An ancestor of a preserved witness is a witness from which it was directly or indirectly copied. It may be extant or lost. The youngest ancestor of a witness is its exemplar; on the other hand its earliest ancestor that can be reconstructed from all preserved witnesses is called the archetype. In the ideal situation of a tradition without contamination, all ancestors of a witness are in a series of always one exemplar until the archetype is reached. With contamination the situation becomes more complicated, as one manuscript can be copied on several exemplars, or at least receive some readings from different ancestors.
The antonym to 'ancestor' is 'descendant'. Compare the similar distinction between exemplar and copy, which, in contrast to the former two terms, may not have intermediate witnesses between the two.
In other languages
DE: Vorfahre
FR: ancêtre
IT: antenato
PR