Ever Wonder About the First Sex Ever? Don't Get Your Hopes Up
An ancient jawed fish, placoderms, have been discovered to be the first species to engage in sexual intercourse more than 385 million years ago.
The armored prehistoric Placoderms dominated lakes, rivers and oceans for tens of millions of years. Their fossils have been found in what is now called Scotland, China, and Estonia. The various species of placoderms were rife with a number of important firsts including the following:
- They had the first jaws having evolved them from gill arches.
- They were the first to evolve pelvic fins which later became somewhat useful to tetrapods as hindlimbs.
- Some were the first to display true teeth
- Live births also probably originated with them
We can now add another bullet point to that list and it’s a doozy, They seem to be the first to fertilize eggs internally through sexual intercourse!
If you want to see what placoderm coitus looked like, check out this very safe for work video. ( the fun starts at the one minute mark)
I’m sure you noticed the two thingies that are the business-end of the male placoderm. Those bony, L-shaped doodads are called claspers. For years scientists didn’t know what they were for. They looked like little arms which is why that specific species was called Microbrachius (small armed) Dicki, Yes…Dicki. They could be as long as the male’s body which sounds impressive until you realize they were only a few centimeters long. To work, it is believed that the male and female genitals would have to lock into each other. I’m not even sure what to think about that.
Summing up the significance of these fish, lead scientist Professor John Long, from Flinders University in Australia said:
“Placoderms were once thought to be a dead-end group with no live relatives, but recent studies show that our own evolution is deeply rooted in placoderms, and that many of the features we have, such as jaws, teeth and paired limbs, first originated with this group of fishes, now, we reveal they gave us the intimate act of sexual intercourse as well.”
If you dig a little deeper than the press releases though, it turns out that this first bout of copulation was lost to evolutionary history and old-school spawning later predominated. Only later on did it re-evolve and really take off. This is a good thing (maybe) because the placoderm attempt involved a a body plan with essentially 3 sets of limbs, one set being the claspers. We may look very different if their method was the one that propagated genetically.
Still though, I don’t know about you but I keep thinking about having sex sideways and how that doesn’t look like too much fun but hey, I’m sure the first primitive Twinky wasn’t that good compared to our modern evolved one either, but it was probably still pretty tasty.
Image Credit: PA