Fur colour covers the gamut from white to black, and fur pattern from distinctive small spots, stripes to small blotches and rosettes. Most cat species are born with a spotted fur, except the jaguarundi ("Herpailurus yagouaroundi"), Asian golden cat ("Catopuma temminckii") and caracal ("Caracal caracal"). The spotted fur of lion ("Panthera leo") and cougar ("Puma concolor") cubs change to a uniform fur during their ontogeny. Those living in cold environments have thick fur with long hair, like the snow leopard ("Panthera uncia") and the Pallas's cat ("Otocolobus manul"). Those living in tropical and hot climate zones have short fur. Several species exhibit melanism with all-black individuals. In the great majority of cat species, the tail is between a third and a half of the body length, although with some exceptions, like the "Lynx" species and margay. Cat species vary greatly in body and skull sizes, and weights:  Most cat species have a haploid number of 18 or 19. Central and South American cats have a haploid number of 18, possibly due to the combination of two smaller chromosomes into a larger one. The family Felidae is part of the Feliformia, a suborder that diverged probably about into several families. The Felidae and the Asiatic linsangs are considered a sister group, which split about . The earliest cats probably appeared about . "Proailurus" is the oldest known cat that occurred after the Eocene–Oligocene extinction event about ; fossil remains were excavated in France and Mongolia's Hsanda Gol Formation. Fossil occurrences indicate that the Felidae arrived in North America earliest . This is about later than the Ursidae and the Nimravidae, and about 10 million years later than the Canidae. In the Early Miocene about , "Pseudaelurus" lived in Africa. Its fossil jaws were also excavated in geological formations of Europe's Vallesian, Asia's Middle Miocene and North America's late Hemingfordian to late Barstovian epochs. In the Early or Middle Miocene, the sabre-toothed Machairodontinae evolved in Africa and migrated northwards in the Late Miocene. With their large upper canines, they were adapted to prey on large-bodied megaherbivores.