Lions and tigers were extensive peak predators throughout the Late Pleistocene and essential parts of East Asian megafauna.

Cavern lions mainly occupied northern Eurasia, whereas tigers were dispersed further south.

” As dominant peak predators, lions and tigers most likely formed the evolutionary paths of other sympatric predators through both direct and indirect competitors, and affected herbivore populations through predation, given that they emerged roughly 2 million years earlier,” stated Peking University scientist Shu-Jin Luo and coworkers.

“Later, lions and tigers might have ended up being substantial rivals to one another, when lions distributed out of Africa around one million years back and started broadening their variety throughout Eurasia.”

“Today, nevertheless, their geographical varieties no longer overlap, due to comprehensive contractions that happened throughout southwest Eurasia by the early 20th century, driven by anthropogenic activities. The closest current populations are now more than 300 km apart in India.”

“In contrast, throughout the Late Pleistocene, variety overlap and interactions in between lions and tigers might have took place more regularly along a shift zone– called the lion-tiger shift belt– extending throughout Eurasia, from the Middle East through Central Asia to the Far East,” they stated.

“At the easternmost edge of this zone, the Japanese Archipelago has actually long been thought about a Late Pleistocene tiger refugium, supported by big felid subfossils generally credited to tigers, though their taxonomic identity stayed unsolved.”

To clarify the origin and evolutionary history of Japan’s Pleistocene felids, the scientists reconsidered 26 subfossil stays recuperated from numerous websites throughout the Japanese Archipelago.

“Using mitochondrial and nuclear genome hybridization capture and sequencing, paleoproteomics, Bayesian molecular dating, and radiocarbon dating, we discovered that all ancient Japanese ‘tiger’ stays yielding molecular information were, suddenly, cavern lions,” they stated.

Regardless of very low endogenous DNA material in a lot of specimens, the researchers had the ability to recuperate 5 almost total mitochondrial genomes and one partial nuclear genome.

Their phylogenetic analysis revealed that the Japanese specimens formed a well-supported monophyletic group embedded within the Late Pleistocene cavern lion family tree referred to as spelaea-1

A nuclear genome analysis of the best-preserved specimen validated this outcome, separating lion family trees from tigers.

A paleoproteomic analysis even more determined a diagnostic amino acid version in alpha-2-HS-glycoprotein that matched lions instead of tigers.

According to the group, cavern lions distributed to the Japanese Archipelago in between about 72,700 and 37,500 years earlier, when a land bridge linked northern Japan to the mainland throughout the Last Glacial duration.

The animals reached even the southwestern areas of the island chain, regardless of environments formerly believed to prefer tigers.

They existed side-by-side with wolves, brown bears, Asian black bears, and early human populations, forming an important part of the Late Pleistocene community of the island chain.

The authors recommend that the spelaea-1 cavern lions continued the Japanese Archipelago for a minimum of 20,000 years after their termination in Eurasia, and possibly more than 10,000 years after their last disappearance from eastern Beringia.

“Future reexamination of lion and tiger subfossil stays throughout mid-latitude Eurasia will be vital for clarifying types vary characteristics and dealing with the oscillations of the lion-tiger belt,” they concluded.

The research study was released January 26, 2026 in the Procedures of the National Academy of Sciences

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Xin Sun et al2026. The Japanese Archipelago protected cavern lions, not tigers, throughout the Late Pleistocene. PNAS 123 (6 ): e2523901123; doi: 10.1073/ pnas.2523901123