Make a mistake in recording, missing last turtle (8)
I believe the answer is:
terrapin
'missing last turtle' is the definition.
'terrapin' can be an answer for 'turtle' (terrapin is a kind of turtle). I am unsure of the 'missing last' bit.
'make a mistake in recording' is the wordplay.
'make a mistake' becomes 'err' (to err is to make an error).
'in' indicates putting letters inside.
'recording' becomes 'tapin' (I can't explain this - if you can you should give a lot more credence to this answer).
'err' going into 'tapin' is 'TERRAPIN'.
Can you help me to learn more?
(Other definitions for terrapin that I've seen before include "Water tortoise" , "Partner I found for freshwater tortoise" , "Small freshwater turtle" , "Chelonian reptile" , "Web-footed turtle" .)