Fur Structure of the Mummy of a Holocene Brown Bear (Ursus arctos Linnaeus, 1758) from Permafrost Deposits of Yakutia

The fur of the mummy of an adult female brown bear (Ursus arctos) (3500-year old ‘Etherican bear’, Holocene) found in Yakutia was studied using light and scanning electron microscopy. It was compared to the fur of recent bears, showing their similarity in color, differentiation, and hair fine structure. The fur forms a coarse, tangled, and springy pelage due to polymorphism and size and dimensional characteristics of guard hairs (length and thickness, degree of development of the medulla, height and patterns of the cuticle), and wavy profile of the hair shaft. This cover effectively protects the animalꞌs body from mechanic damage due to damping and preventing skin over-hydration. The air-bearing medulla of the hairs is poorly developed, which, together with the absence of a thick underfur, reduces the heat-protective properties of the fur, which is compensated for by a significant air layer in the loose, shaggy fur made of chaotically intertwined wavy hairs.