2nd strangest shark ever (behind the hammerhead shark, which has a hammer for a head).
Vullo et al., Science (2021)
When you think of sharks, you think Kake. A giant, terrifying monster with row upon row of toothed teeth and cartilage for bones. But sharks are not always terrifying, carnivorous lords of the sea. Sometimes they are just weird.
This is certainly the case with ‘Aquilolamna milarcae’, a newly discovered plankton-eating animal discovered by Romain Vullo and colleagues from the University of Rennes. Vullo and colleagues on Thursday published a report on the strange new ocean dweller in the journal Science, describing the essence of fossils recovered in Mexican marine deposits.
More than 66 million years ago, during the late Cretaceous in the time of dinosaurs, Aquilolamna milarcae swam in the oceans and sucked down plankton. So far pedestrian, but one thing makes this shark stand out: its shape. The Aquilolamna milarcae is not a normal shark. It is a cool shark with two giant winged fins.
So far strange, but it’s visually not only strange, it’s strange of a evolutionary perspective.
In short, sharks – even modern-day sharks that resemble plankton sharks like plankton – usually do not have fins like the Aquilolamna milarcae. Such fins are mostly exclusive to fish such as manta rays and devil fish. But interestingly, the sharks’ fins of the Aquilolamna milarcae are ahead of the evolutionary predecessors of those fish. 30 million years.
In this sense, this ‘bizarre’ shark is considered an evolutionary experiment – perhaps a failed experiment – and provides evidence that fins seen in other fish such as manta rays have evolved independently, in a separate branch of evolution of sharks.
Regardless, the Aquilolamna milarcae has much in common with manta rays. It swam lazily and had long pectoral fins and a mouth designed for filter feeding, such as today’s bowls and whale sharks.