[2] The exact evolutionary relationships of Productidae as well as which groups belong to this family have been a matter of extensive debate throughout much of the 20th Century, primarily due to the three genera Buxtonia, Pustula and Juresania (with the debate later expanded to their families and subfamilies) shifting in position repeatedly between phylogenies and classifications.

The emphasis on internal versus external characters to determine the systematics of these groups has largely been responsible for this: the original Treatise on Invertebrate Paleontology published in 1965 placed emphasis on internal characters (including the cardinal process) as diagnostic, whereas the 2000 revision primarily used external features and shell shape, resulting in differing classification of these clades.

In addition, the genus Setigerites (historically placed in Buxtoniinae) has features of both productids and echinoconchids, potentially being related to the common ancestor of the two families.

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 Members of this family had a deep corpus cavity (rarely moderate or shallow) and inflated ventral corpus, with rows of spines near the hinge.

[1][4] The cardinal process of productids can be split into two main types: bi-lobed or tri-lobed.