What was the largest living creature of the twentieth century?

The largest living creature of the twentieth century was the blue whale. This enormous baleen whale remains the largest animal known to have ever existed, surpassing even the biggest dinosaurs in confirmed body size.

Blue whales belong to the genus Balaenoptera and feed mainly by filtering krill through plates of baleen. Despite their great size, they eat relatively small prey, sometimes consuming several tonnes of krill during a feeding season. Their streamlined bodies can exceed 30 metres in length, while adults commonly weigh well over 100 tonnes.

The phrase “largest living creature” can cause confusion because some extinct animals have been proposed as rivals. Fossils of creatures such as Perucetus and giant sauropods have produced very high estimates, but those calculations are based on incomplete remains and remain debated. The blue whale’s record is supported by measurements of living or historically documented animals.

Blue whales were heavily hunted during the twentieth century, causing populations to collapse. International protection has helped them recover in some regions, but the species is still classified as endangered.