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Evidence for segment polarity during regeneration in the Devonian asteropygine trilobite Greenops widderensis

Published online by Cambridge University Press:  14 July 2015

Kenneth J. McNamara  and
Megan E. Tuura
Kenneth J. McNamara
Affiliation:
1Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ, U.K.,
Megan E. Tuura
Affiliation:
2Department of Geology, University of Otago, Dunedin 9054, New Zealand
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Abstract

A complete molted exoskeleton of the asteropygine phacopid trilobite Greenops widderensis Lieberman and Kloc, 1997 from the Middle Devonian (Givetian) Widder Formation in southwestern Ontario, Canada that has suffered predatory trauma provides insights into the sequence of regeneration of segments. The molt configuration is such that it is possible to interpret the molting technique used by the trilobite. Predatory trauma affected four areas of the exoskeleton. The pygidium shows loss of the spinose margin on one side and damage to a single spine on the other; one genal spine has been broken and partially regrown; and the posterior of the glabella has been removed. It is thought that the first three traumas occurred during life, as these areas affected show signs of exoskeletal regeneration. The fourth trauma probably occurred to the exuvium. Analysis of the degree of regeneration of the pygidial pleurae indicates that there was an anteroposterior polarity to the regeneration. Other examples in the literature suggest that this regeneration polarity pattern may have been widespread in trilobites. It is suggested that, as in modern arthropods and annelids, this sequential regeneration was under the control of segmentation polarity genes.

Type
Research Article
Information
Journal of Paleontology , Volume 85 , Issue 1 , January 2011 , pp. 106 - 110
Copyright
Copyright © The Paleontological Society 

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References

Babcock, L. E. 1993. Trilobite malformations and the fossil record of behavioral asymmetry. Journal of Paleontology, 67:217–229.Google Scholar
Bartholomew, A. J., Brett, C. E., Desantis, M., Baird, G. C., and Tsujita, C. 2006. Sequence stratigraphy of the Middle Devonian at the border of the Michigan Basin: Correlations with New York and implications for sea-level change and paleogeography. Northeastern Geology and Environmental Sciences, 28:2–33.Google Scholar
Bely, A. E. and Wray, G. A. 2001. Evolution of regeneration and fission in annelids: insights from engrailed- and orthodenticle-class gene expression. Development, 128:2781–2791.Google Scholar
Conway Morris, S. and Jenkyns, R. J. F. 1985. Healed injuries in early Cambrian trilobites from South Australia. Alcheringa, 9:167–177.Google Scholar
Day, S. J. and Lawrence, P. A. 2000. Measuring dimensions: the regulation of size and shape. Development, 127:2977–2987.Google Scholar
Fusco, G. 2005. Trunk segment numbers and sequential segmentation in myriapods. Evolution and Development, 7:608–617.Google Scholar
Green, J. 1837. Description of several new trilobites. American Journal of Science, 32(1):343–349.Google Scholar
Gurdon, J. B. and Bourillot, P.-Y. 2001. Morphogen gradient interpretation. Nature, 413:797–803.Google Scholar
Hessin, W. A. 1987. Partial regeneration of a genal spine by the trilobite Ceraurus plattinensis . Lethaia, 21:285–288.Google Scholar
Hughes, N. C. 2003a. Trilobite tagmosis and body patterning from morphological and developmental perspective. Integrative and Comparative Biology, 43:185–206.Google Scholar
Hughes, N. C. 2003b. Trilobite body patterning and the evolution of arthropod tagmosis. BioEssays, 25:386–395.Google Scholar
Hughes, N. C. 2007. The evolution of trilobite body patterning. Annual Review of Earth and Planetary Sciences, 35:401–434.Google Scholar
Lieberman, B. S. and Kloc, G. J. 1997. Evolutionary and biogeographic patterns in the Asteropyginae (Trilobita, Devonian) Delo, 1935. Bulletin of the American Museum of Natural History, 232:1–127.Google Scholar
McNamara, K.J., Yu, F., and Zhou, Z. 2003. Ontogeny and heterochrony in the oryctocephalid trilobite Arthricocephalus from the Early Cambrian of China. Special Papers in Palaeontology, 70:103–126.Google Scholar
Meinhardt, H. 1983. Cell determination boundaries as organizing regions for secondary embryonic fields. Developmental Biology, 96:375–385.Google Scholar
Minelli, A., Fusco, G. and Hughes, N. C. 2003. Tagmata and segment specification in trilobites. Special Papers in Palaeontology, 70:31–43.Google Scholar
Owen, A. W. 1985. Trilobite abnormalities. Transactions of the Royal Society of Edinburgh, 76:255–272.Google Scholar
Pratt, B. 2001. Probable predation on Upper Cambrian trilobites and its relevance for the extinction of soft-bodied Burgess Shale-type animals. Lethaia, 31:73–88.Google Scholar
Rogulja, D. and Irvine, K. D. 2005. Regulation of cell proliferation by a morphogen gradient. Cell, 123:449–461.Google Scholar
Signor, P. W. and Brett, C. E. 1984. The mid-Paleozoic precursor to the Mesozoic marine revolution. Paleobiology, 10:229–245.Google Scholar
Šnajdr, M. 1981. Bohemian Proetidae with malformed exoskeletons (Trilobita). Sborník Geologickńch Věd Paleontologie, 24:37–60.Google Scholar
Speyer, S. E. 1985. Moulting in phacopid trilobites. Transactions of the Royal Society of Edinburgh, 76:239–253.CrossRefGoogle Scholar
Speyer, S. E. and Brett, C. E. 1985. Clustered trilobite assemblages in the Middle Devonian Hamilton Group. Lethaia, 18:85–103.Google Scholar
Speyer, S. E. and Brett, C. E. 1986. Trilobite taphonomy and Middle Devonian taphofacies. Palaios, 1:312–327.Google Scholar
Stauffer, C. R. 1915. The Devonian of Southwestern Ontario. Geological Survey of Canada Memoir 34, 341 p.Google Scholar
Sundberg, F.A. 2000. Homeotic evolution in Cambrian trilobites. Paleobiology, 26:258–270.Google Scholar
Tsujita, C. J., Brett, C. E., Topor, M. and Topor, J. 2008. Evidence of high-frequency storm disturbance in the Middle Devonian Arkona Shale, southwestern Ontario. Journal of Taphonomy, 49–68.Google Scholar
van Hengstum, P. J. and Gröcke, D. R. 2008. Stable isotope record of the Eifelian-Givetian boundary Kačák-otomari Event (Middle Devonian) from Hungry Hollow, Ontario, Canada. Canadian Journal of Earth Sciences, 45:353–366.Google Scholar
Wright, J. D. and Wright, E. P. 1961. A study of Middle Devonian Widder Formation of southwestern Ontario. Contributions from the Museum of Paleontology, University of Michigan, 16:287–300.Google Scholar