Gigantahadrosaurus

Gigantahadrosaurus is an extinct sauropod-like long-necked hadrosaur that lived in China during the Eocene from 59 million years ago to 52 million years ago. It was about 71 feet long and may have weighed around 45 tons when fully grown, making it completely quadrupedal, unlike modern day duckbills (Charonosaurus), which had a similar-looking head. It was a herbivore that most likely had fed on ginkos and other forms of tropical plants where this dinosaur species lived in. It is unknown on why this species had became extinct, but it may have been because of the ancestors of Asian giraffe beasts, an extinct species of Opisthocoelicaudia, that had its populations recovered over millions of years and probably outcompeted Gigantahadrosaurus to extinction.