“It’s really a miracle of evolution!” Well said, Matt Hooper. Sharks are indeed a phenomenon of natural selection, but the idea that they are an ancient miracle of evolution, i.e. “living fossils,” may be an outdated concept. According to a study published in the most recent edition of Nature, shark species ditched their primitive anatomies long ago. The study indicates that the body forms we see in the great whites and hammerheads of today actually represent the cutting edge of shark physiology. This reassessment of the famed ocean predators started with the discovery of a 325 million year old fossil of an ancient shark named Ozarcus mapesae.
Fossils of Ozarcus mapesae. (American Museum of Natural History)
“Sharks are traditionally thought to be one of the most primitive surviving jawed vertebrates. And most textbooks in schools today say that the internal jaw structures of modern sharks should look very similar to those in primitive shark-like fishes,” said Alan Pradel, a researcher at the American Museum of Natural History, “But we’ve found that’s not the case. The modern shark condition is very specialized, very derived, and not primitive.”
This new perception of sharks is based on the discovery of an incredibly well preserved O. mapesae skull. In the head of every fish (both sharks and bony fishes) are arches that help keep the shape of the head and gills. To the surprise of the researchers, the head arches they observed in O. mapesae looked nothing like those found in modern sharks, indicating that today’s roster of sharks is significantly more advanced than that of O. mapesae‘s era.
Ancient sharks are weird. For a serious mind blow, check out Akministion and see if you have any theories as to how the hell this bizarre tooth whorl fit into Helicoprion’s mouth. Strange sharks aren’t necessarily a thing of the past, either. The cookiecutter shark has a twisted mode of predation that will make you swim in a full suit of armor from now on.