Possible human homologue (MIM number): 163700 (trait)

Cross-species summary: Also known as Supernumerary teats, multi-nippled, polymastia and hyperthelia

Species in which this phene is found:
pig (Sus scrofa)
llama (Lama glama)
cattle (Bos taurus)
goat (Capra hircus)
sheep (Ovis aries)
rabbit (Oryctolagus cuniculus)
alpaca (Vicugna pacos)