(3 tables)

The Baillie Hamilton fauna contains a mixture of both shallow water and deep water brachiopods brought together in debris flows. By using criteria such as taphonomy, abundance distribution, and the community framework concept, a total of 10 communities are recog-nized from the collection. These communities represent the northern end of the Wenlockian Cordilleran faunal belt. The Baillie Hamilton fauna belongs to the Uralian-Cordilleran Region. The high Affinity Index shared by the fauna and the coeval Eastern Great Basin fauna indicates that a gradual environmental gradient separates the Uralian-Cordilleran Region from the North American Province. Key words: Silurian, Wenlockian, brachiopods, paleoecology, paleobiogeography, community er group includes medium size and often thick-shelled forms. They are mostly disarticulated and not well pre-served, indicating a shallow-water environment with rel-atively high energy. T a p h o n o m y: Disarticulation and shell fragmentation can be used as a measure of the distance and mode of transportation. The small, thin-shelled brachiopods in the B-H fauna rarely show shell damage and usually have a relatively high articulation ratio even among forms with a weak deltidiodont type articulating mechanism. The relatively undisturbed nature of these species sug-gests that they are derived from a nearby source. They probably colonized slope and basinal environments close to the final burial site. These small shells are likely to be held in suspension in the fluid head portion of a de-bris flows during down slope transportation; thus they suffered little shell damage. The larger, thick-shelled brachiopods on the other hand are mostly disarticulat-ed and fragmentary. They bear the evident marks of more abrasive shallow-water and down slope transpor-tation