It was assumed for a long time that non-human animals had sex for reproduction and nothing else. Dolphins have always been the awkward exception — they mate year-round, in same-sex pairings, outside any fertile window, and with evident persistence.
In 2022 a dissection study of bottlenose dolphin clitorises found large erectile bodies, an unusually dense supply of nerve endings, and thin skin over the surface — the same combination that in humans is understood to produce pleasure. The anatomy settled what the behaviour had suggested for fifty years.
