Any of various extinct,often gigantic,carnivorous or herbivorous reptiles of the orders Saurischia and Ornithischia that were chiefly terrestrial and existed during the Mesozoic era.

• 恐龙一种主要生活在中生代时期的陆栖动物，是庞大的食肉或食草爬行类动物，属龙盘目与鸟盘目，已绝种。