The historical stage of the development of the Turkic languages, their interconnection with the languages ​​of the Mongolian, Tungus group of languages ​​and with other unrelated languages, the history of the migration of the Turkic peoples and their language contacts with other peoples and tribes are still of great scientific interest for ethnographers, historians, and for linguists. The vocabulary of common names of the animal world in the Turkic languages ​​is represented by one of the most interesting strata of the dictionary composition, characterised by the antiquity, variety and identity of lexical units. In this article the common names of parts of the animal's body are considered within the framework of three lexical and semantic groups (hereinafter - LSG): 1) external structure, including 1.1.) Head, neck; 1.2.) Corpus; 1.3.) Limbs (outgrowths) and their types; 1.4) skin coverings and their types); 2) internal structure; 3) internal parts of a body and their types. The lexical and semantic, phonostructural features of the 12 Yakut stems have lexical parallels in other Turkic languages, as well as their semantic transitions. The article describes the attempt to determine the relation of the Yakut language to other modern Turkic languages, as well as the change in the lexical meanings ​​of the considered stems from the Pra-Türkic form to the modern ones. As a result, it is established that the material of the Yakut language is of decisive importance for the Pra-Turkic reconstruction in terms of many parameters.