Antiquatonia

Antiquatonia is an extinct genus of brachiopod belonging to the order Productida and family Productidae. Specimens have been found in Carboniferous beds across many continents, suggesting the genus had a cosmopolitan distribution. Species level taxonomy of Antiquatonia is in need of revision.

Description
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. This genus had thick, halteroid ventral spines. The ears were flanked by a ridge of ventral spines, with complimentary internal lateral ridges.

Classification
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: