The insides of their first three pairs of legs have a slight fold above their claws, and their eggs have processes whose terminal discs split off into thin filaments.

The species description was written by Daniel Stec, Kazuharu Arakawa, and Łukasz Michalczyk; it was published in PLOS One in February 2018.

[1] Arakawa collected ten M. shonaicus specimens in May 2016 from moss growing in his apartment building's parking lot, in Tsuruoka, Japan.

[1]: 15–16 The specific epithet, shonaicus, is named after Shōnai, which the authors describe as "the region in Japan where the new species was collected".

Their surface is covered with protruding inverted goblet-shaped platforms, whose terminal disc is surrounded by "teeth" which extend out into thin, fragile filaments.

[1]: 11–14  The most conservative marker with respect to other species in the M. hufelandi complex was 18S rRNA, which differed 0.3–3.3% from the available sequences in GenBank.