A primordial wormhole is a wormhole that formed recently. They were capable of producing large spatial and gravitational anomalies. There are five criteria to be classified as a primordial wormhole: gravitational distortions, the shape of a Gravity well, ability to change direction, a large accumulation of Dark matter, and Tachyons.
The DMA had 4 out of the 5 criteria which led Paul Stamets to hypothesize that the DMA was a primordial wormhole. However, after a mind meld with a witness revealed there were no tachyons present, Stamets was forced to conclude this hypothesis was incorrect. (DIS: "Choose to Live")
Ruon Tarka later stated about Stamets' hypothesis "obviously, that's wrong." (DIS: "The Examples")