Joseph Richards, s/o Thomas and Weathean Richards, b. "say" 1636, d. bet. 28 Jan 1650/51 (father's probate) and 3 Jul 1679 (mother's will).
In father's will sons are listed in order John, James, Samuel, Joseph and Benjamin. Joseph is explicitly indicated as under 21 (b. aft. 1629). It may be that his father's effective specification of his guardian in the will further indicates that he was under 14, the age where he was allowed to choose his own guardian. So, while being younger than Samuel would indicate b. aft. 1634, being under 14 would further suggest that he was b. in or aft. 1636.