[3] The name llama (also historically spelled "lama" or "glama") was adopted by European settlers from native Peruvians.

[citation needed] The 19th-century discoveries of a vast and previously unexpected extinct Paleogene fauna of North America, as interpreted by paleontologists Joseph Leidy,[11] Edward Drinker Cope,[12] and Othniel Charles Marsh, aided understanding of the early history of this family.

Llama-like animals would have been a common sight 25,000 years ago in modern-day California, Texas, New Mexico, Utah, Missouri, and Florida.

Camel-like animals have been traced back through early Miocene forms from the thoroughly differentiated, modern species.

The formation of the Isthmus of Panama three million years ago allowed camelids to spread to South America as part of the Great American Interchange, where they evolved further.

The skull generally resembles that of Camelus, with a larger brain cavity and orbits and less-developed cranial ridges due to its smaller size.

In essential structural characteristics, as well as in general appearance and habits, all the animals of this genus very closely resemble each other, so whether they should be considered as belonging to one, two, or more species is a matter of controversy among naturalists.

Many are also descended from ancestors previously domesticated, a state that tends to produce a certain amount of variation from the original type.

The vicuña lives in herds on the bleak and elevated parts of the mountain range bordering the region of perpetual snow, amidst rocks and precipices, occurring in various suitable localities throughout Peru, in the southern part of Ecuador, and as far south as the middle of Bolivia.

Vicuña fiber is extremely delicate and soft and highly valued for weaving, but the quantity that each animal produces is small.

In contrast, domesticated llamas are descended primarily from wild guanaco ancestors, although a considerable amount of hybridization between the two species has occurred.

The large intestine's role in digestion is to reabsorb water, vitamins, and electrolytes from food waste passing through it.

[26] Llamas mate in a kush (lying down) position, similar to big cats and canines, which is unusual in a large animal.

Dams (female llamas) do not lick off their babies, as they have an attached tongue that does not reach outside of the mouth more than 13 millimetres (1⁄2 inch).

Crias are typically born with all the herd's females gathering to protect against the male llamas and potential predators.

The major determining factors include feed cost, availability, nutrient balance and energy density required.

Young, actively growing llamas require a greater concentration of nutrients than mature animals because of their smaller digestive tract capacities.

Their fights are visually dramatic, characterized by spitting, ramming each other with their chests, neck wrestling, and kicking, mainly to knock the other off balance.

If one notices a strange noise or feels threatened, an alarm call - a loud, shrill sound that rhythmically rises and falls - is sent out, and all others become alert.

[39][40] They are used most commonly in the western regions of the United States, where larger predators, such as coyotes and feral dogs, are prevalent.

A gelded male of two years of age bonds closely with its new charges and is instinctively very effective in preventing predation.

Although not every llama is suited to the job, most are a viable, nonlethal alternative for reducing predation, requiring no training and little care.

[44][45] Scholar Alex Chepstow-Lusty has argued that the switch from a hunter-gatherer lifestyle to widespread agriculture was only possible because of the use of llama dung as fertilizer.

[51] Carl Troll has argued that the large numbers of llamas found in the southern Peruvian highlands were an essential factor in the rise of the Inca Empire.

[52] It is worth considering the maximum extent of the Inca Empire roughly coincided with the most significant distribution of alpacas and llamas in Pre-Hispanic America.

[53] The link between the Andean biomes of puna and páramo, llama pastoralism and the Inca state is a matter of research.

[55] Gregory de Bolivar estimated that in his day, as many as 300,000 were employed in the transport of produce from the Potosí mines alone, but since the introduction of horses, mules, and donkeys, the importance of the llama as a beast of burden has greatly diminished.

[56] According to Juan Ignacio Molina, the Dutch captain Joris van Spilbergen observed the use of hueques (possibly a llama type) by native Mapuches of Mocha Island as plow animals in 1614.

[59] The decline of hueques reached a point in the late 18th century when only the Mapuche from Mariquina and Huequén next to Angol raised the animal.

Restrictions on importation of livestock from South America due to hoof and mouth disease, combined with lack of commercial interest, resulted in the number of llamas staying low until the late 20th century.