[2] Like other agnostids, the body of eodiscids is diminutive, the headshield (or cephalon) and tailshield (or pygidium) are of approximately same size, with 2 or 3 thoracic segments in-between, each consisting of a horizontal inner portion that abruptly passes into an inclined outer portion (fulcrate).

The central raised area of the cephalon (or glabella) is narrow, usually with parallel sides and rounded front.

The furrow between the occipital ring and the more frontal parts of the glabella are a pair of pits low on its sides beneath a large median spine extending from the glabella backwards.

The distance between the glabella and the border (or preglabellar area) is usually long.

This border has dozens of small furrows radiating inward (a so-called scrobiculate border), but this defining feature may be absent in effaced species or destroyed by poor preservation.