Post by DinosaurMichael on Jul 26, 2012 7:07:04 GMT -5
Dire Wolf - Canis dirus
The dire wolf (Canis dirus) is an extinct carnivorous mammal of the genus Canis related to the smaller extant gray wolf. It was most common in North America and South America from the Irvingtonian stage to the Rancholabrean stage of the Pleistocene epoch, living 1.80 Ma—10,000 years ago, persisting for approximately 1.79 million years. The fossil record suggests that the genus Canis diverged from the small, foxlike Leptocyon in North America sometime in the Late Miocene epoch 9 to 10 million years (Ma) ago, along with two other genera, Urocyon, and Vulpes. Canids soon spread to Asia and Europe (8 Ma BP) and became the ancestors of modern wolves, jackals, foxes, and the Raccoon Dog. By 3–5 Ma BP, canids had spread to Africa (Early Pliocene) and South America (Late Pliocene). Their invasion of South America as part of the Great American Interchange was enabled by the formation of the Isthmus of Panama 3 Ma ago. Although it was closely related to the gray wolf and other sister species, Canis dirus is not the direct ancestor of any species known today. Unlike the gray wolf, which is of Eurasian origin, the dire wolf evolved on the North American continent, along with the coyote. The Dire Wolf co-existed with the Gray Wolf in North America for about 100,000 years. The dire wolf was one of the abundant Pleistocene megafauna—a wide variety of very large mammals that lived during the Pleistocene. Approximately 10,000 years ago the dire wolf became extinct along with most other North American megafauna.[9] During the Late Pleistocene (300,000 years ago) the gray wolf (Canis lupus) crossed into North America on the Bering Strait land bridge and competed with the dire wolf. Starting about 16,000 years ago, coinciding with the end of the last glacial period and the arrival of humans in North America, most of the large mammals upon which the dire wolf depended for prey began to die out (possibly as a result of climate and/or human-induced changes as suggested in a 2008 National Geographic Channel documentary). Slower than the other wolf species on the continent at the time, primarily the gray wolf and red wolf, it could not hunt the swifter species that remained and was forced to subsist by scavenging. By 10,000 years ago, the large mammals and the Dire Wolf were extinct. The dire wolf was larger than the gray wolf, averaging about 1.5 metres (5 ft) in length and weighing between 50 kg (110 lb) and 79 kg (174 lb). Despite superficial similarities to the Gray Wolf, there were significant differences between the two species. The legs of the dire wolf were proportionally shorter and sturdier than those of the gray wolf, and its brain case was smaller than that of a similarly sized gray wolf. The dire wolf's teeth were similar to the gray wolf's, only slightly larger, pointing to a hypercarnivorous to mesocarnivorous activity.
Spotted Hyena - Crocuta crocuta
The spotted hyena (Crocuta crocuta), also known as the laughing hyena or tiger wolf, is a species of hyena native to Sub-Saharan Africa. It is listed as Least Concern by the IUCN on account of its widespread range and large numbers estimated at 10,000 individuals. The species is however experiencing declines outside of protected areas due to habitat loss and poaching. The species may have originated in Asia, and once ranged throughout Europe for at least one million years until the end of the Late Pleistocene. The spotted hyena is the largest member of the Hyaenidae, and is further physically distinguished from other species by its vaguely bear-like build, its rounded ears, its less prominent mane, its spotted pelt, its more dual purposed dentition, its fewer nipples and the presence of a pseudo-penis in the female. It is the only mammalian species to lack an external vaginal opening. The spotted hyena is the most social of the Carnivora in that it has the largest group sizes and most complex social behaviours. Its social organisation is unlike that of any other Carnivore, bearing closer resemblance to that of cercopithecine primates (baboons and macaques) with respect to group-size, hierarchical structure, and frequency of social interaction among both kin and unrelated group-mates. However, the social system of the spotted hyena is openly competitive rather than cooperative, with access to kills, mating opportunities and the time of dispersal for males depending on the ability to dominate other clan-members. Females provide only for their own cubs rather than assist each other, and males display no paternal care. Spotted hyena society is matriarchal; females are larger than males, and dominate them. The spotted hyena is a highly successful animal, being the most common large carnivore in Africa. Its success is due in part to its adaptability and opportunism; it is both an efficient hunter and a scavenger, with the capacity to eat and digest skin, bone and other animal waste. In functional terms, the spotted hyena makes the most efficient use of animal matter of all African carnivores. The spotted hyena displays greater plasticity in its hunting and foraging behaviour than other African carnivores; it hunts alone, in small parties of 2-5 individuals or in large groups. During a hunt, spotted hyenas often run through ungulate herds in order to select an individual to attack. Once selected, their prey is chased over long distance, often several kilmoetres, at speeds of up to 60 km/h. The spotted hyena is the largest extant member of the Hyaenidae. Adults measure 95.0—165.8 cm in body length, and have a shoulder height of 70.0-91.5 cm. Adult male spotted hyenas in the Serengeti weigh 40.5—55.0 kg (89—121 lb), while females weigh 44.5—63.9 kg (98—141 lb). Spotted hyenas in Zambia tend to be heavier, with males weighing on average 67.6 kg (149 lb), and females 69.2 kg (153 lb). Exceptionally large weights of 81.7 kg (180 lb) and 86 kg (190 lb) are known.
The dire wolf (Canis dirus) is an extinct carnivorous mammal of the genus Canis related to the smaller extant gray wolf. It was most common in North America and South America from the Irvingtonian stage to the Rancholabrean stage of the Pleistocene epoch, living 1.80 Ma—10,000 years ago, persisting for approximately 1.79 million years. The fossil record suggests that the genus Canis diverged from the small, foxlike Leptocyon in North America sometime in the Late Miocene epoch 9 to 10 million years (Ma) ago, along with two other genera, Urocyon, and Vulpes. Canids soon spread to Asia and Europe (8 Ma BP) and became the ancestors of modern wolves, jackals, foxes, and the Raccoon Dog. By 3–5 Ma BP, canids had spread to Africa (Early Pliocene) and South America (Late Pliocene). Their invasion of South America as part of the Great American Interchange was enabled by the formation of the Isthmus of Panama 3 Ma ago. Although it was closely related to the gray wolf and other sister species, Canis dirus is not the direct ancestor of any species known today. Unlike the gray wolf, which is of Eurasian origin, the dire wolf evolved on the North American continent, along with the coyote. The Dire Wolf co-existed with the Gray Wolf in North America for about 100,000 years. The dire wolf was one of the abundant Pleistocene megafauna—a wide variety of very large mammals that lived during the Pleistocene. Approximately 10,000 years ago the dire wolf became extinct along with most other North American megafauna.[9] During the Late Pleistocene (300,000 years ago) the gray wolf (Canis lupus) crossed into North America on the Bering Strait land bridge and competed with the dire wolf. Starting about 16,000 years ago, coinciding with the end of the last glacial period and the arrival of humans in North America, most of the large mammals upon which the dire wolf depended for prey began to die out (possibly as a result of climate and/or human-induced changes as suggested in a 2008 National Geographic Channel documentary). Slower than the other wolf species on the continent at the time, primarily the gray wolf and red wolf, it could not hunt the swifter species that remained and was forced to subsist by scavenging. By 10,000 years ago, the large mammals and the Dire Wolf were extinct. The dire wolf was larger than the gray wolf, averaging about 1.5 metres (5 ft) in length and weighing between 50 kg (110 lb) and 79 kg (174 lb). Despite superficial similarities to the Gray Wolf, there were significant differences between the two species. The legs of the dire wolf were proportionally shorter and sturdier than those of the gray wolf, and its brain case was smaller than that of a similarly sized gray wolf. The dire wolf's teeth were similar to the gray wolf's, only slightly larger, pointing to a hypercarnivorous to mesocarnivorous activity.
Spotted Hyena - Crocuta crocuta
The spotted hyena (Crocuta crocuta), also known as the laughing hyena or tiger wolf, is a species of hyena native to Sub-Saharan Africa. It is listed as Least Concern by the IUCN on account of its widespread range and large numbers estimated at 10,000 individuals. The species is however experiencing declines outside of protected areas due to habitat loss and poaching. The species may have originated in Asia, and once ranged throughout Europe for at least one million years until the end of the Late Pleistocene. The spotted hyena is the largest member of the Hyaenidae, and is further physically distinguished from other species by its vaguely bear-like build, its rounded ears, its less prominent mane, its spotted pelt, its more dual purposed dentition, its fewer nipples and the presence of a pseudo-penis in the female. It is the only mammalian species to lack an external vaginal opening. The spotted hyena is the most social of the Carnivora in that it has the largest group sizes and most complex social behaviours. Its social organisation is unlike that of any other Carnivore, bearing closer resemblance to that of cercopithecine primates (baboons and macaques) with respect to group-size, hierarchical structure, and frequency of social interaction among both kin and unrelated group-mates. However, the social system of the spotted hyena is openly competitive rather than cooperative, with access to kills, mating opportunities and the time of dispersal for males depending on the ability to dominate other clan-members. Females provide only for their own cubs rather than assist each other, and males display no paternal care. Spotted hyena society is matriarchal; females are larger than males, and dominate them. The spotted hyena is a highly successful animal, being the most common large carnivore in Africa. Its success is due in part to its adaptability and opportunism; it is both an efficient hunter and a scavenger, with the capacity to eat and digest skin, bone and other animal waste. In functional terms, the spotted hyena makes the most efficient use of animal matter of all African carnivores. The spotted hyena displays greater plasticity in its hunting and foraging behaviour than other African carnivores; it hunts alone, in small parties of 2-5 individuals or in large groups. During a hunt, spotted hyenas often run through ungulate herds in order to select an individual to attack. Once selected, their prey is chased over long distance, often several kilmoetres, at speeds of up to 60 km/h. The spotted hyena is the largest extant member of the Hyaenidae. Adults measure 95.0—165.8 cm in body length, and have a shoulder height of 70.0-91.5 cm. Adult male spotted hyenas in the Serengeti weigh 40.5—55.0 kg (89—121 lb), while females weigh 44.5—63.9 kg (98—141 lb). Spotted hyenas in Zambia tend to be heavier, with males weighing on average 67.6 kg (149 lb), and females 69.2 kg (153 lb). Exceptionally large weights of 81.7 kg (180 lb) and 86 kg (190 lb) are known.
