Several linguists classify Dacian as a "satem" IE language: Russu, Rădulescu(1987), Katicic (1976) and Krizman (1976). In Crossland’s opinion (1982), both Thracian and Dacian feature one of the main satem characteristics, the change of Indo-European *k and *g to s and z. But the other characteristic satem changes are doubtful in Thracian and are not evidenced in Dacian. In any case, the satem/centum distinction, once regarded as a fundamental division between IE languages, is no longer considered as important in historical linguistics by mainstream scholars. It is now recognised that it is only one of many isoglosses in the IE zone; that languages can exhibit both types at the same time, and that these may change over time within a particular language. There is much controversy about the place of Dacian in the IE evolutionary tree. According to a dated view, Dacian derived from a Daco-Thraco-Phrygian (or "Paleo-Balkan") branch of IE. Today, the Phrygian is no longer widely seen as linked in this way to Dacian and Thracian.