Cat eyes are about six times more light-sensitive than ours
The cat family, Felidae, counts forty-one living species, all strict meat-eaters with the most varied coat patterns of any land carnivores. They share a toolkit honed for ambush: retractable claws, a shortened skull with a crushing bite, rasping tongues, sensitive whiskers and eyes built for the dark.
Most cats hunt alone, stalking or ambushing prey. Different species have adapted to forests and savannas, deserts, wetlands and mountains, and they may be active by night, at dusk and dawn, or by day depending on what they hunt. Their bodies are lean and muscular with strong, flexible forelimbs, and they walk on their toes, with five toes in front and four behind resting on compact three-lobed pads. Claws are pushed out by muscles and pull back passively, and skin sheaths protect them in every genus except Acinonyx.
The head is a precision weapon. A rounded, shortened skull with large eye sockets holds 30 teeth, including big canines and a pair of blade-like carnassials for slicing flesh. The tongue is studded with horny papillae that scrape meat off bone and double as a grooming comb. A reflective layer behind the retina, the tapetum lucidum, makes cat eyes shine and roughly sextuples their light sensitivity compared with ours, and plentiful rod cells help them spot movement in dim light while cone cells still give colour vision by day. Whiskers above the eyes, on the cheeks and muzzle, but not under the chin, help them move in darkness and grip prey, and small cats hear high-pitched sounds well enough to locate rodents.
Classification has shifted. Reginald Innes Pocock once split living cats into three subfamilies based on the bones of the throat and the claw sheaths. Molecular studies now recognise two: Pantherinae, with five Panthera and two Neofelis species, and Felinae, holding the remaining 34 species in 12 genera, with Pocock's Acinonychinae folded in.
The first cats, Proailurus and Pseudaelurus, appeared in the Oligocene about 25 million years ago. The Pseudaelurus group gave rise both to modern cats and to the extinct sabre-toothed Machairodontinae, whose canines grew enormous. The so-called false sabre-toothed cats, the nimravids and barbourofelids, were close relatives but not true cats, and together with civets, hyenas and mongooses they fall within the Feliformia.
Source: Felidae
