Evolution
Pachystomias microdon from plate 36 of Oceanic Ichthyology by G Brown Goode and Tarleton H Bean, published 1896.
The Stomiiformes order contains 5 families, 53 genera and about 391 species (Nelson 2006).
The genus Malacosteus is considered to be part of a small group which makes up the most derived clade within the Stomiiformes (Fink 1985).
The group contains:
- Malacosteus
- Photostomias
- Pachystomias
- Aristostomias
This means that these 4 genera - containing 16 species - appeared most recently in the evolutionary timescale.
