The Lower Carboniferous (latest Mississippian) of Bear Gulch, Montana yields exceptionally preserved marine vertebrates and invertebrates in dolomitic micritic limestones. Four general palaeocommunities have been recognized, being nektonic, benthic, algal and terrestrial-dominated (Di Canzio 1978, Lund et al. 1993). The depositional environment was a low-latitude protected marine setting. Quality of fossil preservation ranges from scattered disarticulated skeletal elements to articulated material with fine details of venous system and skin pigments and soft tissue preservation in a number of invertebrates.