original_query: What pottery styles were present in the sub-groups of Britain between 400 and 100 BC?
query: What pottery styles were present in the sub-groups of Britain between 400 and 100 BC?
answer: The provided text states that between 400 and 100 BC, there is evidence of emerging regional identities and a significant population increase, but it does not specify the pottery styles present in the sub-groups during that time.