Patagotitan

Patagotitan is one of the largest known dinosaurs, making it also one of the largest land animals ever found. It was far longer, almost twice as tall and more than three times heavier than Diplodocus.

Patagotitan is a titanosaur, a type of sauropod. Not all titanosaurs were particularly large, but Patagotitan was. Its thigh bone (femur) alone was 2.38 metres long.

Other contenders for the title of world's largest dinosaur are Argentinosaurus and Puertasaurus. But these dinosaurs are only known from very fragmentary remains. In some cases, only partial bones have been found, so the size of the rest of the bone has had to be estimated.

Patagotitan is far more complete and is the one whose size scientists can be most sure of, although different methods of estimating body mass mean there is still some debate over exactly how heavy it was. The most recent estimates range from 42,500 to 71,400 kilogrammes.

Patagotitan was found at La Flecha Ranch in Patagonia, Argentina, in 2010, when a ranch worker spotted an enormous dinosaur bone poking out of the ground.

Scientists were brought in to investigate, and during digs in 2012, 2013 and 2015, they unearthed hundreds of fossil bones belonging to at least six dinosaurs, which died and were buried in three distinct floods.

The species name mayorum honours the Mayo family, the owners of the ranch, for their hospitality during the fieldwork. Their ranch is still the only location where Patagotitan fossils have been found.