(Newser)
– He swam slowly through the seas with a tail like modern sharks and side wings that extended outward like the wings of modern birds. No wonder, then, that this bizarre creature, which died in what is now Mexico about 93 million years ago, was called an eagle shark. It is particularly suitable because the pectoral fins on this specimen – the first of its kind to be found – gave it a “wingspan” of about 6.2 feet, which eclipsed its 5.4-foot length, lead researcher Romain Vullo from the National Center for Scientific Research in France and the University of Rennes says Live Science. A quarry worker discovered the fossilized shark skeleton and soft tissue imprints in a limestone slab in the Mexican state of Nuevo León, which was once part of a vast inland sea in 2012. The species is called Aquilolamna milarcae, or the eagle shark of the Milarca Museum, where the fossil will be displayed.
It would have “a unique chimerical appearance,” says Vullo. But although it is classified as a shark, the eagle shark looked more like a type of ray than a large white. The fossil shows no signs of pelvic or dorsal fins – or teeth. “This previously unknown body plan is an unexpected evolutionary experiment with underwater flight in sharks, more than 30 million years before the appearance of the mantle and devil’s rays,” the study published on Thursday reads. Science. According to Live Science, modern elasmobranchs that eat plankton (fish with cartilage skeletons) form two groups: those with a traditional shark body and those with a flatter body, such as rays. The eagle shark is not an ancestor of rays, but it was probably a wide-mouthed filter feeder that ate on plankton, as rays do today. Vullo tells AFP that the rays replaced eagle sharks after most species disappeared about 66 million years ago. (Read more stories about discoveries.)