2nd weirdest shark ever (behind the hammerhead shark, which has a hammer for its head).
Vullo et al., Science (2021)
When you think about sharks, you think JawsA gigantic, terrifying monster with row after row of serrated teeth and cartilage like bones. But sharks aren’t always terrifying, carnivorous lords of the sea. Sometimes they are just downright weird.
That is certainly the case with “Aquilolamna milarcae,” a newly discovered plankton-chewing beast discovered by Romain Vullo and colleagues at the Université de Rennes. On Thursday, Vullo and colleagues published a report on the strange new ocean inhabitant in the journal Science, describing the creature from fossils recovered in Mexican marine deposits.
More than 66 million years ago, during the late Cretaceous period of dinosaurs, Aquilolamna milarcae swam in the oceans and absorbed plankton. So far pedestrian, but one thing makes this shark stand out: its shape. The Aquilolamna milarcae is not a normal shark. It’s a cool shark with two giant wing-like fins.
So far so strange, but this is not only visually weird, it’s weird of one too evolutionary perspective.
In short, sharks – even modern sharks that eat plankton like the basking shark – don’t usually have fins like the Aquilolamna milarcae. Such fins are usually exclusive to fish such as manta rays and devil fish. But interestingly, the fins of the Aquilolamna milarcae shark fins are older than the evolutionary predecessors of those fish by 30 million years
In this sense, this “bizarre” shark is believed to be some sort of evolutionary experiment – perhaps a failed experiment – and provides some evidence that fins seen in other fish, such as manta rays, evolved independently, in a separate branch of shark evolution. .
Regardless, the Aquilolamna milarcae had a lot in common with manta rays. It swam lazily and had long pectoral fins and a mouth designed for filter feeding, much like basking sharks and whale sharks today.