Ronnie and Donnie Galyon Ronnie and Donnie Galyon Ronnie and Donnie Galyon (born October 28, 1951) are American conjoined twins. According to the 2009 "Guinness World Records", the Galyons are the oldest living set of conjoined twins in the world, and, as of 29 October 2014, possess the world record for the longest-lived conjoined twins in history when they surpassed prior record holders Giacomo and Giovanni Battista Tocci. They were born at St. Elizabeth Hospital in Dayton, Ohio, on 28 October 1951, to Wesley and Eileen Galyon; Eileen was not expecting twins. They were joined from the sternum to the groin and shared a
Monochorionic twins Monochorionic twins Monochorionic twins are monozygotic (identical) twins that share the same placenta. If the placenta is shared by more than two twins (see multiple birth), these are monochorionic multiples. Monochorionic twins occur in 0.3% of all pregnancies. 75% of monozygotic twin pregnancies are monochorionic; the remaining 25% are "dichorionic diamniotic". If the placenta divides, this takes place after the third day after fertilization. Monochorionic twins generally have two amniotic sacs (called Monochorionic-Diamniotic "MoDi"), but sometimes, in the case of monoamniotic twins (Monochorionic-Monoamniotic "MoMo"), they also share the same amniotic sac. Monoamniotic twins occur when the split takes place after