The first autopsy in the New World is performed in 1533 on a pair of conjoined twin sisters in Santo Domingo. According to the book, Twins: Nature's Amazing Mystery, it is conducted at the request of a priest who had baptized both children but wished to determine as to whether one or two souls were involved.

A celebrated pair of omphalopagus parasiticus conjoined twins, Lazarus and Joannes Baptista (John the Baptist) Colloredo, are born on March 20, 1617 in Genua, Italy. Lazarus and his parasitic twin tour throughout Europe for most of his life (it is believed the twins die in the late 1640's or early 1650's) as detailed in the book The Two-Headed Boy & Other Medical Marvels by Jan Bonderon (Cornell University Press, 2000). Several poems and short stories are written about the pair, including this excerpt from 'Ballard of The Two Inseperable Brothers' by Martin Parker.

The first set of conjoined twins to successfully be separated was a pair of twins who were born together in Basle in 1689. Connected by a one-inch long and five-inch diameter band, they were separated although we've seen different reports as to which doctor performed the surgery. According to the Irving and Amy Wallace biography of Chang and Eng, The Two, the surgery was performed by a celebrated physician, Dr. Fatio, who supposedly employed six surgical wires to medically separate them. Dr. Nancy Segal's book, Entwined Lives, makes reference to a German physician G. König as performing the operation.