ECHINODERM PALEOECOLOGY AND PALEOENVIRONMENTS FROM THE GLEN DEAN AND LOWER PENNINGTON (CHESTERIAN). SOUTH-CENTRAL KENTUCKY *ETTENSOHN. Frank R.. Department of Geology. University of Kentucky. Lexington. KY 40506. USA. & CHESNUT. Donald R.. Department of Geology. University of Kentucky. Lexington. KY 40506. USA. Well-preserved echinoderms belonging to approximately 50 different species are relatively common in parts of the Glen Dean and overlying lower Pennington of south-central Kentucky. Over 450 well-preserved specimens have been collected to date. Crinoids, blastoids, echinoids, ophiuroids, asteroids, and edrioasterioids are represented in the fauna. The diverse, populous faunas of these rocks also contain numerous brachiopods, bryozoans, pelecypods, gastropods, and rugosans. Echinoderms collected from these rocks in south-central Kentucky have been well- known since the early 1900's. The Glen Dean is a massive, crossbedded skeletal calcarenite, which is locally oolitic; it contains a sparse, thick-shelled fauna dominated by straparollid gastropods and the stemless crinoid Agassizocrinus. This part of the Pennington intertongues with the Glen Dean and consists of dark shale with interbedded calcarenite lenses; it contains a diverse fauna with many delicate, benthonic forms. Most of the fauna is associated with the calcarenite lenses. The Glen Dean is interpreted to represent a high-energy carbonate sand belt of migrating shoals. Because of agitation and unstable bottoms, few echinoderms other than Agassizocrinus were able to live there; the heavy construction and mobility characterizing this crinoid were apparently adaptations for such conditions. Overlying parts of the lower Pennington are interpreted to represent deeper, protected lagoonal conditions leeward of the sand belt. Calcarenite lenses on which most of the echinoderms occur appear to represent isolated shoals in the lagoon, probably derived as spillover lobes from the sand belt. Firm substrates provided by these shoals and their protected position leeward of the sandbelt seem to have provided ideal environmental conditions for proliferation of echinoderm faunas. Crinoids, blastoids, echinoids, and asteroids are largely restricted to the calcarenite lenses, whereas edrioasteroids occur both on calcarenite lenses and in intervening shales. Ophiuroids are found only on crinoid anal areas.