<prompt> What is the most common type of conjoined twin?CraniopagusThoracopagusIschiopagusPygopagus  <response>: Conjoined twins or Siamese twins are monozygotic twins, formed when the twinning of the embryo occurs after 12 days of feilization. Thoracopagus- fusion of thorax most common type Xiphopagusoromphalopagus- fusion of anterior abdominal wal Pygopagus- posterior fusion Ischiopagus - caudal fusion Craniopagus- fusion of cranium Rachipagus- dorsal fusion 6 