Did you know sharks lived in Earth’s ocean before dinosaurs roamed its land? It’s true! Shark relatives were around a whopping 400 million years ago—and some of them looked so strange that it’s hard to believe that they’re related to today’s shark species. For instance, the iniopterygians had large, wing-like fins growing from their necks. Some scientists believe they could fly! Xenacanth sharks had markings that looked similar to a tiger, and bodies that looked similar to an eel. Listracanthus’ also had eel-like bodies but they were covered with feathery, teeth-like formations.
Not all ancient sharks were that unusual—and some are even still around today. A great example is the sixgill shark, which is included among the species that existed before dinosaurs. Because of the six gill slits along the sides of their heads (from which they get their names), these sharks bear a resemblance to many prehistoric shark species that are now extinct. Most shark species living on Earth today have five gill slits.
Sixgills are fascinating in other ways as well: they’re the third-largest predatory shark in the world, and they’re generally found in deep water (as much as 8,000 feet below the surface!) around the world. But they’ve been sighted in water as shallow as 20 feet in Puget Sound and British Columbia—even directly below the Aquarium’s pier! Our researchers have been studying them for the past several years to learn more about this mysterious, ancient species.
Ready to learn more about sharks—including sixgills and the other species that live right here in Puget Sound? Visit the Seattle Aquarium for our Wild Sharks event, July 29–August 4! You can also discover more about all kinds of sharks with our exhibit of artwork from Ray Troll’s book, Sharkabet: A Sea of Sharks from A to Z, from now through November 3. Also, check out our sixgill sharks page for information on our exhibit and research.