From Lexicanum

The Mortis Dreadnought is a rare Space Marine Dreadnought pattern used by the Dark Angels and their successor chapters.

It is armed with a pair of heavy weapons consisting of either two Missile Launchers, two twin-linked Heavy Bolters, two twin-linked autocannons or two twin-linked lascannons.¹

Notable Mortis Dreadnoughts

• Malach - Angels of Absolution, 6th tactical company ^1-p137

Images

Forge World:

Mortis Dreadnought with Missile Launchers	Mortis Dreadnought with Lascannons

Sources

• ¹:Imperial Armour Volume Two - Space Marines and Forces of the Inquisition, p137, p142