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 proposed location for the Tibulati is inconsistent with the Itineraries' descriptions, leading to the conclusion that it must be an error. This discrepancy also suggests a relationship between the Tibulati and the town of Tibulatii, as indicated by Ptolemy's own placement.