Ancestry of a purebred animal (8)
I believe the answer is:
pedigree
'ancestry of a purebred animal' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for pedigree that I've seen before include "Genealogical table" , "Record of descent" , "Lineage of thoroughbred" , "Pure-bred animal's line of descent" , "What a mongrel doesn't have" .)