Deep-sea 'graveyard' filmed off Angola coast
13 May 2014 Last updated at 17:21 BST
The chance discovery of a deep-sea "graveyard" is helping scientists to shed light on the fate of dead ocean giants.
Footage recorded by the oil and gas industry revealed the carcasses of four large marine creatures on a small patch of seafloor off the coast of Angola.
Around the dead whale shark and three deceased rays, scavengers flocked to the food bonanza.
Researcher Dr Nick Higgs spoke to the BBC to explain what scientists had discovered.
The findings were published in the journal Plos One.