The First Genital In An Animal Evolved From An Extra Pair Of Legs
A recent analysis of placoderm fossils — an early jawed vertebrate — shows that the animal kingdom’s first genital organ was a “clasper” that evolved from an extra set of legs, and that the first sexual mating position was likely to have been a missionary one. Above: A bull male Eastmanosteus placoderm. Placoderms were the…
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John Long & Kate Trinajstic — The Conversation