The Asiatic black bear (Ursus thibetanus) is listed as Vulnerable on the IUCN Red List and is designated as a Class I endangered wildlife species in the Republic of Korea, where the Korean subspecies (U. t. ussuricus) is the subject of an ongoing reintroduction program in Jirisan National Park. Opportunities to examine post-mortem tissues from this species are correspondingly rare. We report the gross and scanning electron microscopic (SEM) morphology of the dorsal lingual surface of a single male Asiatic black bear over 30 years of age and approximately 100 kg in body mass, which died of natural causes at the Uchi Park Zoological Garden (Gwangju, Republic of Korea). The tongue was preserved in 10% neutral-buffered formalin, and six biopsy fragments (two per region) were taken from the lingual apex (Front), body (Middle), and root (Rear). Samples were dehydrated, dried, sputter-coated, and imaged at ×22, ×100, and ×300 (VEGA3, TESCAN). Three distinct topographic patterns were observed. The apex was densely covered by uniformly oriented, sharply pointed, caudally directed mechanical filiform papillae. The body retained the overall caudal orientation but the papillae were larger, broader, and more irregular, with leaf-like apical processes and visible inter-papillary fissures. The root showed sparse, markedly enlarged, flattened lamellar projections together with smooth membranous areas. The antero-posterior gradient observed in this geriatric individual is consistent with previous SEM studies of other ursids and supports the established hypothesis that lingual surface microstructure in bears reflects an omnivorous, lick-and-grasp feeding strategy. To our knowledge, this is the first SEM description of the dorsal lingual surface of an U. t. ussuricus from Korea.

Abstract
INTRODUCTION
MATERIALS AND METHODS
    Specimen
    Fixation and gross examination
    Regional sampling
    SEM preparation
    SEM imaging
RESULTS
    Gross morphology
    Lingual apex (Front)
    Lingual body (Middle)
    Lingual root (Rear)
    Anteroposterior gradient
DISCUSSION
    Comparison with other ursids
    Comparison with other Carnivora
    Functional interpretation
    Possible age-related features
    Limitations
    Conservation context and significance
CONCLUSION
DECLARATIONS
    Ethics statement
    Funding
    Conflict of interest
    Author contributions
    Data availability
ACKNOWLEDGEMENTS
REFERENCES

• Sujin Jung(Gwangju Science High School, Gwangju, Republic of Korea)
• Changmin Sung(Gwangju Uchi Zoo, Gwangju, 61028, Republic of Korea)
• Hajin Jeong(Gwangju Uchi Zoo, Gwangju, 61028, Republic of Korea)
• Juwon Kang(Gwangju Uchi Zoo, Gwangju, 61028, Republic of Korea)
• Sohee Jeong(College of Veterinary Medicine and BK21 FOUR Program, Chonnam National University, Gwangju 61186, Republic of Korea)
• Yongho Cho(College of Veterinary Medicine and BK21 FOUR Program, Chonnam National University, Gwangju 61186, Republic of Korea)
• Jaebum Kim(College of Veterinary Medicine and BK21 FOUR Program, Chonnam National University, Gwangju 61186, Republic of Korea)
• Changjong Moon(College of Veterinary Medicine and BK21 FOUR Program, Chonnam National University, Gwangju 61186, Republic of Korea)
• Seungjo Park(College of Veterinary Medicine and BK21 FOUR Program, Chonnam National University, Gwangju 61186, Republic of Korea)
• Joong-sun Kim(College of Veterinary Medicine and BK21 FOUR Program, Chonnam National University, Gwangju 61186, Republic of Korea) Corresponding author
• Jun-Gyu Park(College of Veterinary Medicine and BK21 FOUR Program, Chonnam National University, Gwangju 61186, Republic of Korea, Department of Veterinary Zoonotic Diseases, College of Veterinary Medicine, Chonnam National University, Gwangju 61186, Republic of Korea) Corresponding author
• Sang-Ik Park(College of Veterinary Medicine and BK21 FOUR Program, Chonnam National University, Gwangju 61186, Republic of Korea, Department of Veterinary Pathology, College of Veterinary Medicine and BK21 FOUR Program, Chonnam National University, Gwangju 61186, Republic of Korea)