New genetic and proteomic analysis reveals that from 73,000 to 20,000 years ago, the Japanese archipelago was home to the cave lion (Panthera spelea). This insight contrasts with previous beliefs that the region was primarily a refuge for the Tiger (Panthera tigris).
A cave lion painted at the Chauvet Cave in France.
Lions and tigers were apex predators during the Late Pleistocene, playing vital roles in the East Asian megafauna ecosystem.
Cave lions primarily roamed northern Eurasia, whereas tigers occupied southern regions.
“Since their emergence around 2 million years ago, lions and tigers have been dominant apex predators, shaping the evolution of other carnivores and influencing herbivore populations through predation,” stated researchers Shu-Jin Luo and colleagues from Peking University.
“About a million years ago, as lions migrated from Africa, they expanded their ranges in Eurasia, becoming important competitors.”
“However, due to significant habitat contraction from anthropogenic activities in the early 20th century, their ranges no longer overlap, with the closest populations now over 300 km apart in India.”
“In contrast, during the Late Pleistocene, lions and tigers frequently coexisted within the lion-tiger transition zone, which extends from the Middle East through Central Asia to the Far East,” the researchers indicated.
The Japanese archipelago, the easternmost part of this zone, was historically viewed as a refuge for tigers, yet the identity of these big cat subfossils was uncertain.
To explore the origins and evolutionary history of Japan’s Pleistocene feline populations, researchers examined 26 subfossils unearthed from various sites in the Japanese archipelago.
“Using advanced techniques such as mitochondrial and nuclear genome hybridization, paleoproteomics, Bayesian molecular dating, and radiocarbon dating, we surprisingly discovered that all ancient remains identified as ‘tiger’ were actually cave lions,” the team said.
Despite the low endogenous DNA content in most samples, scientists successfully retrieved five near-complete mitochondrial genomes and one partial nuclear genome.
The phylogenetic analysis indicated that the Japanese specimens formed a distinct monophyletic group within the Late Pleistocene cave lion lineage, designated as Speller-1.
Nuclear genome analysis of well-preserved specimens confirmed these findings, clearly differentiating the lion lineage from tigers.
Paleoproteomic analysis identified unique amino acid variants in α-2-HS-glycoprotein associated with lions but not tigers.
The research team concluded that cave lions dispersed throughout the Japanese archipelago approximately between 72,700 and 37,500 years ago, facilitated by a land bridge connecting northern Japan to the mainland during the last ice age.
They inhabited areas previously believed to favor tigers, coexisting with wolves, brown bears, black bears, and early humans, forming a crucial part of the archipelago’s Late Pleistocene ecosystem.
The authors propose that Speller-1, the cave lion, may have survived in the Japanese archipelago for at least 20,000 years after its extinction across Eurasia, outlasting its last extinction event in eastern Beringia by more than 10,000 years.
“Future studies of lion and tiger subfossil sites across mid-latitude Eurasia are essential for understanding species range dynamics and clarifying the historical interactions between lions and tigers,” the researchers concluded.
Read the full study published on January 26, 2026, in the Proceedings of the National Academy of Sciences.
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Shin San et al. 2026. “During the Late Pleistocene, the Japanese archipelago protected cave lions rather than tigers.” PNAS 123 (6): e2523901123; doi: 10.1073/pnas.2523901123
Source: www.sci.news
