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Macraucheniidae
Macraucheniidae is a family in the extinct South American ungulate order Litopterna, that resembled various camelids. The reduced nasal bones of their skulls was originally suggested to have housed a small proboscis, similar to that of the saiga antelope. However, one study suggested that they were openings for large moose-like nostrils. Conversely, prehistoric pictographs by indigenous people seems to depict animals interpreted as macraucheniids with trunks. Their hooves were similar to those of rhinoceroses today, with a simple ankle joint and three digits on each foot. Thus, they may have been capable of rapid directional change when running away from predators, such as large phorusrhacid terror birds, sparassodont metatherians, giant short-faced bears ('' Arctotherium)'' and saber-toothed cats (''Smilodon''). Macraucheniids probably lived in large herds to gain protection against these predators, as well as to facilitate finding mates for reproduction. The family Macrauc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Llullataruca
''Llullataruca'' is an extinct genus of macraucheniid litoptern. It lived during the Middle Miocene of what is now Bolivia. Etymology The genus name, ''Llullataruca,'' is derived from the Quechua words ''llulla'' meaning "false", "lie" or "deceitful", and taruca, meaning "deer", an indigenous language of the Quebrada Honda region, which refers to the presumed habits of the small-to mid-sized macraucheniids as cursorial browsers or mixed feeders, a niche filled today in many parts of the world, including southern Bolivia, by cervids. The species name, ''shockeyi'' honors of Bruce Shockey for his endless efforts to improve knowledge of Cenozoic mammals in Bolivia and his many insights that have improved other scientists understanding of the paleobiology of native South American ungulates, including macraucheniids. Description This animal is known only from incomplete remains, mainly a jaw with teeth, but from comparison with better known similar animals, such as '' Cramauche ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eocene
The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', " dawn") and (''kainós'', "new") and refers to the "dawn" of modern ('new') fauna that appeared during the epoch. The Eocene spans the time from the end of the Paleocene Epoch to the beginning of the Oligocene Epoch. The start of the Eocene is marked by a brief period in which the concentration of the carbon isotope 13C in the atmosphere was exceptionally low in comparison with the more common isotope 12C. The end is set at a major extinction event called the ''Grande Coupure'' (the "Great Break" in continuity) or the Eocene–Oligocene extinction event, which may be related to the impact of one or more large bolides in Siberia and in what is now Chesapeake Bay. As with other geologic periods, the strata that define the start and e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proboscis
A proboscis () is an elongated appendage from the head of an animal, either a vertebrate or an invertebrate. In invertebrates, the term usually refers to tubular mouthparts used for feeding and sucking. In vertebrates, a proboscis is an elongated nose or snout. Etymology First attested in English in 1609 from Latin , the latinisation of the Ancient Greek (), which comes from () 'forth, forward, before' + (), 'to feed, to nourish'. The plural as derived from the Greek is , but in English the plural form ''proboscises'' occurs frequently. Invertebrates The most common usage is to refer to the tubular feeding and sucking organ of certain invertebrates such as insects (e.g., moths, butterflies, and mosquitoes), worms (including Acanthocephala, proboscis worms) and gastropod molluscs. Acanthocephala The Acanthocephala or thorny-headed worms, or spiny-headed worms are characterized by the presence of an eversible proboscis, armed with spines, which it uses to pierce an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arctotherium
''Arctotherium'' ("''bear beast''") is an extinct genus of the Pleistocene short-faced bears endemic to Central and South America. ''Arctotherium'' migrated from North America to South America during the Great American Interchange, following the formation of the Isthmus of Panama during the late Pliocene. The genus consists of one early giant form, ''A. angustidens'', and several succeeding smaller species, which were within the size range of modern bears. ''Arctotherium'' was adapted to open and mixed habitat. They are genetically closer to the spectacled bear (''Tremarctos ornatus''), than to ''Arctodus'' of North America, implying the two extinct forms evolved large size in a convergent manner, perhaps to facilitate dominating other carnivores in the competition for the biggest carcasses. Evolution Tremarctinae ''Arctotherium'' is part of the Tremarctinae subfamily of bears, otherwise known as the short faced bears, which also includes ''Arctodus'' (North American shor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bears
Bears are carnivoran mammals of the 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 throughout the Northern Hemisphere and partially in the Southern Hemisphere. Bears are found on the continents of North America, South America, Europe, and Asia. Common characteristics of modern bears include large bodies with stocky legs, long snouts, small rounded ears, shaggy hair, plantigrade paws with five nonretractile claws, and short tails. While the polar bear is mostly carnivorous, and the giant panda feeds almost entirely on bamboo, the remaining six species are omnivorous with varied diets. With the exception of courting individuals and mothers with their young, bears are typically solitary animals. They may be diurnal or nocturnal and have an excellent sense of smell. Despite their heavy build and awkward gait, they are adept runners, clim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 (''Tremarctos floridanus''), the North American giant short-faced bears '' Arctodus'' (''A. pristinus'' and ''A. simus''), the South American giant short-faced bear '' Arctotherium'' (including ''A. angustidens'', ''A. vetustum'', ''A. bonariense'', ''A. wingei'', and ''A. tarijense)'' as well as '' Plionarctos'' ''(P. edensis and P. harroldorum),'' which is thought to be ancestral to the other three genera. Of these, the giant short-faced bears (''Arctodus simus'' and '' Arctotherium angustidens'') may have been the largest ever carnivorans in the Americas. The group is thought to have originated in eastern North America, and then invaded South America as part of the Great American Interchange. Most short-faced bears became extinct at t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metatherians
Metatheria is a mammalian clade that includes all mammals more closely related to marsupials than to placentals. First proposed by Thomas Henry Huxley in 1880, it is a more inclusive group than the marsupials; it contains all marsupials as well as many extinct non-marsupial relatives. There are three extant subclasses of mammals, one being metatherians: # monotremes: egg laying mammals like the platypus and the echidna, #metatheria: marsupials, which includes three American orders ( Didelphimorphia, Paucituberculata and Microbiotheria) and four Australasian orders ( Notoryctemorphia, Dasyuromorphia, Peramelemorphia and Diprotodontia), and the #eutherians: placental mammals, consisting of four superorders divided into 21 orders. Metatherians belong to a subgroup of the northern tribosphenic mammal clade or Boreosphenida. They differ from all other mammals in certain morphologies like their dental formula, which includes about five upper and four lower incisors, a cani ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sparassodonta
Sparassodonta (from Greek to tear, rend; and , gen. , ' tooth) is an extinct order of carnivorous metatherian mammals native to South America, related to modern marsupials. They were once considered to be true marsupials, but are now thought to be a separate side branch that split before the last common ancestor of all modern marsupials. A number of these mammalian predators closely resemble placental predators that evolved separately on other continents, and are cited frequently as examples of convergent evolution. They were first described by Florentino Ameghino, from fossils found in the Santa Cruz beds of Patagonia. Sparassodonts were present throughout South America's long period of "splendid isolation" during the Cenozoic; during this time, they shared the niches for large warm-blooded predators with the flightless terror birds. Previously, it was thought that these mammals died out in the face of competition from "more competitive" placental carnivorans during the Pli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phorusrhacidae
Phorusrhacids, colloquially known as terror birds, are an extinct clade of large carnivorous flightless birds that were one of the largest species of apex predators in South America during the Cenozoic era; their conventionally accepted temporal range covers from 62 to 0.1 million years ( Ma) ago. They ranged in height from . Their closest modern-day relatives are believed to be the seriemas. '' Titanis walleri'', one of the larger species, is known from Texas and Florida in North America. This makes the phorusrhacids the only known large South American predator to migrate north in the Great American Interchange that followed the formation of the Isthmus of Panama land bridge (the main pulse of the interchange began about 2.6 Ma ago; ''Titanis'' at 5 Ma was an early northward migrant). It was once believed that ''T. walleri'' became extinct in North America around the time of the arrival of humans, but subsequent datings of ''Titanis'' fossils provided no evidence for their s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Predator
Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill the host) and parasitoidism (which always does, eventually). It is distinct from scavenging on dead prey, though many predators also scavenge; it overlaps with herbivory, as seed predators and destructive frugivores are predators. Predators may actively search for or pursue prey or wait for it, often concealed. When prey is detected, the predator assesses whether to attack it. This may involve ambush or pursuit predation, sometimes after stalking the prey. If the attack is successful, the predator kills the prey, removes any inedible parts like the shell or spines, and eats it. Predators are adapted and often highly specialized for hunting, with acute senses such as vision, hearing, or smell. Many predatory animals, both vertebra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhinoceros
A rhinoceros (; ; ), commonly abbreviated to rhino, is a member of any of the five extant taxon, extant species (or numerous extinct species) of odd-toed ungulates in the family (biology), family Rhinocerotidae. (It can also refer to a member of any of the extinct species of the superfamily Rhinocerotoidea.) Two of the extant species are native to Africa, and three to South Asia, South and Southeast Asia. Rhinoceroses are some of the largest remaining megafauna: all weigh at least one tonne in adulthood. They have a herbivore, herbivorous diet, small brains (400–600 g) for mammals of their size, one or two horns, and a thick (1.5–5 cm), protective skin formed from layers of collagen positioned in a crystal structure, lattice structure. They generally eat leafy material, although their ability to ferment food in their colon (anatomy), hindgut allows them to subsist on more fibrous plant matter when necessary. Unlike other perissodactyls, the two African species of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hoof
The hoof (plural: hooves) is the tip of a toe of an ungulate mammal, which is covered and strengthened with a thick and horny keratin covering. Artiodactyls are even-toed ungulates, species whose feet have an even number of digits, yet the ruminants with two digits, are the most numerous, e.g. giraffe, deer, bison, cattle, goat, and sheep. The feet of perissodactyl mammals have an odd number of toes, e.g. the horse, the rhinoceros, and the tapir. Hooves are limb structures restricted to placental mammals, which have long pregnancies; however, the marsupial '' Chaeropus'' had hooves. Description The hoof surrounds the distal end of the second phalanx, the distal phalanx, and the navicular bone. The hoof consists of the hoof wall, the bars of the hoof, the sole and frog and soft tissue shock absorption structures. The weight of the animal is normally borne by both the sole and the edge of the hoof wall. Hooves perform many functions, including supporting the weight of the a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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