In my "AEIOU Words in Biology" in the February 1994 Word Ways, I conjectured that the Boat-billed Heron, Cochlearius cochlearius cochlearius, was possibly unique in having the five vowels once in each of its genus, species and subspecies names. Since then i have discovered a further 51 genus/species/subspecies trinomial tautonyms from the world of birds.
Word Ways: Vol. 30
, Article 21.
Available at: https://digitalcommons.butler.edu/wordways/vol30/iss2/21