Abstract

Two specimens of the above species were uncovered during excavation at the Glen Elder damsitel in a layer of septarian limestone concretions 3.1 feet below the base of the Lincoln Member of the Greenhorn Limestone. The zone of concretions lies within the interval of calcareous to chalky shale, transitional between typical Graneros Shale and typical Lincoln Limestone lithologies. This is part of the section that farther south is cut out by disconformity at the Graneros-Lincoln contact. The Glen Elder section represents uninterrupted deposition, and the zone of P. wyomingense is represented in normal position, as is predictable in a conformable succession of marine rocks.

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