LATE CRETACEOUS (MAASTRICHTIAN) OTOLITH-BASED FISHES FROM THE COON CREEK SITE IN SOUTHWEST TENNESSEE

The study and analysis of otoliths (earstones) of bony fishes from the Late Cretaceous (Maastrichtian) Coon Creek type section provide pertinent information not available solely on the basis of skeletal fish remains. Although otolith studies from the site have been limited in number and scope, ten otolith-based fishes representing at least nine families have been recognized. The otolith-based assemblage includes an albulid (bonefish), a pterothrissid (bonefish), a congrid (conger eel), an ariid (sea catfish), a chlorophthalmid (greeneyes), a trachichthyid (roughies), two apogonids (cardinal fishes), a pempherid (sweepers), and an unknown perciform. Several of the otolith-based fishes (apogonids, pempherid, and perciform) provide further evidence for the early evolution of the Perciformes in the Cretaceous rather the traditionally-accepted Early Cenozoic explosive radiation and speciation. The otolith-based fishes indicate a shallow, marine environment probably inner to middle shelf with tropical to subtropical conditions. Several of the forms, such as the albulid and pterothrissid, suggest inner neritic and possibly estuarine conditions while other taxa suggest a soft substratum. Several factors seem to indicate that detailed, systematic bulk sampling and periodic, well-organized surface collecting would result in a greater diversity of otolith-based fishes at the Coon Creek type section.