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Terminology of glabellar lobes in trilobite larvae based on homology

Published online by Cambridge University Press:  20 May 2016

Dong-Chan Lee  and
Brian D. E. Chatterton
Dong-Chan Lee
Affiliation:
Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta T6G 2E3, Canada
Brian D. E. Chatterton
Affiliation:
Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta T6G 2E3, Canada
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Glabellar lobes of holaspid cranidia of trilobites have been numerically designated, LI, L2, etc. (Jaanusson, 1956; Henningsmoen, 1957, figure 1), or lp, 2p, etc. (Harrington, 1959), forward from the occipital ring; most trilobites have four glabellar lobes and an occipital ring. The description of morphological structures with an identical term implies that the structures are homologous in different organisms of a certain group (Inglis, 1966); this is one of the classical definitions of homology (Patterson, 1982). This also seems to be an initial conjecture of homology (“primary homology” of de Pinna, 1991). Likewise, the numerical notation of glabellar lobes should allow us to recognize homology of the lobes among trilobite taxa. Under the above traditional system, the homology is demonstrably recognized in ontogenetic stages with a distinctively differentiated protopygidium (stage 2 in Figure 1); however, this is not the case for earlier intervals occurring before transverse demarcation at the back of the head (stage 1 in Figure 1). This limitation is because the relationships of the occipital ring of the later stages to the posterior axial lobes of the earlier ones are uncertain, and this can be appreciated, when describing a phacopoid protaspis with four axial lobes (stage 1 of Rossaspis pliomeris in Figure 1). We introduce a new term, “Lp”, for the posteriormost axial lobe to remove this limitation, while keeping the traditional system useful. The previous system using letters “L” (after lobus) and “S” (after sulcus), proposed by Jaanusson (1956, p. 37), is preferred over the system using “p”, because “p” of the latter confusingly refers to lobes or furrows (e.g., Harrington and Leanza, 1957, p. 221)

Type
Research Article
Information
Journal of Paleontology , Volume 70 , Issue 3 , May 1996 , pp. 439 - 442
Copyright
Copyright © The Paleontological Society 

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References

Arthur, W. 1988. A Theory of the Evolution of Development. John Wiley and Sons, Chichester, 94 p.Google Scholar
Chapman, R. F. 1976. The Insects: Structures and Function. Elsevier, New York, 656 p.Google Scholar
Chatterton, B. D. E. 1971. Taxonomy and ontogeny of Siluro-Devonian trilobites from near Yass, New South Wales. Palaeontographica Abteilung, 137:1–108.Google Scholar
Chatterton, B. D. E. 1994. Ordovician proetide trilobite Dimeropyge, with a new species from northwestern Canada. Journal of Paleontology, 68:541–556.Google Scholar
Chatterton, B. D. E., Siveter, D. J., Edgecombe, G. D., and Hunt, A. S. 1990. Larvae and relationships of the Calymenina (Trilobita). Journal of Paleontology, 64:255–277.Google Scholar
De Pinna, M. C. C. 1991. Concepts and tests of homology in the cladistic paradigm. Cladistics, 7:367–394.Google Scholar
Edgecombe, G. D., Speyer, S. E., and Chatterton, B. D. E. 1988. Protaspid larvae and phylogenetics of encrinurid trilobites. Journal of Paleontology, 62:779–799.Google Scholar
Harrington, H. J. 1959. General description of Trilobita, p. O38–O117. In Moore, R. C. (ed.), Treatise on Invertebrate Paleontology, Part O, Arthropoda 1. Geological Society of America and University of Kansas Press, Lawrence.Google Scholar
Harrington, H. J., and Leanza, A. F. 1957. Ordovician Trilobites of Argentina. The University of Kansas Department of Geology Special Publication, Number 1, 276 p.Google Scholar
Harrington, H. J., Moore, R. C., and Stubblefield, C. J. 1959. Morphological terms applied to Trilobita, p. O117–O126. In Moore, R. C. (ed.), Treatise on Invertebrate Paleontology, Part O, Arthropoda 1. Geological Society of America and University of Kansas Press, Lawrence.Google Scholar
Henningsmoen, G. 1957. The trilobite Family Olenidae. Skrifter utgitt av Det Norske Videnskaps-Akademi I Oslo I. Matematisk-Naturvidenskapelig Klasse, Number 1, 303 p.Google Scholar
Inglis, W. G. 1966. The observational basis of homology. Systematic Zoology, 15:219–228.Google Scholar
Kluge, A. G., and Strauss, R. E. 1985. Ontogeny and systematics. Annual Review of Ecology and Systematics, 16:247–268.Google Scholar
L⊘vtrup, S. 1988. Epigenetics, p. 189–227. In Humphries, C. J. (ed.), Ontogeny and Systematics. Columbia University Press, New York.Google Scholar
Nelson, G. 1985. Outgroups and ontogeny. Cladistics, 1:29–45.Google Scholar
Patel, N. H. 1994. Developmental evolution: Insights from study of insect segmentation. Science, 266:581–590.Google Scholar
Patterson, C. 1982. Morphological characters and homology, p. 21–74. In Joysey, K. A. and Friday, A. E. (eds.), Problems of Phylogenetic Reconstruction. Systematics Association Special Volume, 21.Google Scholar
Ramsköld, L. 1991. Pattern and process in the evolution of the Odontopleuridae (Trilobita); the Selenopeltinae and Ceratocephalinae. Transactions of the Royal Society of Edinburgh: Earth Sciences, 82:143–181.Google Scholar
Riedl, R. 1978. Order in Living Organisms: a System Analysis of Evolution. John Wiley and Sons, New York, 313 p.Google Scholar
Rieppel, O. 1988. Fundamentals of Comparative Biology. Birkhäuser Verlag, Basel, 202 p.Google Scholar
Rieppel, O. 1990. Ontogeny–a way forward for systematics, a way backward for phylogeny. Biological Journal of the Linnean Society, 39:177–191.Google Scholar
Rieppel, O. 1993. The conceptual relationship of ontogeny, phylogeny, and classification (the taxic approach). Evolutionary Biology, 27:1–32.Google Scholar
Ross, R. J. Jr. 1953. Ontogenies of three Garden City (Early Ordovician) trilobites. Journal of Paleontology, 25:578–586.Google Scholar
Sander, K. 1983. The evolution of patterning mechanism, p. 137–150. In Goodwin, B. C., Holder, N., and Wylie, C. C. (eds.), Development and Evolution. University Press, Cambridge.Google Scholar
Sekiguchi, K., Yamamichi, Y., and Costlow, J. D. 1982. Horseshoe crab developmental studies I. Normal embryonic development of Limulus polyphemus compared with Tachypleus tridentatus, p. 53–73. In Bonaventura, J., Bonaventura, C., and Tesh, S. (eds.), Physiology and Biology of Horseshoe Crabs: Studies on Normal and Environmentally Stressed Animals, Progress in Clinical and Biological Research, 81.Google Scholar
St⊘rmer, L. 1942. Studies on trilobite morphology, Part II. The larval development, the segmentation and the sutures, and their bearing on trilobite classification. Norsk Geologisk Tidsskrift, 21:49–164.Google Scholar
Stubblefield, C. J. 1926. Notes on the development of Shumardia pusilla. Zoological Journal of the Linnean Society (London), 36:345–372.Google Scholar
Temple, J. T. 1952. Ontogeny of the trilobite Dalmanitina olini, Geological Magazine, 89:251–262.Google Scholar
Wagner, G. P. 1989. The biological homology concept. Annual Review of Ecology and Systematics, 20:51–69.Google Scholar
Whittington, H. B. 1959. Ontogeny of Trilobita, p. O127–O144. In Moore, R. C. (ed.), Treatise on Invertebrate Paleontology, Part O, Arthropoda 1. Geological Society of America and University of Kansas Press,) Lawrence.Google Scholar
Whittington, H. B. 1992. Trilobites (Fossils Illustrated Series, 2). Boydell Press, Woodbridge, 120 p.Google Scholar