Ordovician depth gradient. Lethaia 13:47–59.Google Scholar
Cisne, J. L., Karig, D. E., Rabe, B. D., and Hay, B. J. 1982. Topography and tectonics of the Taconic outer trench slope as revealed through gradient analysis of fossil assemblages. Lethaia 15:229–246.CrossRefGoogle Scholar
Dryden, I. L., and Mardia, K. V. 1998. Statistical shape analysis. Wiley, Chichester, England.Google Scholar
Fisher, D. W. 1979. Folding in the foreland, Middle Ordovician Dolgeville facies, Mohawk Valley, New York. Geology 7:455–459.Google Scholar
Goldman, D., Mitchell, C. E., Bergström, S. M., Delano, J. W., and Tice, S. J. 1994. K-bentonites and graptolite biostratigraphy in the Middle Ordovician of New York State and Quebec: a new chronostratigraphic model. Palaios 9:124–143.Google Scholar
Goldman, D., Mitchell, C. E., and Joy, M. P. 1999. The stratigraphic distribution of graptolites in the classic upper Middle Ordovician Utica Shale of New York State: an evolutionary succession or a response to relative sea-level change? Paleobiology 25:273–294.Google Scholar
Goldman, D., Mitchell, C. E., and Joy, M. P. 1989. Deposition in the oxygen-deficient Taconic foreland basin, Late Ordovician. In B. D. Keith, ed. The Trenton Group (Upper Ordovician series) of eastern North America. American Association of Petroleum Geologists Studies in Geology 29:113–134.Google Scholar
Hughes, N. C. 1999. Statistical and imaging methods applied to deformed fossils. Pp. 127–155in Harper, D. A. T., ed. Numerical paleobiology. Wiley, 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 paleobiology. Lethaia 28:333–353.Google Scholar
Jones, D. S., and Gould, S. J. 1999. Direct measurement of age in fossil Gryphaea: the solution to a classic problem in heterochrony. Paleobiology 25:158–187.Google Scholar
Kay, G. M. 1937. Stratigraphy of the Trenton Group. Geological Society of America Bulletin 48:233–302.CrossRefGoogle Scholar
Kay, G. M. 1943. Mohawkian Series on West Canada Creek, New York. American Journal of Science 241:597–606.Google Scholar
Kay, G. M. 1953. Geology of the Utica Quadrangle, New York. New York State Museum Bulletin 347.Google Scholar
Kendall, D. G. 1977. The diffusion of shape. Advances in Applied Probability 9:428–430.Google Scholar
Ludvigsen, R., and Tuffnell, P. A. 1983. A revision of the Ordovician olenid trilobite Triarthrus Green. Geological Magazine 120:567–577.Google Scholar
Ludvigsen, R., and Tuffnell, P. A. 1994. The last olenacean trilobite: Triarthrus in the Whitby Formation (Upper Ordovician) of southern Ontario. In E. Landing, ed. Studies in stratigraphy and paleontology in honor of Donald W. Fisher. New York State Museum Bulletin 481:183–212.Google Scholar
Månsson, K. 1998. Middle Ordovician olenid trilobites (Triarthrus Green and Porterfieldia Cooper) from Jämtland, central Sweden. Transactions of the Royal Society of Edinburgh (Earth Sciences) 89:47–62.Google Scholar
McKinney, M. L. 1999. Heterochrony: beyond words. Paleobiology 25:149–153.Google Scholar
Mehrtens, C. J. 1989. Bioclastic turbidites in the Trenton Limestone: significance and criteria for recognition. In B. D. Keith, ed. The Trenton Group (Upper Ordovician series) of eastern North America. American Association of Petroleum Geologists Studies in Geology 29:87–112.Google Scholar
Mitchell, C. E., Goldman, D., Baird, G. C., Brett, C. E., Bergström, S. M., and Delano, J. L. 1993. Age and facies relationships of the Middle Ordovician Dolgeville Formation in the Mohawk Valley, New York State: a possible carbonate fan deposit. Geological Society of America Abstracts with Programs 25(6):A75.Google Scholar
Mitchell, C. E., Goldman, D., Delano, J. W., Samson, S. D., and Bergstrom, S. M. 1994. Temporal and spatial distribution of bio-zones and facies relative to geochemically correlated K-bentonites in the Middle Ordovician Taconic foredeep. Geology 22:715–718.Google Scholar
Raw, F. 1925. The development of Leptoplastus salteri (Calloway) and of other trilobites (Olenidae, Ptychoparidae, Conocoryphidae, Paradoxidae, Phacopidae, and Mesonacidae). Quarterly Journal of the Geological Society of London 81:223–324.Google Scholar
Rohlf, F. J. 1998. TpsRelw, Version 1.18. Department of Ecology and Evolution, State University of New York, Stony Brook, N.Y.Google Scholar
Rohlf, F. J., and Bookstein, F. L. 1990. Proceedings of the Michigan morphometrics workshop. University of Michigan Museum of Zoology Special Publication No. 2. Ann Arbor, Mich.Google Scholar
Rohlf, F. J., and Marcus, L. F. 1993. A revolution in morphometrics. Trends in Ecology and Evolution 8:129–132.Google Scholar
Rohlf, F. J., and Slice, D. E. 1990. Extension of the Procrustes method for the optimal superimposition of landmarks. Systematic Zoology 39:40–59.Google Scholar
Sheets, H. D. 2001a. Regress6. Department of Physics, Canisius College, Buffalo, N.Y. (http://www.canisius.edu/~sheets/morphsoft.html).Google Scholar
Sheets, H. D. 2001b. VecComparel2. Department of Physics, Canisius College, Buffalo, N.Y. (http://www.canisius.edu/~sheets/morphsoft.html).Google Scholar
Slice, D. E. 1993. GRF-ND Generalized rotational fitting of n-dimensional landmark data. Department of Ecology and Evolution. State University of New York, Stony Brook, N.Y.Google Scholar
Speyer, S. E., and Brett, C. E. 1985. Clustered trilobite assemblages in the Middle Devonian Hamilton Group. Lethaia 18:85–103.CrossRefGoogle Scholar
Stubblefield, C. J. 1926. Notes on the development of a trilobite, Shumardia pusilla (Sars). Zoological Journal of the Linnean Society of London 35:345–372.Google Scholar
Walcott, C. D. 1879. The Utica slate and related formations. Fossils of the Utica slate and metamorphoses of Triarthrus becki. Transactions of the Albany Institute No. 10.Google Scholar
Webster, M., and Hughes, N. C. 1999. Compaction-related deformation in Cambrian Olenelloid trilobites and its implications for fossil morphometry. Journal of Paleontology 73:355–371.CrossRefGoogle Scholar
Webster, M., Sheets, H. D., and Hughes, N. C. 2001. Testing of allometric heterochrony in trilobites. Pp. 105–144in Zelditch, M. L., ed. Beyond heterochrony. Wiley-Liss, New York.Google Scholar
Whittington, H. B. 1957. Ontogeny of Elliptocephala, Paradoxides, Sao, Blainia and Triarthrus (Trilobita). Journal of Paleontology 31:934–946.Google Scholar
Zelditch, M. E., and Fink, W. L. 1995. Allometry and developmental integration of body growth in a Piranha, Pygocentrus nattereri (Teleostei: Ostariophysi). Journal of Morphology 223:341–355.Google Scholar
Zelditch, M. E., Bookstein, F. L., and Lundrigan, B. L. 1992. Ontogeny of integrated skull growth in the cotton rat Sigmodon fulviventer. Evolution 46:1164–1180.Google Scholar
Zelditch, M. E., Bookstein, F. L., and Lundrigan, B. L. 1993. The ontogenetic complexity of developmental constraints. Journal of Evolutionary Biology 6:621–641.Google Scholar
Zelditch, M. L., Sheets, H. D., and Fink, W. L. 2000. Spatiotemporal reorganization of growth rates in the evolution of ontogeny. Evolution 54:1363–1371.Google Scholar