That assigned to it by Ptolemy would place it on the site of Castelsardo (province of Sassari) on the north coast of the island, and only about 30 km from Porto Torres, but this is wholly incompatible with the statements of the Itineraries, and must certainly be erroneous. Indeed, Ptolemy himself places the Tibulati or Tibulates or Tibulatii (), who must have been closely connected with the town of that name, in the extreme north of the island (Ptol. iii.
Ptolemy's assigned location for the Tibulati is incompatible with the Itineraries' statements, making it undoubtedly incorrect. Moreover, Ptolemy's own placement of the Tibulati in the northernmost part of the island suggests a close association between this group and the town of Tibulatii.