I forgot to check if we have the paper in the lab... tomorrow maybe...
I suppose the rostral pair of "choanae" may be something more similar to the foramen incisivum of crocodiles (Iordansky, 1973, The Skull of the Crocodilia, in Biology of the Reptilia vol 4). It may not have to do with the vomeronasal organ, which is not developed in adult archosaurs as far as I can remember.
Such foramina are also present in lots of mammals in the secondary palate.
Here you have two photos of the holotype, ULR 05 (sorry the lack of expertise with photos).