KEY TO SUBFAMILIES OF AMPHINOMIDAE SAVIGNY IN LAMARCK, 1818

REMARKS

Amphinomid subfamilies were proposed and defined by Borda et al. (2012, 2015). They were initially regarded as different clades, informally named after the body shape as fusiform vs rectangular (rectilinear). However, as indicated below, body shape changes during development and this explains why it is being regarded as an additional, non-diagnostic feature. The main difference relies in the type of branchiae, their stems, and branching pattern of branchial filaments. An additional relevant feature is the presence of cirriform branchiae along some anterior chaetigers, which is currently restricted to some archinomin genera.

1. Branchiae with single stem, branched, with filaments depressed or digitate, sometimes pinnate; single cirriform branchiae sometimes present in anterior chaetigers (body tapered or fusiform) .... Archinominae Kudenov, 1991

— Branchiae with single or double stems, with filaments digitate, never pinnate; single cirriform branchiae absent (body rectangular) ........................................................................ Amphinominae Savigny in Lamarck, 1818