Marine mammal and mammoth, perhaps close up (8,4)
I believe the answer is:
elephant seal
'marine mammal' is the definition.
'elephant seal' can be an answer for 'mammal' (elephant seal is a kind of mammal). I'm unsure of the 'marine' bit.
'mammoth perhaps close up' is the wordplay.
'mammoth perhaps' becomes 'elephant' (mammoth is a kind of elephant).
'close up' becomes 'seal' (I've seen this before).
'elephant'+'seal'='ELEPHANT SEAL'
'and' acts as a link.
Can you help me to learn more?
(Other definitions for elephant seal that I've seen before include "I wallow in the drink" , "Large aquatic mammal" , "large sea creature" , "animal" , "Large marine creature" .)