Scientists out of Australia believe they have discovered the first animal to have ever had sex.
The Microbrachius dicki, of the placoderm species, were armored fish that lived in the waters near Scotland and appear to be the oldest known animal with reproductive organs necessary for sex, as was found by studying fossils.
"The very first act of copulation was done sideways, square-dance style," John Long, professor of palaeontology at Flinders University in Adelaide, said to The Guardian. The animals performed sex this way because of the odd shape of their reproductive organs; the male had an L-shaped sex organ and the female a cheese grater-like organ, according to Long. The male reportedly had small, bony arms meant for grasping the female during intercourse.
The animals lived as long as 430 million years ago and went extinct around 360 million years ago.
The original study can be found in the journal Nature.