这是一个全球性的记录:在取自不同大陆位置的沉积标本中,同位素比率的变化非常小。
It is a global record: there is remarkably little variation in isotope ratios in sedimentary specimens taken from different continental locations.
样本当然非常小,因为标本很少而能用来做实验的样本就更少了。
The sample size is of course very small, with specimens rare and samples for experimentation rarer.
在这项最新的发表在PNAS上的研究中,科学家仔细考察了一块奇特的化石标本“小盗龙”(mircoraptor),这块化石上的四肢全部都有羽毛,有点类似两栖飞机(bi-plane)。
In the newest PNAS study, scientists examined a remarkable fossil specimen that had feathers on all four limbs, somewhat resembling a bi-plane.
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