A clue to this puzzle again comes from the ancient rock record.

这个谜题的线索再次来自古老的岩石记录。

He said that while fungi are one of the more diverse groups of eukaryotes today, their ancient fossil record is " very scarce" .

他说，虽然真菌是当今最多样化的真核生物群体之一，但关于它们的古老化石记录" 非常稀少" 。

" Now we have the technology to extend this methodology to another terrestrial planet, Mars, which hosts an ancient sedimentary rock record which extends even further back in time than our own, " McMahon said in a statement.

" 现在我们拥有了将这种方法推广到另一个类地行星—火星的技术，火星上保存着一份古老的沉积岩记录，其时间甚至比我们地球的记录还要久远。"