Given the large number of antlings recently seen in Southern Halatali, and the existence in their midst of a tunnel opening that is blocked by an NPC (which is used for all unopened dungeon areas), I'm suspecting that there may well be a rank 35 to 45 public dungeon there involving antlings, and perhaps an antling queen NM of some sort.

A dungeon in this rank range would provide a bridge from Toto-rak (rank 25 to 35ish) to Darkhold (rank 45+), so makes a lot of sense to me.