Conjoined twins: Allison and Amelia

Eight-month-olds Allison June and Amelia Lee Tucker were joined at the lower chest and abdomen. The two sisters shared a chest wall, diaphragm, pericardium and liver.

The two girls have an omphalopagus connection, which accounts for 33 percent of all conjoined twins, according to the University of Maryland Medical Center.

Credit: The Children's Hospital of Philadelphia video