Thurston "The Norman" Bassett, Sir - "de Aulney" and "d'Aulney"

Two points-
1. Do we think Thurston "The Norman" Basset was the son of Fulk d'Aulney? or Robert de Banastre?
2. It seems the correct spelling is d'Aulnay.

Please check with primary sources about the spelling. Someone who knows modern French might assume they know the rules, but Norman French often used de before a vowel, where modern French would use d'.

I believe that it would be helpful if we could establish the correct father of Thurstan Banastre/Basset,
From my investigations, he should be split from the Banastre tree and join his father Fougue de Aulney.

As far as I know there is no contemporary evidence for Thurstan's father. Just theories.

Thank you Justin. If that is the case, should they not be separated until the theories are proven. I don't see having two fathers as an option as it causes confusion about the ancestors and descendants.