[1][2] Armadilliidum jerrentrupi was described as a distinct species of Armadillidium in 2008, based on specimens collected as far back as 1990.

The species is also thought to belong to the "Armadillidium fossuligerum complex", a group of 4 species (A. jerenntrupi, A. fossuligerum sensu lato, A. petralonense and A. pieperi) that occur in the southern part of the Balkan Peninsula (mainly Greece and the adjacent areas of North Macedonia and Bulgaria).

It can be separated from the latter two species by the shape of the telson (truncate instead of pointed) and from the allopatric, but extremely variable, A. fossuligerum sensu lato by the different coloration, the more slender secondary antennae, the ventral shape of the ischium of the seventh pereiopod of the male (concave in A. fossuligerum sensu lato vs straight in A. jerrentrupi) and the longer uropod-exopodites.

The frontal shield surpasses the anterior edge of the head, has a nearly straight upper margin and bears obliquely-rounded lateral angles.

The telson is conspicuously longer than wide, has nearly straight sides and a broadly truncated tip.