The coal-dwelling beast that may be the ancient ancestor of the modern hippopotamus

Nature · Published 3 October 2026 Swipe more like this →

In short: Named for the coal beds where its fossils were first unearthed, Anthracotherium was a widespread genus of artiodactyls that roamed Eurasia and beyond for millions of years. These creatures, which share striking anatomical similarities with modern hippos, offer a fascinating glimpse into the evolutionary history of the Whippomorpha clade.

The name Anthracotherium is derived from the Ancient Greek words for coal and beast, a direct reference to the lignite beds in Europe where the first specimens were discovered. Spanning from the middle Eocene to the early Miocene, this genus was remarkably successful, with a range that extended across Eurasia and reached as far as South East Asia, Egypt, India, and North America. While the species Anthracotherium magnum was comparable in size to a pygmy hippo—measuring roughly two meters in length and weighing up to 250 kilograms—the genus encompassed a variety of sizes and ecological roles.

Central to the study of these animals is their relationship to the hippopotamus. Anthracotheres are considered likely ancestors of hippos, and together they are classified within the clade Whippomorpha. Researchers identify the genus by its 44 teeth and specific dental features, including five semi-crescentic cusps on the upper molars and distinct accessory cristulids. These morphological traits have allowed scientists to categorize them into three dietary groups: leaf browsers, fruit browsers, and grazers. In the Pondaung Formation of Myanmar, species such as A. pangan and A. crassum demonstrate how these animals occupied overlapping ecological niches.

Despite being the most thoroughly studied member of the family Anthracotheriidae, much remains to be refined regarding their extinction. Evidence from Pakistan suggests that the final species within the genus vanished shortly after the beginning of the Miocene. Because their fossils are often found in coal-bearing strata, they serve as a unique bridge between the ancient Paleogene environments and the modern mammalian lineages we recognize today. Their evolutionary trajectory highlights the complex transitions that occurred as artiodactyls adapted to diverse habitats across the globe, ultimately leading to the specialized aquatic and semi-aquatic forms seen in the Whippomorpha group.

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