Marine experts have been left gobsmacked after encountering a "very large blob" washed up on a remote beach.
The blob was revealed to be the decomposing mass of a large sea creature after officers from Marine Environmental Monitoring attended the scene at Broad Haven South in Pembrokeshire, Wales.
At an estimated length of eight metres and weight of 4000 kilograms, the animal was first thought to have been a whale due to its massive size.
However soon after arriving at the beach, marine experts realised the animal was more likely to be some form of large fish.
In a post to Facebook on February 28, the marine officers revealed the fish was most likely a basking shark – the second-biggest fish in the ocean and relative of the whale shark, which is the biggest.
"We have taken several photos of key parts and taken some samples so that we can try and confirm that it is a basking shark," the department wrote in the post.
"Basking sharks are in the waters around the British coastline, but it is rare for them to wash up in Wales."
"The basking shark is the second-largest shark with the adults grow to around 8m in length, which is possible around how long this one was when it died."
Photos showed the largely decomposed remains of the animal, including its vertebrae, which based on photos before seeing the creature, marine officers thought looked like a "large roll".
"The thing that we thought was a large roll of something turned out to be just one of its vertebrate," the post read.
When alive, the shark has a somewhat faceless appearance due to the small, wide-set disposition of its eyes.
Due to the advanced stage of decomposition, the shark's head was practically non-existent.
The agency said it was unlikely the cause of the animal's death would ever be uncovered due to how much it had decayed.
One incredible image showed a row of protruding rows of cartilage which look like teeth, but were believed to have been part of the shark's pectoral fin.
Do you have a story tip? Email: firstname.lastname@example.org.