"Eat your greens or you'll go extinct."
That's your new line, parents of the world, to deal with picky children - and a new study can back you up.
The largest ever ape died out 100,000 years ago, because it failed to adapt to a new diet of grass, after climate change reduced its preferred diet of fruit.
Gigantopithecus, which stood at 3m tall, lived only in the forest on a strict vegeterian diet, as found by research into slight variations in carbon isotopes in the tooth enamel of the remains.
It was threatened when the planet underwent an ice age in the Pleistocene epoch, between 2.6m to 12,000 years ago.
Herve Bocherens, a researcher at Tübingen University in Germany, said that the animal, whose closest modern cousin is the Orangutan, may have died out partly due to a refusal to adapt to a new diet of savannah grass from its preferred diet of forest fruit:
Due to its size, Gigantopithecus presumably depended on a large amount of food.
When during the Pleistocene, more and more forested area turned into savannah landscapes, there was simply an insufficient food supply.
According to the study, which is due to be published in Quaternary International, other apes and early humans managed to make the switch in diet to leaves, grass and roots, but the giant ape did not.
The study concluded:
Gigantopithecus probably did not have the same ecological flexibility and possibly lacked the physiological ability to resist stress and food shortage.