Panthera spelaea in the context of "Panthera"

The Late Pleistocene to the beginning of the Holocene saw the extinction of the majority of the world's megafauna, typically defined as animal species having body masses over 44 kg (97 lb), which resulted in a collapse in faunal density and diversity across the globe. The extinctions during the Late Pleistocene are differentiated from previous extinctions by their extreme size bias towards large animals (with small animals being largely unaffected), the widespread absence of ecological succession to replace these extinct megafaunal species, and the regime shift of previously established faunal relationships and habitats as a consequence. The timing and severity of the extinctions varied by region and are generally thought to have been driven by humans, climatic change, or a combination of both. Human impact on megafauna populations is thought to have been driven by hunting ("overkill"), as well as possibly environmental alteration. The relative importance of human vs climatic factors in the extinctions has been the subject of long-running controversy, though some sources suggest that most scholars support at least a contributory role of humans in the extinctions.

Major extinctions occurred in Australia-New Guinea (Sahul) beginning around 50,000 years ago and in the Americas about 13,000 years ago, coinciding in time with the early human migrations into these regions. Extinctions in northern Eurasia were staggered over tens of thousands of years between 50,000 and 10,000 years ago, while extinctions in the Americas were virtually simultaneous, spanning only 3,000 years at most. Overall, during the Late Pleistocene about 65% of all megafaunal species worldwide became extinct, rising to 72% in North America, 83% in South America and 88% in Australia, with all mammals over 1,000 kg (2,200 lb) becoming extinct in Australia and the Americas, and around 80% globally. Africa, South Asia, and Southeast Asia experienced more moderate extinctions than other regions.

The mammoth steppe, also known as steppe-tundra, was once the Earth's most extensive biome. During glacial periods in the later Pleistocene, it stretched east to west from the Iberian Peninsula in the west of Europe, then across Eurasia and through Beringia (the region including the far northeast of Siberia, Alaska and the now submerged land between them) and into the Yukon in northwest Canada; from north to south, the steppe reached from the Arctic southward to southern Europe, Central Asia and northern China. The mammoth steppe was cold and dry, and relatively featureless—though climate, topography, and geography varied considerably throughout. Certain areas of the biome, such as coastal areas, had wetter and milder climates than others. Some areas featured rivers which through erosion naturally created gorges, gulleys, or small glens. The continual glacial recession and advancement over millennia contributed more to the formation of larger valleys and different geographical features. Overall, however, the steppe is known to be flat and expansive grassland. The vegetation was dominated by palatable, high-productivity grasses, herbs and willow shrubs. Although it was primarily a Eurasian and Beringian biome, an analog of the mammoth steppe existed on the southern edge of the Laurentide ice sheet in North America as well, and contained many of the same animals such as woolly mammoths, muskoxen, scimitar cats, and caribou.

The fauna was dominated by species such as reindeer, muskox, saiga antelope, steppe bison, horses, woolly rhinoceros and woolly mammoth. These herbivores, in turn, were followed and preyed upon by various carnivores, such as wolves, brown bears, Panthera spelaea (the cave or steppe-lion), cave hyenas, wolverines, among others, as well as scimitar-toothed cats and giant short-faced bears in east Beringia (with scimitar-toothed cats also having rare records from the mammoth steppe in Eurasia).

Panthera fossilis (also known as Panthera leo fossilis or Panthera spelaea fossilis) is an extinct species of cat belonging to the genus Panthera, known from remains found in Eurasia spanning the Middle Pleistocene and possibly into the Early Pleistocene.

Although often historically considered a subspecies of the living lion (Panthera leo), Panthera fossilis is currently considered either a distinct species to be ancestral to or a chronosubspecies of Panthera spelaea (commonly known as the cave lion or steppe lion). In comparison to Late Pleistocene Panthera spelaea specimens, Panthera fossilis tends to be considerably larger, up to 400–500 kilograms (880–1,100 lb), considerably exceeding modern lions in size, and making them among the largest cats to have ever lived, along with the South American sabertooth Smilodon populator.

Cave hyenas (Crocuta (crocuta) spelaea and Crocuta (crocuta) ultima) are extinct species or subspecies of hyena known from Eurasia, which ranged from Western Europe and West Asia to eastern Siberia, East Asia and Southeast Asia during the Pleistocene epoch. They are well represented in many caves, primarily dating to the Last Glacial Period. Cave hyenas served as apex predators that preyed on large mammals (primarily large ungulates, such as wild horse, steppe bison and aurochs), and were responsible for the accumulation of hundreds of large Pleistocene mammal bones in areas including horizontal caves, sinkholes, mud pits, and muddy areas along rivers. It was one of the main apex predators of northern Eurasian ecosystems alongside the cave lion (Panthera spelaea), with the two species likely engaging in hostile conflict over carcasses. Much like African spotted hyenas, they likely lived in clans.

Often treated as subspecies or populations of the living African spotted hyena (Crocuta crocuta) to which they were closely related and heavily resembled (though considerably larger in size), genetic evidence from the nuclear genome suggests that Eurasian Crocuta populations (including the west Eurasian Crocuta crocuta spelaea and Asian Crocuta crocuta ultima) were highly genetically divergent from African populations (having estimated to have split over 1 million years ago), with evidence suggesting limited interbreeding between Eurasian cave and African spotted hyenas. Some authors have suggested that the two subspecies should be raised to species level as Crocuta spelaea and Crocuta ultima.