TORONTO (Reuters) - The largest heart ever seen has gone on display at Toronto’s Royal Ontario Museum, giving visitors a chance to view a hugely rare biological curiosity up close.

The organ belonged to one of two blue whales whose carcasses washed up on the shores of Trout River in Newfoundland and Labrador province three years ago.

The organ measures 5 foot (1.5 m) x 4 foot x 4 foot and would have weighed at least 400 pounds (181kg) before removal.

“Some dinosaurs, like sauropods, are longer but by weight the blue whale is the heaviest animal that has ever lived on earth and of course its heart is the biggest heart,” Burton Lim, Assistant Curator of Mammalogy at the museum, told Reuters.

Blue whale carcasses are rarely discovered, as they frequently sink into the ocean’s depths due to having comparatively less blubber than other whale species.