Hostname: page-component-586b7cd67f-dlnhk Total loading time: 0 Render date: 2024-12-02T23:28:57.353Z Has data issue: false hasContentIssue false
  • English
  • Français

Trilobites of the Gilmore City Limestone (Mississippian) of Iowa

Published online by Cambridge University Press:  19 May 2016

David K. Brezinski
David K. Brezinski*
Affiliation:
Maryland Geological Survey, 2300 St. Paul Street, Baltimore 21218
Get access Rights & Permissions [Opens in a new window]

Abstract

Four trilobite species are present in the Gilmore City Limestone (Kinderhookian–Osagean) of Humbolt County, Iowa. The most common trilobite taxa, Perexigupyge hodgesi n. gen. and sp. and Perexigupyge gerki n. gen. and sp., make up the greatest percentage of the trilobite population. Two other species are known from fragmentary cranidia and are assigned to the genera Richterella and Proetides. Prior to the description of these forms, the only trilobite previously described or illustrated from the Gilmore City Limestone was a cranidium of Proetides insignis (Winchell) from the type area.

The Gilmore City Limestone in Humbolt County, Iowa, represents deposits associated with an oölitic sand-shoal environment, including washover-lobe and back-shoal deposits. Morphologic attributes exhibited by the Gilmore City Limestone trilobites, such as low relief and vaulting to the exoskeleton and subdued surface ornamentation, may have been adaptations that enabled them to inhabit current-swept shoal environments. Conversely, coarsely tuberculate forms may have used the tubercules as a mimic of the surrounding coarse-grained sediment or to strengthen the exoskeleton.

Type
Research Article
Information
Journal of Paleontology , Volume 62 , Issue 2 , March 1988 , pp. 241 - 245
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

Bergstrom, J. 1973. Organization, life, and systematics of trilobites. Fossils and Strata, 2, 69 p.Google Scholar
Branson, E. B., and Andrews, D. 1938. Subclass Trilobita, p. 122–133. In Branson, E. B. (ed.), Stratigraphy and Paleontology of the Lower Mississippian of Missouri, Pt. 1. University of Missouri Studies, 13.Google Scholar
Brenckle, P. L., and Groves, J. R. 1986. Calcareous foraminifers from the Humbolt Oölite of Iowa: key to early Osagean (Mississippian) correlation between eastern and western North America. Palaios, 1:561–581.Google Scholar
Brezinski, D. K. 1986a. Trilobites from the Keokuk Limestone (Mississippian) of Missouri. Annals of Carnegie Museum, 55:141–147.Google Scholar
Brezinski, D. K. 1986b. Trilobite associations from the Chouteau Formation (Kinderhookian) of central Missouri. Journal of Paleontology, 60:870–881.Google Scholar
Brezinski, D. K. 1987. Spergenaspis: a new Carboniferous trilobite genus from North America. Annals of Carnegie Museum, 56:245–251.CrossRefGoogle Scholar
Carter, J. L. 1972. Early Mississippian brachiopods from the Gilmore City Limestone of Iowa. Journal of Paleontology, 46:473–491.Google Scholar
Carter, J. L. 1983. New brachiopods from the Gilmore City Limestone (Mississippian) of north-central Iowa. Annals of Carnegie Museum, 52:59–78.Google Scholar
Chamberlain, C. K. 1969. Carboniferous trilobites: Utah species and evolution in North America. Journal of Paleontology, 43:41–68.Google Scholar
Fortey, R. A. 1974. A new pelagic trilobite from the Ordovician of Spitzbergen, Ireland and Utah. Palaeontology, 17:111–124.Google Scholar
Gerk, A. J., and Levorson, C. O. 1982. Unusual beach deposit in oölite carbonate environments Mississippian and Recent. Proceedings of the Iowa Academy of Science, 89:68–70.Google Scholar
Hahn, G., and Hahn, R. 1982. Die Trilobiten des belgischen Kohlenkalkes (Unter-Karbon). Geologica et Palaeontologica, 15:89–114.Google Scholar
Harper, J. 1977. Gastropods of the Gilmore City Limestone (Lower Mississippian) of north-central Iowa. Unpubl. Ph.D. dissertation, University of Pittsburgh, 268 p.Google Scholar
Hessler, R. R. 1962. The Lower Mississippian genus Proetides (Tril.). Journal of Paleontology, 36:811–816.Google Scholar
Hessler, R. R. 1965. The Lower Mississippian trilobites of the family Proetidae in the United States, Pt. II. Journal of Paleontology, 39:248–264.Google Scholar
McNamara, K. J., and Fordham, B. G. 1981. Mid-Cautleyan (Ashgill Series) trilobites and facies in the English Lake District. Palaeogeography, Palaeoclimatology, Palaeoecology, 34:137–161.Google Scholar
Osmolska, H. 1970. Revision of non-cyrtosymbolinid trilobites from the Tournaisian-Namurian of Eurasia. Palaeontologia Polonica, 23, 165 p.Google Scholar
Stitt, J. H. 1976. Functional morphology and life habits of the Late Cambrian trilobite Stenopilus pronus (Raymond). Journal of Paleontology, 50:561–576.Google Scholar
Walter, O. T. 1924. Trilobites of Iowa and some related Paleozoic forms. Iowa Geological Survey Annual Report, 31:167–400.Google Scholar
Westrop, S. R. 1983. The life habits of the Ordovician illaenine trilobite Bumastoides. Lethaia, 16:15–24.Google Scholar
Wilson, M. A. 1979. A new species of the trilobite Brachymetopus from the Cuyahoga Formation (Lower Mississippian) of northeastern Ohio. Journal of Paleontology, 53:221–223.Google Scholar