Pustula is an extinct genus of brachiopods which lived during the Carboniferous period.

[1] Members of the genus Pustula had a subrectangular outline with a weak ventral sulcus, minimal trails and dorsal median folds.

[1] Brunton et al. (1995) deemed Pustula to be a primitive member of the Echinoconchidae family, a placement also supported by Muir-Wood & Cooper (1960).

[2][3] Leighton & Maples (2002) conducted multiple phylogenetic analyses which are strongly in agreement that the four subfamilies Buxtoniinae, Echinoconchinae, Pustulinae and Juresaniinae form the family Echinoconchidae.

The cladogram results of their phylogenetic analyses are displayed in the cladogram below:[4] Productella Praewaagenoconcha Sentosia Leioproductus Spinocarinifera Diaphragmus Antiquatonia Flexaria Buxtonia Pustula Echinoconchus Echinaria Pulchratia Parajuresania