WELL, YOU CAN REST ASSURED that you haven’t had the absolute weirdest sex out there. That prize has been awarded to an ancient species of fish named Microbrachius dicki (LOL), who apparently did the deed in a way that resembled square dancing. And that’s not the only feat they can claim: the Microbrachius were also literally the first species to do it! Ever!
Somehow, scientists can figure stuff like this out by looking at fossils, and they thought they had it all figured out, and that’s when the Microbrachius fish came along and threw them for a loop. These babies threw the sex game way further back in time than contemporary science previously thought — all the way to Scotland circa 385 million years ago. Well, what Scotland would have been back then, at least.
Australian paleontologist John Long suggests that the lake-dwelling tiny fish had some long arm appendages called genital claspers that came in handy for copulating. Long describes the act thusly:
“With their arms interlocked, these fish looked more like they are square dancing the do-se-do rather than mating.” Like so:
“…so the male can get this large L-shaped sexual organ into position to dock with the female’s genital plates, which are very rough like cheese graters. They act like Velcro, locking the male organ into position to transfer sperm.”
Cheese graters? Beautiful. Hope that felt better than it sounds. These frolick-y fish are also allegedly the first species to have shown morphological differences between male and female specimens, and although their sexy time sounds like a grand ol’ time, as we know, species of fish that subsequently evolved mostly went back to external spawning as their preferred mode of mating.
The prehistoric group of fish that the Microbrachius belong to — called the Placoderms — were also reportedly the first to evolve jaws, teeth, paired hind limbs, and modern inner ears.