To correctly write the binomial nomenclature for a particular animal, you would use Genus species. Swedish scientist Linnaeus introduced binomial nomenclature as a formal system of naming species. The word 'binomial' suggest that a name of a species is composed of two parts. The first word indicates the organism's genus classification and it is always written with the capital letter. The second word indicates the name of the species within the genus and it is never written with the capital letter.
