An ancient whale-like animal may be the biggest to have ever lived

One reason dinosaurs are so popular with schoolchildren is that many of them are so extraordinarily big. , a meat-eater, was up to 12 metres long—about half the length of a tennis court—and is thought to have weighed up to 7 tonnes. Some of the herbivorous dinosaurs were bigger still: , discovered in 2014, was 37m long and may have weighed 69 tonnes.But the true giants do not live on land, where the pull of gravity imposes limits on how heavy an animal can grow. They live in the sea, where their enormous bodies can be supported by the water. The most massive animal to have ever lived is still swimming around today. The blue whale, , regularly tips the scales at over 100 tonnes. Some estimates have pegged individuals at 190 tonnes.