Hostname: page-component-586b7cd67f-gb8f7 Total loading time: 0 Render date: 2024-11-30T19:37:50.738Z Has data issue: false hasContentIssue false
  • English
  • Français

Probable microvertebrates, vertebrate-like fossils, and weird things from the Wisconsin Ordovician

Published online by Cambridge University Press:  20 May 2016

David L. Clark ,
John K. Sorenson ,
Andrea N. Ladd  and
James R. Freiheit
David L. Clark
Affiliation:
Department of Geology and Geophysics, University of Wisconsin, Madison 53706,
John K. Sorenson
Affiliation:
Department of Geology and Geophysics, University of Wisconsin, Madison 53706,
Andrea N. Ladd
Affiliation:
Department of Geology and Geophysics, University of Wisconsin, Madison 53706,
James R. Freiheit
Affiliation:
Department of Geology and Geophysics, University of Wisconsin, Madison 53706,
Get access Rights & Permissions [Opens in a new window]

Abstract

Phosphatic microfossils including probable microvertebrates occur in the Early and Middle Ordovician rocks of Wisconsin. The eight types described here include the probable ostracoderm Anatolepis, and six unidentified but possible vertebrate fragments as well as the palaeoscolecid worm Milaculum. These fossils are rare, but at two localities several specimens per kg were recovered over significant stratigraphic intervals. The high concentration of certain fossils in the lower part of the Galena Group suggests that there is stratigraphic value in their description. Identification of similar material or of articulated assemblages of these fossils may eventually lead to identification of biologic affinities.

Type
Research Article
Information
Journal of Paleontology , Volume 73 , Issue 6 , November 1999 , pp. 1201 - 1209
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

Bockelie, T., and Fortey, R. A. 1976. An Early Ordovician vertebrate. Nature, 260:36–38.Google Scholar
Clark, D. L., and Miller, J. F. 1969. Early evolution of conodonts. Geological Society of America Bulletin, 80:125–134.CrossRefGoogle Scholar
Dzik, J. 1986. Chordate affinities of the conodonts, p. 240–254. In Hoffman, A. and Nitecki, M. H. (eds.), Problematic Fossil Taxa. Oxford Monograph on Geology and Geophysics, 5. Oxford Press, New York.Google Scholar
Ethington, R. L., and Clark, D. L. 1981. Lower and Middle Ordovician conodonts from the Ibex area, western Millard County, Utah. Brigham Young University Geology Studies, 28:(2), 160 p.Google Scholar
Fraunfelter, G. H. 1970. Cephalaspids from the Middle Ordovician Platteville Limestone. Trans. Illinois State Academy of Science, 63:14–17.Google Scholar
Janvier, P. 1996. Early Vertebrates. Oxford Monographs on Geology and Geophysics, number 33, Clarendon Press, Oxford, 393 p.Google Scholar
Jerre, F. 1993. Conulariid microfossils from the Silurian Lower Visy Beds of Gotland, Sweden. Palaeontology, 36:403–424.Google Scholar
Müller, K. J., and Hinz-Schallreuter, I. 1993. Palaeoscolecid worms from the Middle Cambrian of Australia. Palaeontology, 36:549–592.Google Scholar
Müller, K. J., and Hinz-Schallreuter, I. 1998. Internal structure of Cambrian conodonts. Journal of Paleontology, 72:91–112.Google Scholar
Nitecki, M. H., Gutschick, R. C., and Repetski, J. E. 1975. Phosphatic microfossils from the Ordovician of the United States. Fieldiana, 35:1–9.Google Scholar
Ørvig, T. 1989. Histologic studies of ostracoderms, placoderms and fossil elasmobranchs. 6. Hard tissues of Ordovician vertebrates. Zoological Scripta, 18:427–446.Google Scholar
Repetski, J. E. 1978. A fish from the Upper Cambrian of North America. Science, 200:529–531.Google Scholar
Sansom, I. J., Smith, M. M., and Smith, M. P. 1996. Scales of thelodont and shark-like fishes from the Ordovician of Colorado. Nature, 379:628–630.Google Scholar
Smith, M. P., Sansom, I. J., and Repetski, J. E. 1996. Histology of the first fish. Nature, 380:702–704.Google Scholar
Turner, S. 1997. Ichthyolith Issues. International Microvertebrate Newsletter 18, June 1997, 67 p.Google Scholar
Turner, S., Kuglitsch, J. J., and Clark, D. L. 1999. Llandoverian thelodont scales from the Burnt Bluff Group of Wisconsin and Michigan. Journal of Paleontology, 73:667–676.Google Scholar
Turner, S., Kuglitsch, J. J., Clark, D. L., and Watkins, R. 1998. Lower Silurian (Aeronian) thelodont scales and conodont fauna from Wisconsin and the Michigan Upper Peninsula. Geological Society of America Abstracts with Program, 29:77.Google Scholar
Walcott, C. 1892. Notes on the discovery of a vertebrate fauna in the Silurian (Ordovician) strata. Geological Society of America Bulletin, 3:153–172.CrossRefGoogle Scholar
Webers, G. F. 1966. The Middle and Upper Ordovician conodont faunas of Minnesota. Minnesota Geological Survey Special Publication 4, 123 p.Google Scholar