Yousuke Kaifu of the University of Tokyo was a co-writer of the study.

东京大学的海部裕介是该研究的合著者。

Kaifu said in an email, " We did not expect that we would find smaller individuals from such an old site."

海部在一封电子邮件中表示：“我们没想到会从这么古老的地方找到体型更小的个体。”