Individual marks heralding a third in Linguistics (3)
I believe the answer is:
man
'individual' is the definition.
(I know that man is a type of Animalia)
'marks heralding a third in linguistics' is the wordplay.
'marks' becomes 'M' (former German currency).
'heralding' says to put letters next to each other (some letters come before others).
'third in linguistics' becomes 'n' (3rd letter of 'linguistics').
'm'+'a'+'n'='MAN'
(Other definitions for man that I've seen before include "race" , "Where people compete to win TT" , "Geezer" , "Dude" , "Staff the island" .)