Exciting Discoveries in Paleontology: Fossil Remains of Three Hyaenodont Species Found in Miocene Deposits of Pakistan
Metapterodon anari. Image credit: Steven Jasinski / SergeyAtrox1.
“Hyaenodontids evolved alongside early carnivores like cats and dogs, dominating their ecological niches before the rise of modern mammalian predators,” said Professor Stephen Jasinski from Harrisburg University of Science and Technology.
In their latest study, Professor Jasinski and his team analyzed fossils from three distinct hyaenodont species that thrived between 14 million and 9.5 million years ago.
These remarkable specimens were unearthed from the Chinji and Nagri Formations along the Siwalik River in Pakistan.
One notable hyaenodontid, potentially identified as Megistotherium or Hyainailouros, could have reached weights of up to 500 kg—comparable to a polar bear.
Among the fossils were juvenile teeth from a young specimen whose permanent teeth had yet to emerge, complicating accurate identification.
Previously identified teeth from the Hyaenodon genus further enrich our understanding. This genus is widely known across North America, Europe, and Asia, but these are the first specimens found in this region.
These fossils represent the youngest known examples of this genus and may indicate a new species, pending further material for confirmation.
The hyaenodonts are believed to have weighed around 30 kg, comparable in size to a small gray wolf or a leopard.
Paleontologists have also identified teeth from a smaller hyaenodont genus called cyanodonts, notably Metapterodon.
Previously only identified in African fossils, the emergence of this genus during the Miocene has now been validated.
The newly named Metapterodon anari may be one of the youngest hyaenodont fossils documented to date.
“Metapterodon anari holds significant value for both its taxonomic classification and its temporal context,” stated Professor Jasinski.
“This species represents one of the last hyaenodontids and provides insights into the dynamic period when these mammalian predators faced growing competition from emerging carnivores.”
The adult size of Metapterodon anari reached approximately 15 kg, akin to a large red fox or coyote.
“The significance of these fossils extends beyond their classification to their geographical implications,” the research team emphasized.
“These findings underscore a vital connection between Africa and Europe during the Miocene, suggesting migration patterns of hyaenodonts from neighboring regions, such as China.”
“The Miocene Hyaenodonts of Pakistan provide vital data regarding the coexistence of these predators and the competitive pressures they faced.”
“All these species exhibit carnivorous traits, making meat their primary diet, which may have led to their eventual competitive exclusion by more dominant carnivores.”
These fossils also shed light on the ecological landscape of Miocene South Asia. This era was marked by cooling global temperatures and significant shifts in animal communities, laying the groundwork for contemporary ecosystems.
“Fossils do more than tell tales of ancient life; they offer insights into past biological changes and how organisms adapted,” concluded Professor Jasinski.
“Examining these specimens can provide valuable clues regarding future ecological changes and strategies for adaptation.”
The team’s findings are published in the journal PALS.
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K. Mahmoud et al. A brief description of Hyaenodonta from the mid to late Miocene deposits of the Siwalik region of Pakistan and Hyaenodonta of the Indian subcontinent. PALS published online on April 16, 2026. doi: 10.1007/s12542-025-00766-5
Source: www.sci.news