A novel species belonging to the rhinocerotid genus Epiaceratherium has been identified by paleontologists, based on skeletal evidence unearthed in the Canadian High Arctic, dating back to the Early Miocene epoch.
A life rendering of Epiaceratherium itjilik within its woodland lake environment on Devon Island; the flora and fauna depicted are informed by discoveries at the location, notably the transitional seal species Puijila darwini. Credit for the image: Julius Csotonyi.
This newly recognized rhinoceros lineage inhabited the territory that is now Canada approximately 23 million years ago, during the Early Miocene geological epoch.
Designated Epiaceratherium itjilik, this species demonstrates the closest phylogenetic ties to prior rhinoceros populations that flourished in Europe many millennia before its existence.
“While contemporary rhino populations are confined to Africa and Asia, with only five extant species, the past saw a much wider distribution across Europe and North America, evidenced by over 50 documented fossil species,” stated Dr. Danielle Fraser, affiliated with the Canadian Museum of Nature, Carleton University, and the Smithsonian National Museum of Natural History.
“The assimilation of this Arctic representative into the rhinoceros evolutionary narrative now furnishes fresh perspectives on their developmental trajectory.”
Epiaceratherium itjilik was characterized by a comparatively diminutive and slender physique, resembling the modern Indian rhinoceros in size, though conspicuously lacking any cranial horn.
The fossilized remains of this ancient creature were exhumed from sedimentary deposits within Haughton Crater on Devon Island, Nunavut, a site renowned for its rich fossil content.
“A particularly noteworthy aspect of the Arctic rhinoceros discovery is the exceptional preservation of the fossilized bones,” remarked Dr. Marisa Gilbert, also associated with the Canadian Museum of Nature.
“They exhibit three-dimensional integrity and have undergone only partial mineralization.”
“An astonishing seventy-five percent of the complete skeletal structure was recovered, a remarkable degree of completeness for fossil specimens.”
The researchers established the taxonomic placement of Epiaceratherium itjilik within the broader rhinoceros lineage through an extensive examination involving 57 other rhinoceros species, the vast majority of which are now extinct.
This investigative process involved extensive museum collection visits, meticulous review of scientific literature, and the consultation of specialized databases.
Furthermore, the research team successfully correlated the geographic distribution of each rhinocerotid species to one of five distinct continental zones.
This comprehensive undertaking entailed a detailed scoring of each species based on its provenance, employing a quantitative modeling methodology to ascertain dispersal rates among these continental regions within the family Rhinocerotidae.
The team’s analytical findings illuminate the pathways through which rhinoceroses migrated over geological timescales between North America and Europe, facilitated by the North Atlantic Land Bridge.
Prior scientific hypotheses posited that this land bridge might have served as a migratory conduit only up until approximately 56 million years ago.
However, the contemporary analysis, incorporating data from Epiaceratherium itjilik and its related taxa, suggests that intercontinental migrations from Europe to North America occurred far more recently, potentially extending into the Miocene epoch.
“The formal description of a new species is consistently a source of great excitement and valuable information,” Dr. Fraser commented.
“However, the significance of Epiaceratherium itjilik extends further, as our reconstructed evolutionary models of rhinoceroses now indicate that the North Atlantic played a substantially more pivotal role in their development than previously surmised.”
“On a wider scale, this research underscores the Arctic’s enduring capacity to yield novel insights and discoveries that enhance our comprehension of mammalian diversification across vast stretches of time.”
The study’s findings have been published in the esteemed journal Nature Ecology & Evolution.
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D. Fraser et al. Mid-Cenozoic rhinocerotid dispersal via the North Atlantic. Nat Ecol Evol, published online October 28, 2025; doi: 10.1038/s41559-025-02872-8
