Colonies are erect, bifoliate, variable in morphology, some with strap-like branches but others comprising broad, anastomosing plates. The ancestrula and early astogenetic stages have not been described. Pore chambers are apparently lacking.
Autozooids are of moderate size, 0.55-0.85 mm long by 0.25-0.30 mm wide, and approximately rhomboidal in outline shape with narrow fissures sometimes marking the zooidal boundaries. The frontal shield is cryptocystal and convex. Areolar pores open only around the edges in young zooids but divide as the frontal shield thickens and spread more or less evenly across the frontal shield in older zooids; pseudopores are lacking. The orifice is semielliptical, about 0.10 mm long by 0.14-0.12 mm wide, with a straight proximal edge formed by a lyrula-like peristomial platform that runs between slight indentations in the two proximolateral corners of the orifice.
Brooding zooids, presumed also to be autozooids, have orifices that are broader, possess more marked proximolateral indentations and lie further away from the distal end of the zooid than those of non-brooding autozooids.
Avicularia are absent.
The only bifoliate species in the Crags with which Goodonia cookae is likely to be confused is Metrarabdotos moniliferum. However, the latter species not only has more elongate autozooids but also possesses gonozooids with large perforate ovicells and avicularia.
Pliocene, Late Zanclean–Early Piacenzian, Coralline Crag Formation, including Aldeburgh Member, Suffolk, UK.
The species also occurs in the Scaldisian of The Netherlands (Lagaaij 1952, p. 126, as “Eschara” porosa).