7e26d8ac_Eng_and_Chang_Bunker__Scientific_Term
[Description] Twins are likely positioned back-to-back and usually have a posterior connecton at the rump. Occurs in almost 20% of documented cases. [Scientific Term] 
Pygopagus
C r a n i o p a g u s
T h o r a o p a g u s
P y g o p a g u s
I s c h i o p a g u s
O m p h a l o p a g u s
D i c e p h a l u s
Eng and Chang Bunker
Scientific Term