Hostname: page-component-586b7cd67f-g8jcs Total loading time: 0 Render date: 2024-11-22T05:02:24.863Z Has data issue: false hasContentIssue false

A revision of Palaeacmaea (Upper Cambrian) (?Cnidaria)

Published online by Cambridge University Press:  14 July 2015

Gerald F. Webers
Affiliation:
Geology Department, Macalester College, St. Paul, Minnesota 55105
Ellis L. Yochelson
Affiliation:
National Museum of Natural History, Washington, D.C 20560

Abstract

Palaeacmaea typica, the type species of the genus, and P. irvingi, the only other Late Cambrian taxon considered congeneric are redescribed herein. Their morphology suggests that they are neither Monoplacophora, where they are currently assigned, nor are they Mollusca. Specimens of P. irvingi demonstrate considerable variation in shape, interpreted as distortion of a flexible integument, of essentially no thickness. A neotype is designated for P. irvingi; it is interpreted as a medusiform fossil, possibly a cnidarian. Only the holotype of P. typica is known, but it shows comparable features. The genus and the family Palaeacmaeide are placed in Phylum Incertae Sedis. Four Ordovician species previously assigned to Palaeacmaea, show none of the characteristics noted, and they are tentatively reassigned to other genera.

Type
Research Article
Copyright
Copyright © The Paleontological Society 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Bassler, R. S. 1915. Bibliographic index of American Ordovician and Silurian fossils. Bulletin United States National Museum, 92, 1,521 p. (two volumes).CrossRefGoogle Scholar
Billings, E. 1872. On some fossils from the primordial rocks of Newfoundland. Canadian Naturalist and Quarterly Journal of Science, new series 6:465479.Google Scholar
Brown, D. A., Clayton, L., Madison, F. W., and Evans, T. J. 1983. Three billion years of geology: A field trip through the Archean, Proterozoic, Paleozoic and Pleistocene. Geology of the Black River Falls Area of Wisconsin, Guidebook for the 47th Tri-State Geological Field Conference. Wisconsin Geological and Natural History Survey Field Trip Guidebook 9, 51 p.Google Scholar
Chamberlin, T. C. 1883. Part 1: General Geology, 3-300, Geology of Wisconsin, Survey of 1873-1879, 1, 724 p.Google Scholar
Dawson, J. W. 1868. Acadian geology: an account of the geological structure and mineral resources of Nova Scotia and portions of the neighboring provinces of British America. Second edition, 694 p.Google Scholar
Fisher, D. W. 1968. Geology of the Plattsburgh and Rouses Point New York-Vermont Quadrangles. New York State Museum and Science Service Map and chart series, 10, 51 p.Google Scholar
Grabau, A. W., and Shimer, H. W. 1909. North American Index Fossils; Invertebrates. 1, 853 p. A. G. Seiler and Company, New York.CrossRefGoogle Scholar
Hall, J., and Whitfield, R. P. 1872. Descriptions of new species of fossils from the Devonian rocks of Iowa: with a preliminary note on the formations [Knight 1941, p. 394 notes “This paper was “Published in July 1872, in advance of the (23rd) Report of the State Cabinet” where the paper again appears but with different pagination].Google Scholar
Hall, J., and Whitfield, R. P. 1873. Notice of two new species of fossil shells from the Potsdam sandstone of New York. 23rd Annual Report of the New York State Cabinet, 241242.Google Scholar
Kase, T. 1988. Reinterpretation of Brunonia annulata (Yokoyama) as an Early Cretaceous carinariid mesogastropod (Mollusca). Journal of Paleontology, 62:766771.Google Scholar
Knight, J. B. 1941. Paleozoic Gastropod Genotypes. Geological Society of America Special Paper, 32, 510 p.Google Scholar
Knight, J. B. 1952. Primitive fossil gastropods and their bearing on gastropod classification. Smithsonian Miscellaneous Collections, 117(13):156.Google Scholar
Knight, J. B., and Yochelson, E. L. 1960. Monoplacophora, p. 177184. In Moore, R. C. (ed.), Treatise on Invertebrate Paleontology, Pt I, Mollusca 1. Geological Society of America and University of Kansas Press, Lawrence.Google Scholar
Landing, E., and Narbonne, G. M. 1992. Scenella and a chondrophorine (medusoid hydrozoan) from the basal Cambrian (Placentian) of Newfoundland. Journal of Paleontology, 66:388.CrossRefGoogle Scholar
Narbonne, G. M., Myrow, P., Landing, E., and Anderson, M. M. 1991. A chondrophorine (medusoid hydrozoan) from the basal Cambrian (Placentian) of Newfoundland. Journal of Paleontology, 65:185191.CrossRefGoogle Scholar
Oliver, W. A. Jr. 1984. Conchopeltis: Its affinities and significance. Palaeontographica Americana, 54:41147.Google Scholar
Raymond, P. E. 1905. The fauna of the Chazy Limestone, American Journal of Science, 20:353382.Google Scholar
Peel, J. S. 1991. Functional morphology, evolution, and systematics of Early Paleozoic univalved molluscs. Gronlands Geologiske Undersogelse, Bulletin 161, 116 p.Google Scholar
Shimer, H. W., and Shrock, R. R. 1944. Index fossils of North America. John Wiley, New York, 837 p.Google Scholar
Stanley, G. M., and Kanjie, Y. 1985. The first Mesozoic chondrophorine (medusoid hydrozoan) from the Lower Cretaceous of Japan. Palaeontology, 28:101109.Google Scholar
Stenzel, S. R. 1983. Stratigraphy and sedimentology of the Upper Cambrian Wonewoc Formation in the Baraboo and Kickapoo River Valleys, Wisconsin, Unpublished , University of Wisconsin, Madison, 199 p.Google Scholar
Ulrich, E. O., and Scofield, W. H. 1897. The Lower Silurian Gastropoda of Minnesota, Minnesota Geological Survey, 3:8131081.Google Scholar
Vostokova, V. A. 1962. [Cambrian gastropods from the Siberian platform and Taimir]. Sbornik stati po paleontologsi i biostratigraphi, vispusrc, 28:5174. [in Russian].Google Scholar
Waggoner, B. M., and Collins, A.G. 1995. A new chondrophorine (Cnidaria, Hydrozoa) from the Cadiz Formation (Middle Cambrian) of California. Palaontologische Zeitschrift, 69:711.CrossRefGoogle Scholar
Walcott, C. D. 1912. New York Potsdam-Hoyt fauna. Smithsonian Miscellaneous Collections, 57(12):251304.Google Scholar
Walcott, C. D. 1884. On the Cambrian fauna of North America; Preliminary studies. U.S. Geological Survey Bulletin 10, 74 p.Google Scholar
Whiteaves, J. H. 1884, On some new, imperfectly characterized or previously unrecorded species of fossils from the Guelph formation of Ontario. Geological and Natural History Survey of Canada, Palaeozoic Fossils, 3:143.Google Scholar
Whitfield, R. P. 1878. Preliminary descriptions of new species of fossils from the lower geological formations of Wisconsin. Wisconsin Geological Survey Annual Report for 1877, p. 50890.Google Scholar
Whitfield, R. P. 1882. Paleontology, p. 163363. In Chamberlin, T. C. (ed.), Geology of Wisconsin, Survey of 1873-1879, Volume 4.Google Scholar
Whitfield, R. P. 1899. List of fossils, types, and figured specimens used in the paleontological work of R. P. Whitfield, showing where they are probably to be found at the present time. Annals of the New York Academy of Science, 12:139186.CrossRefGoogle Scholar
Yochelson, E. L. 1984. North American Middle Ordovician Scenella and Macroscenella as possible chondrophorid coelenterates. Palaeontographica Americana, 54:148153.Google Scholar
Yochelson, E. L. 1988. A new genus of Patellacea (Gastropoda) from the Middle Ordovician of Utah; The oldest known example of the superfamily. New Mexico Bureau of Mines & Mineral Resources, Memoir 44:195200.Google Scholar
Yochelson, E. L. 1991. Problematica/Incertae Sedis, p. 287296. In Simonetta, A. M. and Conway Morris, S. (eds.), The early evolution of Metazoa and the significance of problematic taxa. University Press, Cambridge.Google Scholar
Yochelson, E. L. 1994. Macroscenella (Mollusca) from the Middle Ordovician of Wisconsin; a reinterpretation and reassignment. Journal of Paleontology, 68:12521256.CrossRefGoogle Scholar
Yochelson, E. L., and Fedonkin, M. A. 1993. Paleobiology of Climactichnites, an enigmatic Late Cambrian fossil. Smithsonian Contributions to Paleobiology, 74, 74 p.Google Scholar
Yochelson, E. L., and Gil Cid, D. 1984. Reevaluation of the systematic position of Scenella. Lethaia, 17:331340.CrossRefGoogle Scholar
Yochelson, E. L., and Stanley, G. D. Jr. 1982. An Early Ordovician patelliform gastropod Palaeolophacmaea reinterpreted as a coelenterate. Lethaia, 15:323330.Google Scholar
Zittel, K. A. (ed.). 1913. Textbook of Paleontology. C. R. Eastman. 1,839 p. Macmillan and Company, London. [Adapted from the German of Karl A. von Zittel]Google Scholar