Öpik, 1975 ex Calodiscinae Kobayashi, 1943] are a family of trilobites belonging to the order Agnostida that lived during the Lower Cambrian (Botomian and Toyonian).
[3] Like all Agnostida, the Calodiscidae are diminutive and the headshield (or cephalon) and tailshield (or pygidium) are of approximately the same size (or isopygous) and outline.
The central raised area of the cephalon (or glabella) has parallel sides or tapers forward, the front being rounded and expanded, and may be divided by transverse glabellar furrows.
The occipital ring is defined by a complete transverse furrow and is neither spinose nor expanded.
When present, the eye lobes are short and prominent.