monozygotic twins whose bodies do not part fully while inutero thereby resulting in two bodies joined together that might be able to be separated by surgical means, or different forms of one body with more than the average number of appendages, or two hearts wherein organ systems are shared by the two. Commonly referred to as Siamese twins.

CONJOINED TWINS: "The conjoined twins were fortunately able to be separated following their first few weeks of life once their birth weight was stable."