The Iberian scripts are the Paleohispanic scripts that were used to represent the extinct Iberian language. Most of them are typologically unusual in that they are semi-syllabic rather than purely alphabetic. The oldest Iberian inscriptions date to the 4th or possibly the 5th century BCE, and the latest from end of the 1st century BCE or possibly the beginning of the 1st century CE. Variants There are two main graphic as well as geographic variants in the family: Northeastern Iberian script Dual variant (4th century BCE and 3rd century BCE) (tentative) Non-dual variant (2nd century BCE and 1st century BCE) Southeastern Iberian script In the sense that the Iberian scripts are the scripts created for the Iberians to represent the Iberian language, the Greco-Iberian alphabet, a separate adaptation of the Greek alphabet, was also an Iberian script. It was used mainly in Alicante and Murcia. Likewise, neither the southwestern script, very similar to southeastern Iberian script but used for the Tartessian language, nor the Celtiberian script, a direct adaptation of the northeastern Iberian script used for the Celtiberian language, are technically Iberian scripts. The northeastern Iberian script is often known simply as the Iberian script, because it is the script of 95% of known Iberian inscriptions. These have been found mainly in the northeastern quadrant of the Iberian Peninsula, mostly along the coast from Languedoc-Roussillon to Alicante, but with a deep penetration on the Ebro valley. The southeastern Iberian script is poorly attested, and there are some gaps in the records: There are no positively identified symbols for /gu/, /do/, and /m/, for example. Unlike the northeastern Iberian script the decipherment of the southeastern Iberian script is not still closed, because there are a significant group of signs without consensus value. The southeastern inscriptions have been found mainly in the southeastern quadrant of Iberia: Eastern Andalusia, Murcia, Albacete, Alicante, and Valencia. There is substantial graphic variation in the Iberian glyphs, and over the past several decades many scholars have come to believe that, at least in northeastern Iberian script (and recently also in Celtiberian script) some of this variation is meaningful. It appears that the original simple letters were assigned specifically to the voiced consonants /b/, /d/, /g/, whereas the voiceless consonants /t/ and /k/ were derived from /d/ and /g/ syllables with the addition of a stroke. (This is the so-called dual signary model: see the image at right).