DNA is "lego-like" structure from "lego"-blocks
ancient DNA is just a name of more or less long
lego DNA sequence
let's say someone in the future finds a box of lego block but does not find any of lego-blocks built toys of our times
or finds sequences only of a few blocks
what would it mean?
another thing - lego blocks are made from a pretty sturdy material (actually like DNA). However, DNA is not the only molecule that can be a template for the protein assembly - RNA can do similar job. However, RNA is extremely fragile and degrades in minutes, and therefore cannot be found in fossils. Have you seen a cake made from lego blocks made from dough and cream? How long such cake will last?
If you don't find a dough lego, can you say that it never existed?
i agree with these words from the first answer
"However, it's important to point out that the way this question is phrased makes it merely trivia, with no scientific significance."