Article: Morphologic variability of the genus Schwagerina in the Lower Permian Wreford Limestone of Kansas
G. A. Sanderson and G. J. Verville
Fusulinids referable to the genus Schwagerina occur in the basal part of the Threemile Limestone Member of the Permian Wreford Formation in Chase County, Kansas. Three hundred specimens from six collecting localities in four townships in Chase County were used in this study. The restricted stratigraphic range and limited geographic distribution of the fusulinid fauna within the intracratonic, cyclical succession tend to minimize the effects of diachronism, and it is presumed that the collections are approximately contemporaneous.Considerable morphologic variability is evident within the Threemile fusulinid fauna, and affinities with several previously described species of Schwagerina can be demonstrated. Studies of measurable morphologic parameters suggest that all the Wreford schwagerinids sampled are referable to a single population, and thus the validity of several established taxa is open to challenge.