The body length may surpasses 12 cm, which is the maximum measured from the anterior margin of the head to the posterior tip of the trunk, among the few specimens collected.

[3] The ultimate pair of appendages resembles the anterior fangs in size, shape and mechanics: they are basally very swollen and bear elongate blade-edged claws.

[1] Dedicated field campaigns carried on by different zoologists turned out often unsuccessful, while most records have been obtained by occasional findings by speleologists, amateurs and common citizens.

[1] Specimens of P. zwierleini have been found both in epigeic habitats (rocky debris, woods, maquis, pastures and also urban settlements and cultivated land) and in hypogeic sites (in natural caves, at least in the Iberian peninsula and in Sardinia, but also inside buildings, especially basements and ground floors).

Both morphological and molecular analyses suggest that P. zwierleini belongs to the so-called “blind clade” of scolopendromorph centipedes (including Plutoniumidae, Cryptopidae and Scolopocryptopidae) and is strictly related to Theatops.

[5][6][1] In the past, the evolutionary affinities of Plutonium have been a matter of speculations, within the more general debates on the evolution of the segmental anatomy of the Arthropoda.