'animalculine' originates from English, specifically the word 'animalcule' plus the adjectival suffix '-ine,' where 'animalcule' meant 'a minute animal.'

'animalculine' was formed in scientific English (18th century) from 'animalcule' (from New Latin 'animalculum,' a diminutive of Latin 'animal') and became the modern adjective 'animalculine.'

Initially, it referred directly to microscopic animals and theories about them; its core meaning remains but the term is now rare/archaic in modern usage.