A rare fossil discovered in Japan is the oldest known plant-eating lizard, which could shed light on an evolutionary puzzle that Charles Darwin described as an "abominable mystery, " scientists say.

一具非常稀有的化石在日本被发现，这是目前已知的最古老的食草蜥蜴。科学家们说，此发现可能解开达尔文所谓的进化难题――“令人讨厌的神秘”。