Scientists believe placoderms were apex predators in their day. This fish family ruled existing water sources for over seventy million years before being largely killed off in a mass extinction event that still hasn't been adequately explained. Placoderms are an important species from an evolutionary standpoint. They're thought to be the origin of paired limbs and eyes, as well as teeth, jaws, and now—penetrative sex. It may even be where we get the expression "There's plenty of fish in the sea." Or not.
Professor John Long of Flinders University, AU has speculated that these placoderms physiology prevented them from engaging in both missionary and doggy-style" positions. Instead, Microbrachius dicki engaged in side-by-side intercourse in what Professor Long calls "square-dance style." This recent development doesn't actually come from new findings, but rather, from a reexamination of old ones. Many placoderm fossils exist. However, nobody noticed the genitalia of them until more recently. I guess we can assume they were not particularly well-endowed. The fish, I mean, not the scientists.
For comment, I spoke with Breana Simmons, Associate Professor of Biology at East Georgia State College, who was not involved in this study. She remarked, "For scientists, this is a fantastic piece of evidence that will fuel further hypothesis creation and lead to a greater understanding of evolution and sexual reproduction in vertebrates. As for non-scientists, who wouldn't be interested in learning about ancient fish sex? …it might even get more people into paleontology!"
