Abstract

This paper reports the establishment of a preliminary chronostratigraphy for the dinosaur-bearing Morrison Formation and associated facies in a portion of the northeastern Bighorn Basin of Wyoming. Recent discoveries of ornithopod (Camptosaurus sp.), stegosaur, sauropod (Camarasaurus sp., and the diplodocids, Barosaurus sp. and Diplodocus sp., etc., and possibly Brachiosaurus sp.) and therpod (Allosaurus sp.) associated skeletal material from contemporary Late Jurassic-aged strata in the Bighorn Basin from sites near Shell and Thermopolis during the past several years, have again focused attention on the terrestrial Morrison Formation of the northern Rockies. We have studied the Morrison and overlying Cloverly Formations from a number of localities which are in proximity to the historic Howe dinosaur quarry³ in the northeastern Bighorn Basin, for the purpose of establishing a magnetic polarity stratigraphy and to determine depositional facies characteristics.