Marmots of the Alai Ridge in the early quaternary. Sourki alaïskogo khr. Epokhi rannego antropogena. [Les marmottes de la chaîne de l’Ala? au début du quaternaire].

Résumé

Remains of a zoolite (a fragment of upper jaw with an incisor and M., collection of the Institute of Zoology, Academy of Science of the Republic of Uzbekistan) that is attributed to Marmota alaica sp. nov. we earlier described were discovered during a complex studies in the ancient site Selungur on the northern slopes of the Alai ridge in the Fergana valley. Chronological identification of horizons containing fossil bone remains was carried out based on the complex studies and supported by the results of callogenic and potassium-argon analysis. The fossil bone remains are aged about 1,500,000 years old. Conducted comparative analysis showed the fossil species to be very similar to long-tailed marmot in terms of size (Marmota caudata Geoffroy, 1847). The width lis 4.5 mm, thickness - 5.5 mm. The found incisor is 0.2 mm wider l ( 4.5) than that of long-tailed marmot and has the same thickness. The fossil incisor is P 4.5 mm wide and 5 mm thick. The size is the same as size P of young long-tailed marmot (collection of the Institute of Zoology, AS RUz). The data allows attributing the described species to the ancestors of M. caudata. Obtained data also enable to outline spatial borders and time limits of geographical distribution of the described species and to show certain evolutionary alterations that were happening as a result of geological transformations throughout the Quaternary.