Post by DinosaurMichael on Jan 19, 2012 19:41:54 GMT -5
Jefferson's Ground Sloth - Megalonyx jeffersonii
Megalonyx jeffersonii, or Jefferson's ground sloth, is an extinct species of giant ground sloth that lived from the Illinoian Stage during the Middle Pleistocene (150,000 years BP) through to the Rancholabrean of the Late Pleistocene (10,000 BC). Its closest living relatives are the two-toed tree sloths of the genus Choloepus. This species ranged widely in North America. It belongs to the genus Megalonyx, a name proposed by Thomas Jefferson, future president of the United States, in 1797. (Jefferson's surname was appended to the animal as the specific epithet in 1822 by the French zoologist Anselme Gaëtan Desmarest.). M. jeffersonii was a large, heavily built animal about 8 to 10 feet (2.5–3 m) long. Its maximum weight may have been as much as 800 pounds (360 kg). This is medium-sized among the giant ground sloths. Like other ground sloths it had a blunt snout, massive jaw, and large peg-like teeth. The hind limbs were plantigrade (flat-footed) and this, along with its stout tail, allowed it to rear up into a semi-erect position to feed on tree leaves. The forelimbs had three highly developed claws that were probably used to strip leaves and tear off branches. M. jeffersonii was apparently the most wide ranging giant ground sloth. Fossils are known from many Pleistocene sites in the United States, including most of the states east of the Rocky Mountains as well as along the west coast. It was the only ground sloth to range as far north as the present-day Yukon and Alaska. In the fall of 2010, the first specimen ever found in Colorado was discovered at the Ziegler Reservoir site near Snowmass Village (In the Rocky Mountains at an elevation of 8,874 feet).
Gigantopithecus - Gigantopithecus blacki
Gigantopithecus (from the Ancient Greek γίγας gigas "giant", and πίθηκος pithekos "ape") is an extinct genus of ape that existed from roughly one million years to as recently as three hundred thousand years ago, in what is now China, India, and Vietnam, placing Gigantopithecus in the same time frame and geographical location as several hominin species. The fossil record suggests that the Gigantopithecus blacki species were the largest apes that ever lived, standing up to 3 metres (9.8 ft), and weighing up to 540 kilograms (1,200 lb). Gigantopithecus blacki (Greek and Latin for "Black's Giant Ape") is an extinct species of ape. The only known fossils of G. blacki are a few teeth and mandibles found in cave sites in Southeast Asia. As the name suggests, these are appreciably larger than those of living gorillas, but the exact size and structure of the rest of the body can only be estimated in the absence of additional findings. Dating methods have shown that G. blacki existed for about a million years, going extinct about 100,000 years ago after having been contemporary with (anatomically) modern humans (Homo sapiens) for tens of thousands of years, and co-existing with H. erectus before the appearance of H. sapiens. Based on the fossil evidence, it is believed that adult male Gigantopithecus blacki stood about 3 m (9.8 ft) tall and weighed as much as 540 kg (1,200 lb), making the species two to three times heavier than modern gorillas and nearly five times heavier than the orangutan, its closest living relative. Large males may have had an armspan of over 12 feet (3.6 m). The species was highly sexually dimorphic, with adult females roughly half the weight of males. Due to wide interspecies differences in the relationship between tooth and body size, some argue that it is more likely that Gigantopithecus was much smaller, at roughly 1.8 m (5.9 ft). The species lived in Asia and probably inhabited bamboo forests, since its fossils are often found alongside those of extinct ancestors of the panda. Most evidence points to Gigantopithecus being a plant-eater. Its appearance is not known, because of the fragmentary nature of its fossil remains. It is possible that it resembled modern gorillas, because of its supposedly similar lifestyle. Some scientists, however, think that it probably looked more like its closest modern relative, the orangutan. Being so large, it is possible that Gigantopithecus had few or no enemies when fully grown. However, younger, weak or injured individuals may have been vulnerable to predation by tigers, pythons, crocodiles, Dinofelis, hyenas, bears, and Homo erectus. In the past, it had been thought that G. blacki was an ancestor of humans, on the basis of molar evidence; this is now regarded a result of convergent evolution. G. blacki is now placed in the subfamily Ponginae along with the orangutan.
Megalonyx jeffersonii, or Jefferson's ground sloth, is an extinct species of giant ground sloth that lived from the Illinoian Stage during the Middle Pleistocene (150,000 years BP) through to the Rancholabrean of the Late Pleistocene (10,000 BC). Its closest living relatives are the two-toed tree sloths of the genus Choloepus. This species ranged widely in North America. It belongs to the genus Megalonyx, a name proposed by Thomas Jefferson, future president of the United States, in 1797. (Jefferson's surname was appended to the animal as the specific epithet in 1822 by the French zoologist Anselme Gaëtan Desmarest.). M. jeffersonii was a large, heavily built animal about 8 to 10 feet (2.5–3 m) long. Its maximum weight may have been as much as 800 pounds (360 kg). This is medium-sized among the giant ground sloths. Like other ground sloths it had a blunt snout, massive jaw, and large peg-like teeth. The hind limbs were plantigrade (flat-footed) and this, along with its stout tail, allowed it to rear up into a semi-erect position to feed on tree leaves. The forelimbs had three highly developed claws that were probably used to strip leaves and tear off branches. M. jeffersonii was apparently the most wide ranging giant ground sloth. Fossils are known from many Pleistocene sites in the United States, including most of the states east of the Rocky Mountains as well as along the west coast. It was the only ground sloth to range as far north as the present-day Yukon and Alaska. In the fall of 2010, the first specimen ever found in Colorado was discovered at the Ziegler Reservoir site near Snowmass Village (In the Rocky Mountains at an elevation of 8,874 feet).
Gigantopithecus - Gigantopithecus blacki
Gigantopithecus (from the Ancient Greek γίγας gigas "giant", and πίθηκος pithekos "ape") is an extinct genus of ape that existed from roughly one million years to as recently as three hundred thousand years ago, in what is now China, India, and Vietnam, placing Gigantopithecus in the same time frame and geographical location as several hominin species. The fossil record suggests that the Gigantopithecus blacki species were the largest apes that ever lived, standing up to 3 metres (9.8 ft), and weighing up to 540 kilograms (1,200 lb). Gigantopithecus blacki (Greek and Latin for "Black's Giant Ape") is an extinct species of ape. The only known fossils of G. blacki are a few teeth and mandibles found in cave sites in Southeast Asia. As the name suggests, these are appreciably larger than those of living gorillas, but the exact size and structure of the rest of the body can only be estimated in the absence of additional findings. Dating methods have shown that G. blacki existed for about a million years, going extinct about 100,000 years ago after having been contemporary with (anatomically) modern humans (Homo sapiens) for tens of thousands of years, and co-existing with H. erectus before the appearance of H. sapiens. Based on the fossil evidence, it is believed that adult male Gigantopithecus blacki stood about 3 m (9.8 ft) tall and weighed as much as 540 kg (1,200 lb), making the species two to three times heavier than modern gorillas and nearly five times heavier than the orangutan, its closest living relative. Large males may have had an armspan of over 12 feet (3.6 m). The species was highly sexually dimorphic, with adult females roughly half the weight of males. Due to wide interspecies differences in the relationship between tooth and body size, some argue that it is more likely that Gigantopithecus was much smaller, at roughly 1.8 m (5.9 ft). The species lived in Asia and probably inhabited bamboo forests, since its fossils are often found alongside those of extinct ancestors of the panda. Most evidence points to Gigantopithecus being a plant-eater. Its appearance is not known, because of the fragmentary nature of its fossil remains. It is possible that it resembled modern gorillas, because of its supposedly similar lifestyle. Some scientists, however, think that it probably looked more like its closest modern relative, the orangutan. Being so large, it is possible that Gigantopithecus had few or no enemies when fully grown. However, younger, weak or injured individuals may have been vulnerable to predation by tigers, pythons, crocodiles, Dinofelis, hyenas, bears, and Homo erectus. In the past, it had been thought that G. blacki was an ancestor of humans, on the basis of molar evidence; this is now regarded a result of convergent evolution. G. blacki is now placed in the subfamily Ponginae along with the orangutan.