Moose in the context of "Capreolinae"

Neontology is a part of biology that, in contrast to paleontology, studies and deals with living (or, more generally, recent) organisms. It is the study of extant taxa (singular: extant taxon): taxa (such as species, genera and families) with members still alive, as opposed to (all) being extinct. For example:

• The Indian elephant (Elephas maximus) is an extant species, and the woolly mammoth (Mammuthus primigenius) is an extinct species.
• The moose (Alces alces) is an extant species, and the Irish elk (Megaloceros giganteus) is an extinct species.
• In the group of molluscs known as the cephalopods, as of 1987 there were approximately 600 extant species and 7,500 extinct species.

A taxon can be classified as extinct if it is broadly agreed or certified that no members of the group are still alive. Conversely, an extinct taxon can be reclassified as extant if there are new discoveries of living species ("Lazarus species"), or if previously known extant species are reclassified as members of the taxon.

The American bison (Bison bison; pl.: bison), commonly known as the American buffalo, or simply buffalo (not to be confused with true buffalo), is a species of bison that is endemic (or native) to North America. It is one of two extant species of bison, along with the European bison. Its historical range circa 9000 BC is referred to as the great bison belt, a tract of rich grassland spanning from Alaska south to the Gulf of Mexico, and east to the Atlantic Seaboard (nearly to the Atlantic tidewater in some areas), as far north as New York, south to Georgia, and according to some sources, further south to northern Florida, with sightings in North Carolina near Buffalo Ford on the Catawba River as late as 1750.

Two subspecies or ecotypes have been described: the plains bison (B. b. bison), smaller and with a more rounded hump; and the wood bison (B. b. athabascae), the larger of the two and having a taller, square hump. Furthermore, the plains bison has been suggested to consist of a northern plains (B. b. montanae) and a southern plains (B. b. bison) subspecies, bringing the total to three. However, this is generally not supported. The wood bison is one of the largest wild species of extant bovid in the world, surpassed only by the Asian gaur. Among extant land animals in North America, the bison is the heaviest and the longest, and the second tallest after the moose.

A deer (pl.: deer) or true deer is a hoofed ruminant ungulate of the family Cervidae (informally the deer family). Cervidae is divided into subfamilies Cervinae (which includes, among others, muntjac, elk (wapiti), red deer, and fallow deer) and Capreolinae (which includes, among others reindeer (caribou), white-tailed deer, roe deer, and moose). Male deer of almost all species (except the water deer), as well as female reindeer, grow and shed new antlers each year. These antlers are bony extensions of the skull and are often used for combat between males.

The musk deer (Moschidae) of Asia and chevrotains (Tragulidae) of tropical African and Asian forests are separate families that are also in the ruminant clade Ruminantia; they are not especially closely related to Cervidae.

The brown bear (Ursus arctos) is a large bear native to Eurasia and North America. Of the land carnivorans, it is rivaled in size only by its closest relative, the polar bear, which is much less variable in size and slightly bigger on average. The brown bear is a sexually dimorphic species, as adult males are larger and more compactly built than females. The fur ranges in color from cream to reddish to dark brown. It has evolved large hump muscles, unique among bears, and paws up to 21 cm (8.3 in) wide and 36 cm (14 in) long, to effectively dig through dirt. Its teeth are similar to those of other bears and reflect its dietary plasticity.

Throughout the brown bear's range, it inhabits mainly forested habitats in elevations of up to 5,000 m (16,000 ft). It is omnivorous, and consumes a variety of plant and animal species. Contrary to popular belief, the brown bear derives 90% of its diet from plants. When hunting, it will target animals as small as insects and rodents to those as large as moose or muskoxen. In parts of coastal Alaska, brown bears predominantly feed on spawning salmon that come near shore to lay their eggs. For most of the year, it is a usually solitary animal that associates only when mating or raising cubs. Females give birth to an average of one to three cubs that remain with their mother for 1.5 to 4.5 years. It is a long-lived animal, with an average lifespan of 25 years in the wild. Relative to its body size, the brown bear has an exceptionally large brain. This large brain allows for high cognitive abilities, such as tool use. Attacks on humans, though widely reported, are generally rare.