Perseus Arm (and possibly also Outer Arm) space-faring predecessors of the Limners.
The Auld Limners were an unknown biological (or possibly biomachinic) species, who built a vast empire that once stretched further beyond the periphery, and they provolved a number of species, including the modern day Limners, who may have been presapient relatives of the Auld Limners. It is known that they interacted with the Soft Ones. Most xenoarchaeologists in the Current Era believe that the Auld Limners were provolved by the Soft Ones, or at least raised from a primitive level of technology. Note that the Soft Ones themselves were probably provolved by the Muuh, making the chain of provolution Muuh - Soft Ones - Auld Limners - Limners.
Auldlimnerian Epoch - Text by M. Alan Kazlev The approximately five millennium period of the Auld Limner empire, from about 25000 to 20100 BT (usually applied to the Perseus Arm only).