Is a butterfly one or two animals?
There was a paper by: Donald I. Williamson, published in the Proceedings of the National Academy of Science (PNAS) August 28, 2009 https://doi.org/10.1073/pnas.0908357106, and communicated by Lynn Margulis. 

Lynn Margulis, as a member of the National Academy of Sciences, could publish papers in PNAS without adequate peer review. Members of the academy were afforded this honor, because they have achieved the highest levels of science, and supposedly, have few peers who can review their work. 

Margulis was known for her work on the origin of mitochondria from the engulfment of prokaryotes, and also the Gaia hypothesis (that the Earth is itself, a living organism). That may have predisposed her to the ludicrous idea that butterflies were the result of some strange symbiosis from onycophorans (Velvet worms). 

The whole thing was a huge embarrassment to PNAS, and Margulis. It would never have been published if it had been objectively peer reviewed, and was formally rebutted as wrong, and without any merit whatsoever. See: https://blogs.scientificamerican.com/observations/controversial-caterpillar-evolution-study-formally-rebutted/