Proto-Uralic is the reconstructed language ancestral to the Uralic language family. The language was originally spoken in a small area in about 7000–2000 BCE (estimates vary), and expanded to give differentiated protolanguages. The exact location of the area or Urheimat is not known, and various strongly differing proposals have been advocated, but the vicinity of the Ural Mountains is usually assumed.
According to the traditional binary tree model, Proto-Uralic diverged into Proto-Samoyedic and Proto-Finno-Ugric. However, reconstructed Proto-Finno-Ugric differs little from Proto-Uralic, and many apparent differences follow from the methods used. Thus Proto-Finno-Ugric may not be separate from Proto-Uralic. Another reconstruction of the split of Proto-Uralic has three branches (Finno-Permic, Ugric and Samoyedic) from the start. Recently these tree-like models have been challenged by the hypothesis of larger number of protolanguages giving a "comb" rather than a tree. The protolanguages would be Sami, (Baltic-)Finnic, Mordva, Mari, Permic, Magyar, Khanti, Mansi, and Samoyedic. This order is both the order of geographical positions as well as linguistic similarity, with neighboring languages being more similar than distant ones.
Similarly to the situation for Proto-Indo-European, reconstructions of Proto-Uralic are traditionally not written in IPA but in UPA. UPA is used here, followed by the IPA equivalents between slashes (because it is a phonemic reconstruction).
Proto-Uralic had vowel harmony and a rather large inventory of vowels in initial syllables, much like the modern Finnish or Estonian system:
Sometimes a mid vowel *ë /ɤ/ is reconstructed in place of *ï, or a low back rounded *å /ɒ/ in place of *a.