The extinct Eurasian cave lion (Panthera spelea) and today’s African and Asian lions (Panthera leo) have been analyzed through the genomes of 12 cave lions spanning over 100,000 years. This study reveals that cave lions comprise a distinct evolutionary lineage that diverged approximately 1.7 million years ago, significantly earlier than previously believed.

Lions are among the most prevalent megacarnivores in the fossil record, with remains discovered across four continents: Africa, Europe, Asia, and the Americas.

The earliest fossils exhibiting distinct lion traits originated in East Africa around 1.9 million years ago, spreading to Syria by 1 million years ago.

These majestic creatures have been recorded in Europe since about 700,000 years ago (in Italy and Britain) and in North America for 300,000 years, possibly reaching southern North America and even parts of South America around 130,000 years ago.

Today, lions are limited to a small population in India and fragmented groups across Africa.

Evidence from skeletal remains, preserved soft tissues, and Pleistocene cave paintings suggests that the extinct late Pleistocene lions in the northern Arctic were morphologically distinct from modern lions, being larger and likely possessing lighter fur.

Despite their prominence in the Holarctic fossil record during the Late Pleistocene, cave lions went extinct approximately 13,000 to 14,000 years ago, marking them as one of the earliest casualties of the megafauna extinction.

At their peak, cave lions were among the most ecologically significant predators in the Northern Hemisphere.

“The cave lion is frequently portrayed as a larger, more robust version of modern lions,” remarked lead author Dr. David Stanton, a lecturer at Cardiff University.

“However, what our genomic analysis reveals is even more astonishing: this lineage has evolved independently for over a million years, accumulating remarkable biological traits.”

Stanton’s analysis utilized 12 cave lion genomes spanning more than 100,000 years. This research shows that modern lions and cave lions are separate evolutionary lineages, each with unique demographic histories and genetic variants. Image credit: Stanton et al., doi: 10.1016/j.cell.2026.05.007.

The research team examined 12 cave lion genomes collected over 100,000 years across Eurasia and northernmost North America, comparing them with 20 genomes from modern lions in Africa and Southern Asia.

Cave lion DNA was extracted from both dental and skeletal remains, alongside well-preserved soft tissue specimens, including two cave lion cubs from northern Siberia.

Comparing these genomes indicates that cave lions and modern lions represent distinct groups, highlighting a substantial evolutionary divide.

While earlier research indicated a more recent divergence, this study supports a much older separation, approximately 1.7 million years ago.

Interestingly, the research uncovered evidence that the two lineages occasionally interbred during periods of peak glacial expansion, allowing cave lions to migrate into areas inhabited by modern lions.

The Central East Asian cave lions, dating back around 20,000 years, contained 3.2 to 4.4 percent of the ancestors of modern lions, likely stemming from the now-extinct lion population of Southwest Asia.

The authors also identified numerous unique mutations in proteins specific to cave lions, concentrated in genes associated with brain function, vision, the circulatory system, and growth, indicating significant biological adaptations to the harsh Holarctic environment they inhabited.

“Our findings point to the impact of historical climate change on more than just habitat,” stated lead author Professor Rav Dalen, research group leader at the Stockholm Center for Paleogenetics.

“It also influenced migration and created a fleeting window for interbreeding opportunities that would not have been present otherwise.”

The team’s results are published in the journal Cell.

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David WG Stanton et al. Paleogenomes reveal evolutionary relationships between modern lions and cave lions. Cell published online on June 3, 2026. doi: 10.1016/j.cell.2026.05.007