A rare 6-foot porbeagle shark was found dead Sunday along a Massachusetts beach.

Geovani Alves found the carcass around 11:40 a.m. while paragliding, the Cape Cod Times reported. He tried pushing it back into the water, but it washed back to shore. Alves later called authorities.

The shark was found about a half mile north of Marconi Beach, according to the Atlantic White Shark Conservancy.

The shark's cause of death is unknown. The Massachusetts Division of Marine Fisheries was notified.

Porbeagle sharks can grow up to 11.5 feet and weigh up to 300 pounds, according to the Federal Wildlife Service. The species is considered vulnerable globally and critically endangered in the northeast Atlantic.