Original paper

A new demospongiid sponge from the Permian Park City Formation, near Park City, Utah, USA

Rigby, J. Keith; McCleary, John T.; Britt, Brooks B.


Several specimens of the new demosponge Lobatospongia nodensis, n. gen. and n. sp., have been recovered as float from the "Leonardian" Meade Peak Tongue or from lower beds of the overlying "Leonardian-Guadalupian" Franson Member in the Park City Formation, in the vicinity of the Silver King Mine, near Park City, in western Summit County, Utah, USA. The sponges are broadly and shallowly obconical with a radially lobate lateral structure and an arched upper surface perforated by several coarse and smaller exhalant oscula and more numerous and smaller inhalant ostia, all in shallow depressions. Dermal and outer endosomal parts of the skeleton, where locally preserved, are composed of tufts of fine monaxial spicules, probably oxeas, around small ostia of inhalant canals that are irregularly spaced to moderately vertically aligned on dermal surfaces of both lobes and interlobe areas. The sponges have all been replaced by silica, with some of the dermal layer and some possible endosomal skeletal structures locally preserved, but with nearly all of the interior of each specimen replaced by spheroidal clusters of radiating microcrystalline quartz or concretionary to massive chert. As a result, nature of the interior skeleton is unknown.