Barwick, S.Brown, M.2006-06-192006-06-192004European Journal of Combinatorics, 2004; 25(3):377-3820195-66981095-9971http://hdl.handle.net/2440/3549A Yoshiara family is a set of q+3 planes in PG(5,q),q even, such that for any element of the set the intersection with the remaining q+2 elements forms a hyperoval. In 1998 Yoshiara showed that such a family gives rise to an extended generalized quadrangle of order (q+1,q−1). He also constructed such a family S(〇) from a hyperoval 〇 in PG(2,q). In 2000 Ng and Wild showed that the dual of a Yoshiara family is also a Yoshiara family. They showed that if 〇 has o-polynomial a monomial and 〇 is not regular, then the dual of S(〇) is a new Yoshiara family. This article extends this result and shows that in general the dual of S(〇) is a new Yoshiara family, thus giving new extended generalized quadrangles.enJournal article002004020210.1016/j.ejc.2003.09.0070001893106000062-s2.0-084234691757218Barwick, S. [0000-0001-9492-0323]