Dizygotic twins are siblings who have shared a common uterine environment. They are due to fertilization of two different ova by different sperm. Dizygotic twins are also called fraternal twins. ... (12 Dec 1998) ... Found on http://www.encyclo.co.uk/local/20973
twins that develop from two separate oocytes fertilized at the same time; they may be quite different in physical appearance and even of opposite sexes. Found on http://www.encyclo.co.uk/local/21001