THE ECHINODERM FAUNA OF THE CRETACEOUS COON CREEK FORMATION

The Coon Creek fauna represents one of the most diverse and best preserved Late Cretaceous marine faunal assemblages known. While the Coon Creek locality is not well known for its echinoderm fauna, both asteroids and echinoids are represented among the varied marine groups present. The only substantive work performed on the echinoderm faunal assemblages was by Wade in his work on the locality in 1926. Wade’s faunal collection represents approximately two weeks of field work. In all, he collected four species of spatangnoid echinoids, and the isolated plates of the asteroid Metopaster tennesseensis .

In the 76 years following Wade’s original field work, a considerable number of echinoids have been collected from the Coon Creek locality. Systematic collecting in the last few decades has uncovered additional specimens of Hemiaster identified by Wade, including H. stella, H. ungula, and H. wetherbyi, as well as several specimens of two unidentified holasteroids, at least one type of cassiduloid, and one type of diadematoid echinoid (represented by isolated spines).

Since Wade’s original description of the echinoderm fauna of the Coon Creek locality little systematic work has been undertaken. While, it is obvious that there is a rich echinoid fossil record at the locality, more and better preserved material needs to be collected in order to identify and fully describe the new echinoid fauna that has been uncovered in recent years. Additionally, more work needs to be done on H. ungula, which includes a taxonomic redescription, possibly a taxonomic revision, and the selection of new specimen paratypes.

Finally, comparison of the Coon Creek echinoderm fauna with the Upper Cretaceous faunas of Texas, Mississippi, Arkansas, and Alabama should be undertaken in order to gain a clearer picture of ecological control upon echinoderm faunal composition and relationships.