Specimens have been found in Carboniferous beds across many continents, suggesting the genus had a cosmopolitan distribution.

[2] Like other members of Productinae, Antiquatonia had a deep corpus cavity, a geniculate profile with long trails, and well-developed marginal structures such as ear baffles.

[1] Muir-Wood & Cooper (1960) placed Antiquatonia in the subfamily Dictyoclostinae, though later analyses would find it to belong in Productinae instead.

Leighton & Maples (2002) conducted multiple phylogenetic analyses which are strongly in agreement that Antiquatonia forms a clade with Diaphragmus and Spinocarinifera.

The results of their phylogenetic analyses are displayed in the cladogram below:[2] Productella Praewaagenoconcha Sentosia Leioproductus Spinocarinifera Diaphragmus Antiquatonia Flexaria Buxtonia Pustula Echinoconchus Echinaria Pulchratia Parajuresania