Complex sentence: Owl butterflies, of which there are 21 different species, are members of the genus Caligo, in the family Nymphalidae (subfamily Morphinae, tribe Brassolini), and are found in the rainforests and secondary forests of Central and South America.
Split into simpler sentences: Owl butterflies, of which there are around 20 different species, are members of the genus "Caligo", in the brush-footed butterfly family Nymphalidae. They are found in the rainforests and secondary forests of Central and South America.