Skip to main content Accessibility help

Body-size scaling of metabolic rate in the trilobite Eldredgeops rana

  • Douglas S. Glazier (a1), Matthew G. Powell (a2) and Travis J. Deptola (a3)


We infer the body-size scaling slope of metabolic rate in a trilobite by applying a cell-size model that has been proposed to explain metabolic scaling in living organisms. This application is especially tractable in fossil arthropods with well-preserved compound eyes because the number and size of eye facets appear to be useful proxies for the relative number and size of cells in the body. As a case study, we examined the ontogenetic scaling of facet size and number in a ∼390-Myr-old local assemblage of the trilobite Eldredgeops rana, which has well-preserved compound eyes and a wide body-size range. Growth in total eye lens area resulted from increases in both facet area and number in relatively small (presumably young) specimens, but only from increases in facet area in large (presumably more mature) specimens. These results suggest that early growth in E. rana involved both cell multiplication and enlargement, whereas later growth involved only cell enlargement. If the cell-size model is correct, then metabolic rate scaled allometrically in E. rana, and the scaling slope of log metabolic rate versus log body mass decreased from ∼0.85 to 0.63 as these animals grew. This inferred age-specific change in metabolic scaling is consistent with similar changes frequently observed in living animals. Additional preliminary analyses of literature data on other trilobites also suggest that the metabolic scaling slope was <1 in benthic species, but ∼1 in pelagic species, as has also been observed in living invertebrates. The eye-facet size (EFS) method featured here opens up new possibilities for examining the bioenergetic allometry of extinct arthropods.



Hide All
Agutter, P. S., and Tuszynski, J. A. 2011. Analytic theories of allometric scaling. Journal of Experimental Biology 214:10551062.
Arendt, J. D. 2000. Allocation of cells to proliferation vs. differentiation and its consequences for growth and development. Journal of Experimental Zoology B 288:219–23.
Banavar, J. R., Maritan, A., and Rinaldo, A. 1999. Size and form in efficient transportation networks. Nature 399:130132.
Banavar, J. R., Moses, M. E., Brown, J. H., Damuth, J., Rinaldo, A., Sibly, R. M., and Maritan, A. 2010. A general basis for quarter-power scaling in animals. Proceedings of the National Academy of Sciences USA 107:1581615820.
Brett, C. E., and Baird, G. C. 1994. Depositional sequences, cycles, and foreland basin dynamics in the late Middle Devonian (Givetian) of the Genesee Valley and western Finger Lakes region. InBrett, C. E. and Scatterday, J., eds. Field trip guidebook. New York State Geological Association Guidebook 66:505585.
Brett, C. E., Bartholomew, A. J., and Baird, G. C. 2007. Biofacies recurrence in the Middle Devonian of New York State: an example with implications for evolutionary paleoecology. Palaios 22:306324.
Brown, J. H., Gillooly, J. F., Allen, A. P., Savage, V. M., and West, G. B. 2004. Toward a metabolic theory of ecology. Ecology 85:17711789.
Chown, S. L., Marais, E., Terblanche, J. S., Klok, C. J., Lighton, J. R. B., and Blackburn, T. M. 2007. Scaling of insect metabolic rate is inconsistent with the nutrient supply network model. Functional Ecology 21:282290.
Clarke, J. M. 1889. The structure and development of the visual area in the trilobite, Phacops rana, Green. Journal of Morphology 2:253270.
Clarkson, E. N. K. 1966. Schizochroal eyes and vision of some Silurian acastid trilobites. Palaeontology 9:129.
Clarkson, E. N. K. 1973. Morphology and evolution of the eye in Upper Cambrian Olenidae (Trilobita). Palaeontology 16:735763.
Clarkson, E. N. K. 1979. The visual system of trilobites. Palaeontology 22:122.
Clarkson, E. N. K., and Ahlberg, P. 2002. Ontogeny and structure of a new, miniaturized and spiny olenid trilobite from southern Sweden. Palaeontology 45:122.
Clarkson, E., Levi-Setti, R., and Horváth, G. 2006. The eyes of trilobites: the oldest preserved visual system. Arthropod Structure and Development 35:247259.
Czarnołeski, M., Kozłowski, J., Dumiot, G., Bonnet, J.-C., Mallard, J., and Dupont-Nivet, M. 2008. Scaling of metabolism in Helix aspersa snails: changes during ontogeny and response to selection for increased size. Journal of Experimental Biology 211:391400.
Davison, J. 1955. Body weight, cell surface and metabolic rate in anuran Amphibia. Biological Bulletin 109:407419.
Davison, J. 1956. An analysis of cell growth and metabolism in the crayfish (Procambarus alleni). Biological Bulletin 110:264273.
Dexter, T. A., Sumrall, C. D., and McKinney, M. L. 2009. Allometric strategies for increasing respiratory surface area in the Mississippian blastoid Pentremites. Lethaia 42:127137.
Finnegan, S., McClain, C. M., Kosnik, M. A., and Payne, J. L. 2011. Escargots through time: an energetic comparison of marine gastropod assemblages before and after the Mesozoic Marine Revolution. Paleobiology 37:252269.
Fortey, R. A. 2004. The lifestyles of trilobites. American Scientist 92:446453.
Glazier, D. S. 2005. Beyond the ‘3/4-power law': variation in the intra- and interspecific scaling of metabolic rate in animals. Biological Reviews 80:611662.
Glazier, D. S. 2006. The 3/4-power law is not universal: evolution of isometric, ontogenetic metabolic scaling in pelagic animals. BioScience 56:325332.
Glazier, D. S. 2008. Effects of metabolic level on the body-size scaling of metabolic rate in birds and mammals. Proceedings of the Royal Society of London B 275:14051410.
Glazier, D. S. 2010. A unifying explanation for diverse metabolic scaling in animals and plants. Biological Reviews 84:111138.
Glazier, D. S., Butler, E. M., Lombardi, S. A., Deptola, T. J., Reese, A. J., and Satterthwaite, E. V. 2011. Ecological effects on metabolic scaling: amphipod responses to fish predators in freshwater springs. Ecological Monographs 81:599618.
Gregory, T. R. 2002. A bird's eye view of the C-value enigma: genome size, cell size, and metabolic rate in the class Aves. Evolution 56:121130.
Hemmingsen, A. M. 1960. Energy metabolism as related to body size and respiratory surfaces, and its evolution. Reports of the Steno Memorial Hospital and Nordisk Insulin Laboratorium 9:1110.
Kerkhoff, A. J., and Enquist, B. J. 2009. Multiplicative by nature: why logarithmic transformation is necessary in allometry. Journal of Theoretical Biology 257:519521.
Kirby, M. X. 2001. Differences in growth rate and environment between Tertiary and Quaternary Crassostrea oysters. Paleobiology 27:84103.
Kirby, M. X., and Jackson, J. B. C. 2004. Extinction of a fast-growing oyster and changing ocean circulation in Pliocene tropical America. Geology 32:10251028.
Kleiber, M. 1932. Body size and metabolism. Hilgardia 6:315353.
Knoll, A.H., Bambach, R. K., Canfield, D. E., and Grotzinger, J. P. 1996. Comparative Earth history and Late Permian mass extinction. Science 273:452457.
Knoll, A.H., Bambach, R. K., Payne, J. L., Pruss, S., and Fischer, W. W. 2007. Paleophysiology and end-Permian mass extinction. Earth and Planetary Science Letters 256:295313.
Kozłowski, J., Konarzewski, M., and Gawelczyk, A. T. 2003. Cell size as a link between noncoding DNA and metabolic rate scaling. Proceedings of the National Academy of Sciences USA 100:1408014085.
Kozłowski, J., Czarnoleski, M., François-Krassowska, A., Maciak, S., and Pis, T. 2010. Cell size is positively correlated between different tissues in passerine birds and amphibians, but not necessarily in mammals. Biology Letters 6:792796.
Land, M. F. 1997. Visual acuity in insects. Annual Review of Entomology 42:147177.
Lee, M. S. Y., Jago, J. B., García-Bellido, D. C., Edgecombe, G. D., Gehling, J. G., and Paterson, J. R. 2011. Modern optics in exceptionally preserved eyes of Early Cambrian arthropods from Australia. Nature 474:631634.
Maciak, S., Janko, K., Kotusz, J., Choleva, L., Boroń, A., Juchno, D., Kujawa, R., Kozłowski, J., and Konarzewski, M. 2011. Standard metabolic rate (SMR) is inversely related to erythrocyte and genome size in allopolyploid fish of the Cobitis taenia hybrid complex. Functional Ecology 25:10721078.
Makarieva, A. M., Gorshkov, V. G., Li, B.-L., Chown, S. L., Reich, P. B., and Gavrilov, V. M. 2008. Mean mass-specific metabolic rates are strikingly similar across life's major domains: evidence for life's metabolic optimum. Proceedings of the National Academy of Sciences USA 105:1699416999.
Martin, A.P., and Palumbi, S. R. 1993. Body size, metabolic rate, generation time, and the molecular clock. Proceedings of the National Academy of Sciences USA 90:40874091.
McCormick, T., and Fortey, R. A. 1998. Independent testing of a paleobiological hypothesis: the optical design of two Ordovician pelagic trilobites reveals their paleobathymetry. Paleobiology 24:235253.
McKinney, M. L., and Sumrall, C. D. 2011. Ambulacral growth allometry in edrioasteroids: functional surface-volume change in ontogeny and phylogeny. Lethaia 44:102108.
McNamara, K. J. 1978. Paedomorphosis in Scottish Olenellid trilobites (Early Cambrian). Palaeontology 21:635655.
Miller, K. B. 1991. High-resolution correlation within a storm-dominated muddy epeiric sea: taphofacies of the Middle Devonian Wanakah Member, western New York. InLanding, E. and Brett, C. E., eds. Dynamic stratigraphy and depositional environments of the Hamilton Group (Middle Devonian) in New York State, Part II. New York State Museum Bulletin 469:129153.
Miller, K. B., Brett, C. E., and Parsons, K. M. 1988. The paleoecologic significance of storm-generated disturbance within a Middle Devonian muddy epeiric sea. Palaios 3:3552.
Oakley, T. H. 2003. On homology of arthropod compound eyes. Integrative and Comparative Biology 43:522530.
Pérez-Claros, J. A. 2005. Allometric and fractal exponents indicate a connection between metabolism and complex septa in ammonites. Paleobiology 31:221232.
Peters, R. H. 1983. The ecological implications of body size. Cambridge University Press, New York.
Pis, T. 2008. Resting metabolic rate and erythrocyte morphology in early development of thermoregulation in the precocial grey partridge (Perdix perdix). Comparative Biochemistry and Physiology A 151:211218.
Reich, P. B., Tjoelker, M. G., Machado, J.-L., and Oleksyn, J. 2006. Universal scaling of respiratory metabolism, size and nitrogen in plants. Nature 439:457461.
Rigby, S. and Milsom, C. V. 2000. Origins, evolution, and diversification of zooplankton. Annual Review of Ecology and Systematics 31:293313.
Riisgård, H. U. 1998. No foundation of a ‘3/4 power scaling law' for respiration in biology. Ecology Letters 1:7173.
Riveros, A. J., and Enquist, B. J. 2011. Metabolic scaling in insects supports the WBE model. Journal of Insect Physiology 57:688693.
Savage, V. M., Gillooly, J. F., Woodruff, W. H., West, G. B., Allen, A. P., Enquist, B. J., and Brown, J. H. 2004. The predominance of quarter-power scaling in biology. Functional Ecology 18:257282.
Schmidt-Nielsen, K. 1984. Scaling: why is animal size so important? Cambridge University Press, New York.
Schoenemann, B., Clarkson, E. N. K., Ahlberg, P., and Álvarez, M. E. D. 2010. A tiny eye indicating a planktonic trilobite. Palaeontology 53:695701.
Seymour, R. S., Smith, S. L., White, C. R., Henderson, D. M., and Schwarz-Wings, D. 2012. Blood flow to long bones indicates activity metabolism in mammals, reptiles, and dinosaurs. Proceedings of the Royal Society of London B 279:451456.
Starostová, Z., Kubička, L., Konarzewski, M., Kozłowski, J., and Kratochvíl, L. 2009. Cell size but not genome size affects scaling of metabolic rate in eyelid geckos. American Naturalist 174:E100E105. doi:10.1086/603610.
Stevenson, R. D., Hill, M. G., and Bryant, P. J. 1995. Organ and cell allometry in Hawaiian Drosophila: how to make a big fly. Proceedings of the Royal Society of London B 259:105110.
Struve, W. 1990. Paläozoologie III: 1986–1990. Courier Forschungsinstitut Senckenberg 127:251279.
Szarski, H. 1983. Cell size and the concept of wasteful and frugal evolutionary strategies. Journal of Theoretical Biology 105:201209.
Thomas, A. T. 2005. Developmental palaeobiology of trilobite eyes and its evolutionary significance. Earth-Science Reviews 71:7793.
Vermeij, G. J. 1995. Economics, volcanoes, and Phanerozoic revolutions. Paleobiology 21:125152
Vijendravarma, R. K., Narasimha, S., and Kawecki, T. J. 2011. Plastic and evolutionary responses of cell size and number to larval malnutrition in Drosophila melanogaster. Journal of Evolutionary Biology 24:897903.
Wehner, R. 1981. Spatial vision in arthropods. Pp. 287616inAutrum, H., ed. Comparative physiology and evolution of vision in invertebrates. Handbook of Sensory Physiology, Vol. VII/6C. Springer, Berlin.
West, G. B., Brown, J. H., and Enquist, B. J. 1997. A general model for the origin of allometric scaling laws in biology. Science 276:122126.
White, C. R., Cassey, P., and Blackburn, T. M. 2007. Allometric exponents do not support a universal metabolic allometry. Ecology 88:315323.
Whiteley, T. E., Kloc, G. J., and Brett, C. E. 2002. Trilobites of New York. Cornell University Press, Ithaca, N.Y.
Whittington, H. B. 1957. The ontogeny of trilobites. Biological Reviews 32:421469.
Wurster, C. M., and Patterson, W. P. 2003. Metabolic rate of late Holocene freshwater fish: evidence from δ13C values of otoliths. Paleobiology 29:492505.
Zhang, X., and Clarkson, E. N. K. 1990. The eyes of Lower Cambrian Eodiscid trilobites. Palaeontology 33:911932.

Body-size scaling of metabolic rate in the trilobite Eldredgeops rana

  • Douglas S. Glazier (a1), Matthew G. Powell (a2) and Travis J. Deptola (a3)


Altmetric attention score

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed