Found among sarcophagi on ancient island (4)
I believe the answer is:
iona
'island' is the definition.
(Scottish island)
'found among sarcophagi on ancient' is the wordplay.
'found among' indicates the answer is hidden within the clue.
'IONA' is hidden in the letters of 'sarcophagi on ancient'.
(Other definitions for iona that I've seen before include "Hebridean island, where in 563 St Columba founded a monastery" , "Scottish island from where Christianity spread in 563 AD" , "Scottish island noted for St Columba" , "early Christian centre" , "Hebridean island associated with St Columba" .)