The Echinoid Directory

Family Plexechinidae Mooi & David, 1996, p. 946

Diagnosis

Urechinine holasteroids with:

thin test;
orthosternous plastron (labral plate followed by single symmetrical sternal plate). Labral plate may be separated from sternal plate by ambulacral plates;
ambulacral plates I.a.4 and V.b.4 extended behind episternal plates and incorporated into subanal fasciole;
no rostral plate;
pores outside phyllodes single;
apical disc with single anterior genital plate;
periproct supramarginal; somewhat sunken.

Range

Recent; Indo-Pacific, Antarctic.