The problem with studying humanity 's fossil record is that it is so sparse : a jawbone here ; a braincase there .
研究人类化石记录最大的问题是资源稀缺，总是这儿一块颚骨，那儿一块头骨。
It was also possible that the jawbone had been found by humans and its teeth used to make a necklace , he said .
也有可能是有人发现了那具下颌骨，并把它的牙齿拿来做项链，他说。
The jawbone from which he had the crucial dna extracted is now back with the rest of the unknown sailor 's remains , and there are provisional plans to bury the man in geraldton .
