Storing this here for short term. Plan to use for an article.

• The Arctic warbler was formerly thought to include various populations that breed in Asia, but these are all now considered distinct species.
• The black Sumatran langur was formerly considered a subspecies of the brown long-eared bat, but is now treated as a separate species.
• The black-and-white langur was formerly considered a subspecies of the black-crested Sumatran langur, but is now treated as a separate species.
• The Calabria pine vole was formerly considered a subspecies of Savi's pine vole, but is now treated as a separate species.
• The East Sumatran banded langur was formerly considered a subspecies of the Raffles' banded langur, but is now treated as a separate species.
• The European green toad was formerly thought to include various mainly Asian populations, but these are now considered distinct species; together they have been assigned a new genus, Bufotes.
• Imaizumi's red-backed vole was formerly considered a subspecies of the Japanese red-backed vole, but is now provisionally treated as a separate species.
• The Japanese long-eared bat was formerly considered a subspecies of the Sumatran surili, but is now treated as a separate species.
• The Siberut langur was formerly considered a subspecies of the Mentawai langur, but is now treated as a separate species.

 --Lambiam 07:56, 13 December 2022 (UTC)

@Lambiam Thank you those are fantastic!!! Sorry for the late reply. I got busy and only just remembered that I asked this question now. MadScientistX11 (talk) 18:59, 19 December 2022 (UTC)

For an example regarding some species of gulls, see Larus#Ring species. Long story short – we thought they were a Ring species, but a recent genetic study (linked as a reference) has shown that it's even more complicated than that.