Phyconomus belongs to the heterogeneous tribe Europini within the Monotominae. Closest relationships to other genera are unclear. There is only one species currently described: Phyconomus marinus.
This species is one of only two New World Monotomidae that have the elytral punctures not arranged in rows (Monotoma longicollis also has this character state). However, the larger size, short post-coxal lines on abdominal ventrite 1, and broadly rounded intercoxal process of Phyconomus marinus will serve to distinguish this species (Bousquet 2002a).
This species is only found under rotting kelp and beach wrack along the shores of Pacific Ocean in the United States and Mexico, specifically California and Baja California (Bousquet 2002a).
Bousquet 2002a - quick review of genus
Sen Gupta 1988 - review of morphology and comparison to other genera