The book by a Bulgarian linguist Ivan Duridanov gives a good piece of information about Dacian placenames: towns, rivers, settlements. The majority of town names in the area inhabited by Dacian tribes carries the final element -dava (-deva, -daua, -daba), while Thracian names, lying to the south, mostly end in -para (-phara, -pera, -parón, etc.) ‘a village’, -bria ‘a town’ and -diza (-disza, -dizos) ‘a fortress'.
Phonetics reflects that Dacian was probably more progressive than Thracian. It did not preserve most of diphthongs, which existed in Proto-Indo-European and are observed the same in Thracian. The long [e] sound turned into [æ] and then into [a], which is absolutely strange for Thracian. As for consonants, Dacian preserved voiced and unvoiced stops (b, d, g, p, t, k) which became aspirated in Thracian.