Echinoderm faunas of the Decatur Limestone and Ross Formation (Upper Silurian to Lower Devonian) of west-central Tennessee - BAP #388
The Decatur Limestone (Pridolian) and Ross Formation (Lochkovian), which crop out in the western valley of the Tennessee River, are a series of fossiliferous bioclastic limestones and fine-grained terrigenous clastic rocks that span the Silurian-Devonian boundary. These formations were deposited at a paleoaltitude of 20-30S on a shallow shelf bounded by the Illinois Basin to the north, the Black Warrior Basin to the south, the Nashville Dome to the east, and the Ozark Uplift and New Madrid Rift Zone to the west.
The Decatur and Ross formations contain diverse assemblages of echinoderms with a total of 38 genera and 69 species in 7 classes, with the crinoids comprising the greatest number of taxa. Of the crinoids, camerates are most diverse (16 genera, 33 species) followed by disparids (8 genera, 11 species), flexibles (4 genera, 13 species), and cladids (2 genera, 4 species). Among the other echinoderm classes, blastoids are represented by 3 genra and 3 species: rhombiferans, edrioasteroids, cyclocystoids, stylophorans, and echinoids are each represented by a single genus and species.
Craig R. Clement, Carlton E. Brett
Pages: 118 pp, 12 pls.
Issue: BAP 388
Year published: 2015