Jerrik Dace comes equipped with either a tier 7 or tier 9 version of this longsword in The Golems of AmgarrakDLC. The version obtained is dependent on the Warden-Commander's level. The following properties may differ from those listed: armor penetration, critical chance, and damage.
The Dumat's Spine shown in the picture is made of White Steel (tier 8).
The PC and console versions differ: pc: +0.75 stamina regeneration in combat ps3xbox360: +1.5 stamina regeneration in combat
Despite the item's description, the Awakening version is made of white steel.