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Updated: Jul 8, 2025
Systematic Assessment of Mammalian Skull Specimens for Dental and Temporomandibular Joint Pathology
Published on: August 22, 2022
Dental Anomaly in Hapalodectes dux (Hapalodectidae, Mesonychia) from the Late Paleocene of Mongolia
1Borissiak Paleontological Institute, Russian Academy of Sciences, Moscow, Russia. alopat@paleo.ru.
Abstract:
The holotype of Hapalodectes dux Lopatin, 2001 from the Upper Paleocene of Mongolia (Tsagan-Khushu locality, Naran Bulak Formation, Zhigden Member) is a lower jaw with complete dentition, showing healed alveoli in place of the right P3. Examination of the holotype using X-ray microtomography revealed a rare dental anomaly previously unknown in fossil mammals, namely the presence of the inverted (positioned upside down and rotated lingual side labially) impacted premolar inside the dentary. The cause of this anomaly may be an aberration of a tooth bud location or an injury.
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