The unidentified creature, measuring 6.3 metres long and two metres wide, was found on a beach in Barangay Poblacion, Cagadianao, on the Philippines’ Dinagat Islands.
The Bureau of Fisheries and Aquatic Resources, based in the capital Manila, believe the remains could be those of a sea cow.
Also known as manatees, sea cows are large marine mammals, which eat a mostly herbivorous diet.
Teodoro L Alipayo, who captured the remains on camera, said a sample has been sent to the bureau to determine the species and its cause of death.
The carcass was already significantly decomposed when surprised locals discovered it on Wednesday afternoon.