Abstract This paper describes a unique case of fusion in several bones of Mammuthus trogontherii chosaricus pes from the southeast West Siberian Plain. The fusion affected the distal ends of tibia and fibula, calcaneus and astragalus. The fusion was caused by trauma, probably by dislocation with displacement of the calcaneus and astragalus and tearing of soft tissues. As a result, a deep ankylosis caused the morphological changes of the tibia's diaphysis and distal end. X-ray study showed subtotal ossification of ankle and calcaneal-talar joints, lacking joint fissures. Signs of bone fracture healing are not apparent. The animal was injured at a young age (12–15 years). Sizes of the bones and the level of ankylosis showed that the animal died at the age of 35–40, and its death was not caused by this particular pathology.