There are two sub-groups (“subfamilies”) within Parastenocarididae called Parastenocaridinae
nov. and Fontinalicaridinae nov. as revealed by an analysis of the descriptions of all 258 species
known at present. Of these species, 170 (= 67%) belong to Parastenocaridinae nov., 82 (= 33%)
to Fontinalicaridinae nov. Six species could not be grouped because of incomplete descriptions.
Currently there are 27 valid genera of which 17 (= 63%) belong to Parastenocaridinae nov., and
10 (= 37%) to Fontinalicaridinae nov. The two new taxa can be distinguished mainly by the male
antennules, the endopod of female leg 3, spinules on the basis of male leg 4, the female genital field, and the setation of the caudal rami. Other distinguishing characters are legs 5, as well as male leg 1 and leg 3. Fontinalicaridinae nov. can be shown to be monophyletic by the endopod of female leg 3 lacking a terminal seta and by the form of the female genital field; possible autapomorphies of Parastenocaridinae nov. are a spinule row on the basis of male leg 4, either medially or at the base of the endopod, and the arrangement of the furcal setae. A list of genera and species of the new taxa is added.
