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A new genus and two new species of multiplacophorans (Mollusca, Polyplacophora, Neoloricata), Mississippian (Chesterian), Indiana

  • Stephaney S. Puchalski (a1), Claudia C. Johnson (a1), Erle G. Kauffman (a1) and Douglas J. Eernisse (a2)


Deltaplax new genus, Deltaplax burdicki new species, and Deltaplax dellangeloi new species (Mollusca, Polyplacophora, Neoloricata, Multiplacophora) from the Mississippian Lower Buffalo Wallow Group (Chesterian) of Indiana, USA are described. the new genus is established by one partially articulated and one associated specimen with marginal fringes of two types of large spines, bilaterally symmetrical head and tail valves, and fifteen medial valves arranged in three longitudinal columns similar to those described previously for other multiplacophorans. the two specimens represent separate species differentiated by morphologies of the auxiliary valves, one type of spine, and subtrapezoidal versus triangular tail valves. the tail valve of the articulated specimen also had sutural laminae that projected under the preceding intermediate valve. the presence of sutural laminae allows for placement of multiplacophorans in Subclass Neoloricata of Class Polyplacophora. the head, intermediate, and tail valves are mucronate with comarginal growth lines and ridged insertion plates that probably inserted into soft tissue comparable to the girdle of modern polyplacophorans. the new specimens also indicate one left-handed, one auxiliary, and one right-handed valve in multiplacophorans was equivalent to a single bilaterally-symmetrical intermediate valve of extant polyplacophorans. However, multiplacophoran head valves have plates that project from the lower layer at the lateral margins and articulate with the first intermediate valves that overlap the head and second intermediate valves. These features have not been observed in more typical neoloricates, fossil or modern. Pending systematic revision of the class, Multiplacophora thus is retained as a separate order distinguished by the unique shared characters.



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Ashby, E. and Cotton, B. C. 1939. New fossil chitons from the Miocene and Pliocene of Victoria. Records of the South Australian Museum, 6:209242.
Bergenhayn, J. R. M. 1955. Die fossilen schwedischen Loricaten nebst einer vorläufigen Revision des Systems der ganzen Klasse Loricata. Kungligia Fysiografiska Sällskapets Handlingar, 66(NS 8):141.
Blainville, H. M. D. de. 1816. Prodrome d'une nouvelle distribution systématique du règne animal, Bulletin des Sciences, Société Philomathique de Paris, 105124.
Cherns, L. 2004. Early Palaeozoic diversification of chitons (Polyplacophora, Mollusca) based on new data from the Silurian of Gotland, Sweden. Lethaia, 37:445456.
Cuvier, G. 1797. Tableau élémentaire d l'histoire naturelle des animaux. Baudoin, Paris, 710 p.
Dzik, J. 1986. Turrilepadida and other Machaeridia, p. 116134. In Hoffman, and Nitecki, (eds.), Problematic Fossil Taxa, Oxford University Press, New York.
Eernisse, D. J. 1986. The genus Lepidochitona Gray, 1821 (Mollusca: Polyplacophora) in the northeastern Pacific Ocean (Oregonian and California provinces). Zoologische Verhandelingen, supplement 228:152.
Hall, J. and Clarke, J. M. 1888. Trilobites and other Crustacea of the Oriskany, Upper Helderberg, Hamilton, Portage, Chemung and Catskill Groups. New York Geological Survey, Paleontology, 7:1236.
Hoare, R. D. 2002. European Paleozoic Polyplacophora, Multiplacophora, and Turrilepadida in United States repositories. Journal of Paleontology, 76:95108.
Hoare, R. D. and Mapes, R. H. 1995. Relationships of the Devonian Strobilepis and related Pennsylvanian problematica. Acta Palaeontologica Polonica, 40:111128.
Hoare, R. D. and Mapes, R. H. 1996. Late Paleozoic problematic sclerites of hercolepadid affinities. Journal of Paleontology, 70:341347.
Hoare, R. D. and Mapes, R. H. 2000. New data on the genus Diadeloplax Hoare and Mapes, 1995. Journal of Paleontology, 74:976978.
Kirkby, J. W. 1859. On the Permian Chitonidae. Quarterly Journal of the Geological Society of London, 15:607626.
Kues, B. S. 1978. Polyplacophora from the Salem Limestone (Mississippian) in central Indiana. Journal of Paleontology, 52:300310.
Oehlert, M. D. 1850. Documents pour servir a l'étude des faunes Dévoniennes dans l'ouest de la France. Mémoirs de Société Géologie de France, series 3, 1:1517.
Puchalski, S. S. 2002. Taphonomy of chitons (Mollusca, Polyplacophora). Friday Harbor Class Papers Zoology 533, Summer 2002:169193.
Puchalski, S. S., Johnson, C. C., and Eernisse, D. J. 2008. The effect of sampling bias on the fossil record of chitons (Mollusca, Polyplacophora). American Malacological Bulletin, in press.
Sigwart, J. D. and Sutton, M. D. 2007. Deep Molluscan Phylogeny: Synthesis of Palaeontological and Neontological Data. Proceedings of the Royal Society B, 274:24132419.
Sirenko, B. 2006. New outlook on the system of chitons (Mollusca: Polyplacophora). Japanese Journal of Malacology, 65:2749.
Smith, A. G. and Hoare, R. D. 1987. Paleozoic Polyplacophora: A checklist and bibliography. Occasional papers of the California Academy of Sciences, 146:171.
Speyer, S. E. and Brett, C. E. 1988. Taphofacies models for epeiric sea environments: Middle Paleozoic examples. Palaeogeography, Palaeoclimatology, Palaeoecology, 63:225262.
Van Belle, R. A. 1981. Catalogue of fossil chitons: (Mollusca: Polyplacophora). W. Backhuys, Rotterdam, 84 p.
Vendrasco, M. J. 1999. Early evolution of the Polyplacophora (chitons). Unpublished Ph.D. dissertation, University of California, Los Angeles, 232 p.
Vendrasco, M. J., Wood, T. E., and Runnegar, B. N. 2004. Articulated Palaeozoic fossil with 17 plates greatly expands disparity of early chitons. Nature, 429:288291.
Withers, T. H. 1915. Some Palaeozoic fossils referred to the Cirripedia. Geological Magazine, 6:112123.

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A new genus and two new species of multiplacophorans (Mollusca, Polyplacophora, Neoloricata), Mississippian (Chesterian), Indiana

  • Stephaney S. Puchalski (a1), Claudia C. Johnson (a1), Erle G. Kauffman (a1) and Douglas J. Eernisse (a2)


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