postminimus

post·min·i·mus

(pōst-min'i-mŭs),
A small accessory appendage attached to the side of the fifth finger or toe; it may resemble a normal digit or be merely a fleshy mass.
[post- + L. minimus, smallest (finger)]
References in periodicals archive ?
An additional element (po, table 1) at the postaxial end of the digital arch may represent an atavistic postminimus; such an element is standard in many Paleozoic amphibians (e.g., Eryops), some hynobiids, and the cryptobran chid Andrias.