First Description of the Fur of Two Cubs of Fossil Cave Lion Panthera spelaea (Goldfuss, 1810) Found in Yakutia in 2017 and 2018.

The first description of well-preserved fur of one male and one female cubs of the fossil cave lion Panthera spelaea (finds of 2017-2018, Semyuelyakh River, Yakutia, Russia) is presented in comparison with the fur of two cubs (a male and a female) of the extant African lion P. leo and adult lions of both species: the color, differentiation, configuration, microstructure, and internal design of hair of different categories are considered. The coat of the cave lion is similar but not identical to that of the African lion, because it contains a high thick undercoat of spiral-shaped thick and airy down hair. This difference is most pronounced in the cave lion cubs, in which, however, the fur is not differentiated to the same extent as in the adult. The microstructure of hair is species-specific and subject to intraspecific age-related variability. Adaptive features of the hair structure in the cave lion are noted.