Introduction

Promachoteuthis sulcus (first known as Promachoteuthis sp. C on this page) is known from a single, small (25 mm ML, sex unknown) but distinctive individual from great depths in the south Atlantic Ocean.

Brief diagnosis:

A promachoteuthid...

• with nuchal fusion between head and mantle.
• with arm suckers much larger than club suckers.
• with tentacle base wider than arm base.
• with recessed club base and aboral tentacle groove.