A lot of attention is given to the physical attributes of the worms and ahamkara. For instance some have bones as we see with the giant bones on the moon and the smaller ones on the armour and for others chitin is mentioned (let alone the wings). However I would suggest this does not matter so much. The worm gods gave oryx the power to shape the universe as he desires. They gift the hive with the ability to define their own shape. Oryx grows wings, not a typical hive trait and we can assume that the hive in current form are vastly changed from the original Krill on the fundament. If the worm gods gave them this power then we can assume that they are capable of it too and much more besides. So in conclusion; worm, dragon, feathers, bones, chitin none of it really matters because we are talking about an alien species and trying to fit them into real world earth taxonomy wont work. They could have all these features or none. Some could choose to look one way and others another way. The only thing that connects these things is their language which is psychic in nature and transcends the death of their physical form (as with the armour pieces). I would argue they are the same psychic entity taking whatever form they please and always making pacts with other beings. The worm gods make a pact with the hive, Just as the Ahamkara or wish dragons do deals with the guardians. Perhaps they had the same dark intentions as the worm gods and that is what caused the hunt? Perhaps the guardians chose the path that the Leviathan suggested to Oryx and his sisters and killed the ahamkara rather than deal with them.