Bate, 1862
Small animals (2-7 mm). Body wide, stout, conglobate, usually more or less depressed dorsoventrally. Pleon distinctly narrower than pereon, capable of folding under pereon. Head short, wider than pereon, with broadly rounded ventral margin (resembling anterior margin). Eyes large, occupying most of head surface, each with two dark "centres". Mouth parts in form of cone, MD elongate, with narrow incisor, mandibular palp absent in female. Maxillae with large broad lobes. Coxae free. P V and VI with ART 2 transformed into broad opercula, longer in P VI. Distal ART more or less reduced, attached to ART 2 sub-terminally in P V, mid-posteriorly in P VI. Posterior margin of ART 2 of P VI with longitudinal groove, outer surface of ART often with fissure. P VII small, but with all ART present (except Thyropus). Telson broadly triangular, fused with II+III urosomite. Very similar to Family Platyscelidae.
Five genera, 4 in South Atlantic. Parascelidae can tuck pleon under broad pereon, cover all pereopods and pleopods with broad articles 2 of pereopod V and VI, and place telson in longitudinal groove of article 2 of pereopod VI. The animal thus becomes conglobate, and can sink very rapidly - for example, to evade a predator. Because they conglobate readily in dangerous situations, they may very often be found in such configurations in samples. Besides Parascelidae, only Platyscelidae can conglobate in this way.
Genera treated:
Genus Euscelus
Genus Hemiscelus Stewart, 1913
Genus Parascelus Claus, 1879
Genus Schizoscelus Claus, 1879
Genus Thyropus Dana, 1852