genus
Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
of the
monophyletic
In biological cladistics for the classification of organisms, monophyly is the condition of a taxonomic grouping being a clade – that is, a grouping of organisms which meets these criteria:
# the grouping contains its own most recent co ...
bear
Bears are carnivoran mammals of the family (biology), family Ursidae (). They are classified as caniforms, or doglike carnivorans. Although only eight species of bears are extant, they are widespread, appearing in a wide variety of habitats ...
subfamily
In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end botanical subfamily names with "-oideae", and zo ...
Tremarctinae
The Tremarctinae or short-faced bears is a subfamily of Ursidae that contains one living representative, the spectacled bear (''Tremarctos ornatus'') of South America, and several extinct species from four genera: the Florida spectacled bear ( ...
, endemic to
Americas
The Americas, sometimes collectively called America, are a landmass comprising the totality of North America and South America.''Webster's New World College Dictionary'', 2010 by Wiley Publishing, Inc., Cleveland, Ohio. When viewed as a sing ...
from the
Pliocene
The Pliocene ( ; also Pleiocene) is the epoch (geology), epoch in the geologic time scale that extends from 5.33 to 2.58recent. The northern species, the Florida short-faced bear, became extinct 11,000 years ago.B. Kurten & E. Anderson (1980): Pleistocene mammals of North America, pp 1-442. Columbia University Press The sole living ''Tremarctos'' species is the South American spectacled bear. ''Tremarctos'' is also the only living genus under the Tremarctinae subfamily, with the other genera, '' Plionarctos,
Arctodus
''Arctodus'' is an extinct genus of short-faced bear that inhabited North America during the Pleistocene (~2.6 Year#mya, Mya until 12,800 years ago). There are two recognized species: the lesser short-faced bear (''Arctodus pristinus'') and the gia ...
,'' and ''
Arctotherium
''Arctotherium'' ("bear beast") is an extinct genus of the Pleistocene Tremarctinae, short-faced bears endemic to Central America, Central and South America. ''Arctotherium'' migrated from North America to South America during the Great American In ...
Tremarctos floridanus
''Tremarctos floridanus'' is an extinct species of bear in the family Ursidae, subfamily Tremarctinae. ''T. floridanus'' became extinct at the end of the last ice age, 11,000 years ago. Its fossils have been found throughout the Southeastern U ...
''Tremarctos floridanus'' bears lived in the southern parts of North America. ''Tremarctos ornatus'' however lives in South America, such as in the
Andes Mountains
The Andes ( ), Andes Mountains or Andean Mountain Range (; ) are the longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range is long and wide (widest between 18°S ...
of Peru. They also live in countries like Bolivia and Venezuela. ''Tremarctos orantus'' is the only species of bear to live in South America. They like to build nests that they use to sleep and eat in, in trees of high elevation in humid tropical
rain forests
Rainforests are forests characterized by a closed and continuous tree canopy, moisture-dependent vegetation, the presence of epiphytes and lianas and the absence of wildfire. Rainforests can be generally classified as tropical rainforests o ...
. They are able to live in other types of biomes too such as temperate grasslands,
deciduous forests
In the fields of horticulture and botany, the term deciduous () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed leaves, usually in the autumn; to the shedding of petals, after flo ...
, and more. Where they choose to live is dependent upon the type of food/resources that are available in the habitat.
Diet
The diet of ''Tremarctos'' bears is varied. They are considered
omnivore
An omnivore () is an animal that regularly consumes significant quantities of both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize t ...
s as they eat fruit, corn, plants, insects, farm animals, and more.
Species under this genus are able to use their paws to manipulate food. They can strip leaves off of trees, pick apart fruits, grasp food, etc. They do this with the help of having a radius
sesamoid
In anatomy, a sesamoid bone () is a bone embedded within a tendon or a muscle. Its name is derived from the Greek word for 'sesame seed', indicating the small size of most sesamoids. Often, these bones form in response to strain, or can be presen ...
, also referred to as a "false thumb".
Hunting and eating take up most of a ''Tremarctos'' bears activity levels. ''Tremarctos'' bears are diturnal meaning that they will hunt during either the day, evening, or night, meaning they do not hibernate. It depends on where the bear is located and what the current season is that determines when they are the most active.
Etymology
The genus name ''Tremarctos'' was created in 1855 by Alfred Gervais. While his suggestion for making ''Tremarctos'' a separate genus was rejected, after further studies comparing skeletal structures of the teeth and jaws of ''Tremarctos'' to other bear species his suggestion was later then accepted.
The word ''Tremarctos'' is derived from the Greek language and translates to "hole bear" in English. If one were to look at humerus of this type of bear, one would notice a hole in the middle of it. This is where its name comes from and why it is called the "hole bear". However, the name "hole bear" could also come from the fact that the tan facial markings appear on the face except around the bear's eyes, making it look like the bear has holes for eyes, giving it the '' Jukumari'' in the Andean culture.
Physical Characteristics
Size
Species under the ''Tremartcos'' genus are about average-sized bears, similar in size to the
American Black Bear
The American black bear (''Ursus americanus''), or simply black bear, is a species of medium-sized bear which is Endemism, endemic to North America. It is the continent's smallest and most widely distributed bear species. It is an omnivore, with ...
. They can weigh anywhere from 150 to 400 lbs. The ''Tremarctos Floridanus'' however, was bigger than ''Tremarctos Orantus''. Both species are
sexually dimorphic
Sexual dimorphism is the condition where sexes of the same species exhibit different Morphology (biology), morphological characteristics, including characteristics not directly involved in reproduction. The condition occurs in most dioecy, di ...
, meaning the males are most times larger than the females in size. This also results in the males having protein blood levels higher than the females' levels. The forelimbs of ''Tremarctos'' bears are longer than their hindlimbs.
Morphology
They have long curved claws and have
plantigrade
151px, Portion of a human skeleton, showing plantigrade habit
In terrestrial animals, plantigrade locomotion means walking with the toes and metatarsals flat on the ground. It is one of three forms of locomotion adopted by terrestrial mammals. ...
feet. As for their fur, they are usually black with a tannish marking that extends from their chest to around their face. While ''Tremarctos Floridanuss exact appearance is unknown, they presumably resembled the ''Tremarctos Ornatus.'' Although they have large, deep skulls, they are the smallest in length among the bear species.
Dentation
The species under the ''Tremarctos'' genus have short
mandible
In jawed vertebrates, the mandible (from the Latin ''mandibula'', 'for chewing'), lower jaw, or jawbone is a bone that makes up the lowerand typically more mobilecomponent of the mouth (the upper jaw being known as the maxilla).
The jawbone i ...
s as well as short crania. Even though they are omnivores, the evidence of having short mandibles and crania indicates they feed mostly on plants and fruits and only sometimes eat meat. Because of this they also have resilient teeth near their cheeks. They also have small canines and large
molars
The molars or molar teeth are large, flat tooth, teeth at the back of the mouth. They are more developed in mammal, mammals. They are used primarily to comminution, grind food during mastication, chewing. The name ''molar'' derives from Latin, '' ...
showing they eat meat as well. They have 42 teeth.
Breeding
Courtship occurs between male and female ''Tremarctos'' bears and this usually involves vocalizations or playful fighting. ''Tremarctos'' are polygamous meaning the male bears breed with multiple female bears. They are also polyesterous, meaning the bears have specific breeding seasons with twins being the most common litter. Cubs are usually born during seasons when fruits and vegetables are growing and becoming ripe.
The mothering bears create dens for raising their offspring. When the cubs are born, their eyes are closed and they lack teeth. The mothers will care for the cubs for about three years and after which, they separate. Male ''Tremarctos'' bears tend to live longer than females.
Threats
While the ''Tremarctos'' bear is higher up on the food chain, it still has a couple of predators and other things that threaten them. With ''Tremarctos floridanus'' extinct, ''Tremarctos ornatus'' is the only living species of this genus, their population is slowly declining and they are considered vulnerable on the Threatened Species List. One of the biggest reasons for their decline is due to humans poaching and causing their habitat loss. In some locations they encounter predators such as
jaguar
The jaguar (''Panthera onca'') is a large felidae, cat species and the only extant taxon, living member of the genus ''Panthera'' that is native to the Americas. With a body length of up to and a weight of up to , it is the biggest cat spe ...
s and
cougar
The cougar (''Puma concolor'') (, ''Help:Pronunciation respelling key, KOO-gər''), also called puma, mountain lion, catamount and panther is a large small cat native to the Americas. It inhabits North America, North, Central America, Cent ...
s. They are also susceptible to parasites such as
tick
Ticks are parasitic arachnids of the order Ixodida. They are part of the mite superorder Parasitiformes. Adult ticks are approximately 3 to 5 mm in length depending on age, sex, and species, but can become larger when engorged. Ticks a ...
s and
nematode
The nematodes ( or ; ; ), roundworms or eelworms constitute the phylum Nematoda. Species in the phylum inhabit a broad range of environments. Most species are free-living, feeding on microorganisms, but many are parasitic. Parasitic worms (h ...
s as well as diseases such as
alopecia
Hair loss, also known as alopecia or baldness, refers to a loss of hair from part of the head or body. Typically at least the head is involved. The severity of hair loss can vary from a small area to the entire body. Inflammation or scarring ...