... "A-Alicorns"... that is a term u-unfamiliar to me...

As for my s-species... though there are various g-genetically-modified human subspecies, they are... m-meant for colonization purposes rather than being... naturally-occurring hominid subspecies. Until... genetic modification, Homo sapiens sapiens was the s-sole extant human subspecies on T-Terra...

[Not that there's anything bad about only having one extant human subspecies, but still. Ponies must have such an interesting evolutionary history!]