Abstract

A heretofore undescribed suite of microfossils of uncertain affinities is presented from the depauperate zone of the Upper Ordovician Maquoketa Shale of eastern Iowa and western Illinois. Morphologic feature are named and the fossils are grouped into 3 new genera, Bursata, Subcylindrica, Triangulata, and 6 new species, B. iowensis, B. maquoketensis, B. bellevuensis, S. elginensis, S. laddi, and T. simplex. Ladd's previous assignment of the fossils to the phyllocarid crustaceans is reconsidered and rejected. Assignment of the fossils to a particular phylum is deferred because of difficulty in recognizing zoological affinities.

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