The formal taxonomic category Protoctista was first proposed in the early 1860s by John Hogg, who argued that the protists should include what he saw as primitive unicellular forms of both plants and animals.
O termo Protoctista como categoría taxonómica formal foi proposto a comezos da década de 1860 por John Hogg, argumentando que nese grupo se deberían incluír as que el consideraba formas primitivas unicelulares tanto de plantas coma de animais.