Unlike other Cambrian pentastomids, it lacks vestigial trunk limbs, therefore it is likely closer to the crown-group.

A swelling of unknown function, likely akin to the "dorsal organs" of modern pentastomid larvae, occurs roughly half-way down the length of the body.

This genus, alongside other Orsten pentastomids, is likely a larval form with the adults not being preserved.

[1] Aengapentastomum derives from the Änga quarry where it was found, alongside the fact it is a pentastomid.

The species name andresi honours Dietmar Andres, who first described pentastomid fossils from the Orsten.