Chadian (Osagean, Mississippian) Ammonoids

  Ammonoids are found in Chadian age rocks of the Delle Phosphatic Member of the Deseret Limestone. Those shown below are from these rocks in the Stansbury Range of eastern Tooele County.  I would like to thank Dr. Morris Petersen for showing me this locality and precisely where to find the ammonoid bearing concretions.
References: Petersen, M. S., Korn, D., and Kullman, J., 2000, The Early Mississippian (Osagean) Ammonoid Dzhaprakoceras (Cephalopoda) From Utah, Journal of Paleontology Vol. 74, no. 5, p. 853-857; Kullman, J., Korn, D., and Petersen, M. S., 2000, GONIAT Database System, version 2.90, Tubingen
Dzhaprakoceras gordoni Petersen, Korn and Kullmann 2000
a specimen from a concretion, 52mm dia.

a flattened impression from the phosphatic shale, at the same level as the concretions
  about 70mm dia.

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