Robert TYDINGS was the father of a John TYDINGS baptized in 1582. John had a wife Margaret (not Ann as is commonly given) who was the father of a Richard baptized in 1625.
Whether the above Richard baptized in 1625 is identical to the Richard who was in MD by apparently 1652 is unknown. Also unclear is whether there were one or two generations of Richards in MD. IF the Richard baptized 1625 is the same one in MD, and IF there is only one generation, he would have been in his mid 40s before he started having children.
For further information on the above English TYDINGS see:
Robert W. BARNES, "British Roots of Maryland Famalies," (Baltimore, MD: Genealogical Publishing Co., Inc., 1999) where he lists the above as POSSIBLY being the same as the man in MD. There are also burial records in England which contain additional information which he does not list.
http://pweb.netcom.com/~fzsaund/tydings.html