The butterfly species scientifically known as Papilio rumanzoviamakes it relatively easy to identify male versus female as its coloring follows social norms: blue signifies it's a boy. The Daily Mail reports a student visiting the U.K.'s Butterfly World Project spotted an unusual sample of one of these lepidopterans, making a discovery that amazed scientists. It was found to be half and half.
The butterfly more colloquially known as a Scarlet Mormon was half male and half female. This condition, known as gynandromorphy, occurs when sex chromosomes failed to separate. The Daily Mail reports the chances of this happening are about one in every 10,000. On this one in particular the pink wing is on its male side and the white wing is on its female side:
Louise Hawkins, Butterfly World’s chief lepidopterist said: "I feel very privileged to have witnessed such a rare phenomenon here at Butterfly World, especially fairly early in my career.
"Many lepidopterists will go their whole career without ever seeing a gynandromorph. I am very lucky."
Due to other deformities associated with this genetic mishap, the butterfly has since died but it will be persevered for research and observation.
As rare as this observation was, BBC reported London's Natural History museum seeing a similar occurrence last year with a Papilio memnon, also known as a Great Mormon butterfly. BBC pointed out gynandromorphy is also known to occur in chickens, spiders, crabs and lobsters.