Fenestrate, pinnate and ctenostome bryozoans and associated barnacle borings in the Wreford Megacyclothem (Lower Permian) of Kansas, Oklahoma and Nebraska

The Lower Permian Wreford Megacyclothem in Kansas and adjacent states yields abundant fenestrate (Fenestella spinulosa, F. tenax, Minilya binodata, Polypora aestacella, P. cf. nodolinearis, Protoretepora elliptica, Septopora spinulosa) and pinnate (Acanthocladia guadalupensis, Penniretepora auernigiana, P. curvula, P. flexistriata) bryozoans, as well as rare probable threadlike ctenostomes (Condranema magna, C. parvula) and some acrothoracic barnacle borings (Bascomella gigantea, originally thought also to be a ctenostome). Wreford populations of these species are described, measured, and illustrated, thereby completing systematic treatment of the Wreford bryozoan fauna (total of 20 species), expanding morphologic understanding of several hitherto little-known species, demonstrating smaller intraspecific variabilities for the fenestrates and pinnates than was found in Wreford tubular bryozoans previously studied, and extending known stratigraphic ranges of some species into the Wolfcampian. All 13 bryozoan species described are most common in the Wreford calcareous shales (especially in northern and central Kansas); some are limited thereto, but others range also into other limestone and mudstone types. Such distribution suggests considerable variation in paleoenvironmental tolerances but clear preference for deeper (though still shallow), quiet, normal-marine, mixed-mud bottoms off-shore. In addition, fenestrates contributed substantial skeletal debris to some Wreford rocks and also participated to a small extent in baffling and stabilizing carbonate mudbanks, now chalky-limestone mounds, during part of Wreford deposition