TRILOBITES of Black Cat Mountain George P. Hansen

In the upper half of the collage below are two views and various magnifications of a new genus and species of Hexactinellid sponge from Black Cat Mountain,Ceratodictyella erectusrecently described by Keith Rigby. The magnifications show encrusting gastropods and bryozoans.  On the lower right is a new fluted, columnar species also recently described by Rigby who named it Ceratodictya annulata. These descriptions are given in Rigby, J.K., G.P.Hansen,

W.J. Rushlau and L.K. Burgener, 2009, "Sponges from the Devonian Haragan Formation, Coal CountyOklahoma," Oklahoma Geology Notes 69(2): 43-55.

In the lower left corner of the collage are two rather large specimens of Hindia sphaeroidalis, a spherical Demosponge. On the lower darker specimen is the base of a crinroid epizoan, shown enlarged below the photo of the sponge.

Demosponges are the largest class in the phylum Porifera. Their skeletons are made of spicules consisting of fibers of the protein spongin, silica, or a combination of these. The class contains ninety percent of all species of sponges, with many diverse orders, including all of the large sponges. Most are marine, but several inhabit freshwater. Some species are brightly colored, assume great variety in body shapes, and reproduce sexually and asexually.