Post by DinosaurMichael on May 30, 2012 9:16:53 GMT -5
South American Giant Short-faced Bear - Arctotherium angustidens
Arctotherium is an extinct genus of South American short-faced bears within Ursidae of the late Pliocene through the end of the Pleistocene. Their ancestors migrated from North America to South America during the Great American Interchange, following the formation of the Isthmus of Panama. They were endemic to South America, living from ~2.0–0.01 Ma, existing for approximately 1.99 million years. Their closest relatives were the North American short-faced bears of genus Arctodus (A. pristinus and A. simus). The closest living relative would be the spectacled bear (Tremarctos ornatus). Arctotherium was named by Hermann Burmeister in 1879. It was assigned to Tremarctinae by Krause et al. 2008. A humerus of A. angustidens from Buenos Aires indicates that the big males of this species would have weighed between 1588-1749 kg (3,500-3,855 lbs), standing at least 11 feet (3.4 meters) tall, making it the largest bear and the largest carnivorous land mammal yet known. In contrast to their North American cousins, South American short-faced bears showed a trend of declining size and carnivory over time. This has been attributed to increased competition from other, later-arriving or evolving carnivorans, like jaguars, lions or Smilodon populator, following the early dispersal of short-faced bears to South America.
Harlan's Ground Sloth - Paramylodon harlani
Harlan's Ground Sloth is an extinct genus of ground sloth of the family Mylodontidae endemic to North America during the Pliocene through Pleistocene epochs, living from around ~4.9 Mya—11,000 years ago (approximately 4.889 million years). Harlan's Ground Sloth measured about 3 m (9.8 ft) in height and weighed 3,500 lbs. It is known from North America deposits, including in Mexico and the United States and as far south as Guatemala, and often mistaken as Glossotherium. Currently there is just one recognized species, P. harlani, which is commonly referred to as Harlan's ground sloth in honor of American paleontologist Dr. Richard Harlan who first discovered and described a lower jaw in 1835. The Harlan's Ground Sloth exhibits the interesting characteristic of having had dermal ossicles, small bones embedded in the skin, presumably adding a degree of protection to the animal. This characteristic is also shared by the South American Mylodon.
Arctotherium is an extinct genus of South American short-faced bears within Ursidae of the late Pliocene through the end of the Pleistocene. Their ancestors migrated from North America to South America during the Great American Interchange, following the formation of the Isthmus of Panama. They were endemic to South America, living from ~2.0–0.01 Ma, existing for approximately 1.99 million years. Their closest relatives were the North American short-faced bears of genus Arctodus (A. pristinus and A. simus). The closest living relative would be the spectacled bear (Tremarctos ornatus). Arctotherium was named by Hermann Burmeister in 1879. It was assigned to Tremarctinae by Krause et al. 2008. A humerus of A. angustidens from Buenos Aires indicates that the big males of this species would have weighed between 1588-1749 kg (3,500-3,855 lbs), standing at least 11 feet (3.4 meters) tall, making it the largest bear and the largest carnivorous land mammal yet known. In contrast to their North American cousins, South American short-faced bears showed a trend of declining size and carnivory over time. This has been attributed to increased competition from other, later-arriving or evolving carnivorans, like jaguars, lions or Smilodon populator, following the early dispersal of short-faced bears to South America.
Harlan's Ground Sloth - Paramylodon harlani
Harlan's Ground Sloth is an extinct genus of ground sloth of the family Mylodontidae endemic to North America during the Pliocene through Pleistocene epochs, living from around ~4.9 Mya—11,000 years ago (approximately 4.889 million years). Harlan's Ground Sloth measured about 3 m (9.8 ft) in height and weighed 3,500 lbs. It is known from North America deposits, including in Mexico and the United States and as far south as Guatemala, and often mistaken as Glossotherium. Currently there is just one recognized species, P. harlani, which is commonly referred to as Harlan's ground sloth in honor of American paleontologist Dr. Richard Harlan who first discovered and described a lower jaw in 1835. The Harlan's Ground Sloth exhibits the interesting characteristic of having had dermal ossicles, small bones embedded in the skin, presumably adding a degree of protection to the animal. This characteristic is also shared by the South American Mylodon.
