Based on the Wikipedia article linked in that comment, it refers to papyrus fragments specifically, the most recent one being from aprox. the IXth century. [1]
More recent texts were copied into more durable materials:
> By the beginning of the fourth century A.D., the most important books began to be manufactured in parchment, and works worth preserving were transferred from papyrus to parchment. [2]
By the way, I don't know enough about history or archaeology to agree or disagree with the comment, I just looked up the sources because I was also confused by the phrasing.
What exactly did you mean by this? Because it surely can't be what it sounds like...