It has always been known that THEUNIS JANSZ.PIER was born circa 1600. Chris Brooks and I researched and found Theunis' baptism. His parents' names are now known!
We found a great deal on the family -- and our jointly authored article Origins of the Pier Family in the Netherlands and an Update of Their Connection to the Ostrander Family has full details and corrections of many commonly held (but incorrect) assumptions of the various Teunis Piers. Theunis Jansz's sons Jan and Arent, were the immigrant ancestors of the PIER family in America.