Creature in river heartless rower traps (3,4)
I believe the answer is:
roe deer
'creature' is the definition.
(type of animal)
'river heartless rower traps' is the wordplay.
I cannot really understand how this works, but
'river' could be 'dee' (River Dee) and 'dee' is located in the answer.
This explanation may well be incorrect...
'in' is the link.
Can you help me to learn more?
(Other definitions for roe deer that I've seen before include "Hoofed animal(s)" , "Common wild animal" , "beast" , "Ruminants" , "Antlered woodland creature" .)