China importing a new European mammal (7)
I believe the answer is:
manatee
'mammal' is the definition.
(manatee is a kind of mammal)
'china importing a new european' is the wordplay.
'china' becomes 'mate' ('China plate' is rhyming slang for 'mate').
'importing' indicates putting letters inside.
'a new' becomes 'an' (I've seen this in other clues).
'european' becomes 'e' (abbreviation e.g. EU).
'mate' going around 'an' is 'manate'.
'manate'+'e'='MANATEE'
(Other definitions for manatee that I've seen before include "big creature" , "To find sea cow" , "Large swimmer" , "rare sea mammal" , "Sea denizen" .)