No radius remains of a fossilised creature (8)
I believe the answer is:
dinosaur
'creature' is the definition.
(dinosaur is a kind of animal)
'no radius remains of a fossilised' is the wordplay.
'no radius' anagrams to 'DINOSAUR'.
However, I am not sure how this is indicated.
Can you help me to learn more?
(Other definitions for dinosaur that I've seen before include "Reptile is around, not really" , "Extinct reptilian animals" , "Prehistoric monster found on Darius" , "Large extinct reptile" , "Beast long gone" .)