No creditable macrofossil record of the Fagaceae exists in the Cretaceous deposits and all the Cretaceous microfossil reports remain equivocal and require further study.

白垩纪尚无壳斗科可靠的大化石记录，微化石一步研究才能确定亲缘关系及古新世壳斗科已经分化出群。

In the summer of 2003 we began to zero in on one microfossil type whose complex morphological characteristics particularly intrigued us.

2003年夏天，我们开始瞄准一种微化石的型，其复杂的形态特徵特别引起我们兴趣。