Reptiles extremely sick from black liquids (6)

I believe the answer is:

skinks

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'reptiles' is the definition.
(skink is a kind of reptile)

'extremely sick from black liquids' is the wordplay.
'extremely' suggests removing the centre (only the extremes of the word are used).
'from' means one lot of letters go next to another.
'black liquids' becomes 'inks' (ink is a kind of liquid. I am not sure about the 'black' bit.).
'sick' with its middle taken out is 'sk'.
'sk'+'inks'='SKINKS'

Can you help me to learn more?

(Another definition for skinks that I've seen is " lizards".)

I've seen this clue in the Sydney Morning Herald.

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