Panthera youngi is known from Choukoutien, northeastern China and Japan, and lived about 350,000 years ago in the Pleistocene epoch, Harington, 1969 suggested that the American lion, the Eurasian cave lion and the large Chinese "Panthera youngi" are conspecific, The American lion ("Panthera leo atrox" or "P. atrox" ) – also known as the North American lion, Naegele’s giant jaguar or American cave lion – is an extinct lion of the family Felidae, endemic to which location during the Pleistocene epoch?
Panthera youngi Panthera youngi is known from Choukoutien, northeastern China and Japan, and lived about 350,000 years ago in the Pleistocene epoch. Fossils found in Japan were originally regarded to belong to those of tigers, but being discovered later that at least some belong to lions. Harington, 1969 suggested that the American lion, the Eurasian cave lion and the large Chinese "Panthera youngi" are conspecific.
Panthera hybrid It is known that four of the five species of the "Panthera" genus, the exception being the snow leopard, "P. uncia", can hybridize with each other to produce numerous hybrids. Most hybrids would not survive in the wild due to the males being infertile, but a few (such as the Leopon) are fertile and have a chance of survival in the wild. However, recent mitochondrial genome research by Texas A&M University geneticist William Murphy et al. reveals that wild hybrids did also occur in ancient times. In snow leopards and lions, the mitochondrial genomes of both species was more similar to each other than to other Panthera species, indicating that at some point in their history, the female progeny of the male ancestors of modern snow leopards and female ancestors of modern lions interbred with male ancestors of modern snow leopards.