Though its name makes it sound like the product of SyFy Channel's creature mash-up franchise, the crocodile shark is very real. These small, spindly fish are most commonly found in tropical waters – but one just recently turned up in the UK for the first time in recorded history.

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Image: Ross Spearing/used with permission

The animal was found dead on a beach at Hope Cove near Plymouth, and after photos of it surfaced online, many commenters mistook it for a baby mako or porbeagle shark. The mixup is understandable: crocodile sharks (Pseudocarcharias kamoharai) are the smallest of the mackerel sharks – a group that contains some of the most familiar shark species, including great whites, threshers and makos.

"We regularly visit this beach and have never seen anything like this before," says local resident Steven Greenfields, who made the discovery. "My whole family was stunned as the animal had really unusual features. Despite a fair amount of fishing and swimming in the UK all my life, I have never seen any shark in UK waters other than dogfish. Because it was so unusual we consulted our local aquarium to confirm what species it was."

After reaching out to a network of experts, staff at the National Marine Aquarium (NMA) were able to confirm the ID, and many of them were equally perplexed by the sighting.

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Image: Ross Spearing/used with permission

Not only are these sharks deep-dwelling, but they are also accustomed to much warmer habitats, such as the coasts of Australia and South America. This one likely strayed into uncharted waters, and succumbed to cold shock.

"It's [probably] an isolated incident," says NMA curator James Wright. "But there have been similar stranding incidents in South Africa. This time of year though, UK waters are at their coldest so this occurrence is very unusual."

In fact, crocodile shark sightings are unusual even across their native range. Most of what we know about these mysterious creatures comes from dead specimens that were hauled up accidentally by trawlers. As for those long, flexible teeth? Our knowledge of crocodile shark ecology is sketchy at best, but scientists have found a smorgasbord of prey items in the bellies of these beasties, from shrimp and fish to squid beaks.

"The crocodile shark is too small to be valuable in fisheries," adds UK Shark Trust managing director Paul Cox. "However, they are caught, like many other sharks, as bycatch in high-seas fisheries, which will likely impact on their future status. For all sharks, but especially the less common ones, any information that we can get is useful, so it's great that this one has been reported and identified."

Local beachgoers are urged to report any shark sightings to the NMA or Shark Trust teams.

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Top header image: Ross Spearing