ID Help Please

I discovered a few examples of this attractive woodland plant, growing down near the waters edge at Benholm Burn, last Sunday, the striking, feathery leaves really caught my eye. I can't think or seem to find out what the plant is. Can anybody out there help me with this one? I thought for a start they might be Winter Aconite but the leaves are much too fine, or could it possibly be one of the Cranesbills? more likely I think.

Done