The Lower Carboniferous of northern Britain is dominated by non-marine sequences which yield fish and crustacean faunas. These are rarely preserved and occur in thin layers. The sedimentology of twelve shrimp-bearing localities is described, in most cases for the first time, to shed light upon the habitats occupied by eumalacostracan crustaceans during their early Carboniferous adaptive radiation. Nearly all these sequences were deposited in coastal delta-plain settings or in interdistributary bays, environments of transitional salinity. The Gullane shrimp bed, however, was laid down in a thermally stratified non-marine lake, and its sole crustacean representative, Tealliocaris, seems to have been generally confined to waters of low salinity. None of the shrimp-beds was deposited in a fully marine environment, though most show evidence of at least some marine influence. Crustacean diversity increases with salinity, and the lack of shrimps in fully marine sediments is largely due to taphonomic factors rather than an environmental control.
