So, before the Enlightenment the THEORY about sex was that there was only one biological sex and women were just shit, malformed males. It was only during the Enlightenment (with autopsies etc) that scientists realised they'd made a mistake and there are two separate biological sexes. They were wrong about the theory. But in reality of course there were female skeletons. This is such a simplistic point I can't believe that people confuse the two. In reality, women always existed. In theory, the scientists mistakenly used to think they were just deformed males but changed that theory to reflect reality when science got better!
It's like saying germs didn't exist in the 16th century and were only invented in the victorian age. No, germs always existed. but the theory of germs wasn't developed until the mid 19th century.