Post by DinosaurMichael on Aug 4, 2012 4:56:26 GMT -5
Muskox - Ovibos moschatus
The muskox (Ovibos moschatus, musk ox) is an Arctic mammal of the family Bovidae, noted for its thick coat and for the strong odor emitted by males, from which its name derives. This musky odor is used to attract females during mating season. Muskoxen primarily live in Arctic North America and Greenland, with small introduced populations in Sweden, Siberia and Norway. The muskox, or its ancestor, is believed to have migrated to North America between 200,000 and 90,000 years ago, during the Pleistocene period, when it was a contemporary of the woolly mammoth. It is thought that the muskox was able to survive the last ice age (Wisconsin glaciation) by finding ice-free areas away from prehistoric peoples. The muskox gradually moved across North America and arrived in Greenland during the late Holocene. As members of the subfamily Caprinae of the family Bovidae, muskoxen are more closely related to sheep and goats than to oxen, but are in their own genus, Ovibos (Latin: "sheep-ox"). The muskox is one of the two largest extant members of this subfamily, besides the similarly-sized takin. Both sexes have long curved horns. Muskoxen stand 1.1 to 1.5 m (4 to 5 ft) high at the shoulder, with females measuring 135 to 200 cm (4.4 to 6.6 ft) in length, and the larger males 200 to 250 cm (6.6 to 8.2 ft). The small tail, often concealed under a layer of fur, measures only 10 cm (3.9 in) long. Adults, on average, weigh 285 kg (600 lb) and range from 180 to 410 kg (400 to 900 lb). Their life expectancy is 12–20 years. The thick coat and large head often suggests a larger animal than the muskox truly is and, the bison, to which the muskox is regularly compared, can weigh up to twice as much. However, heavy zoo-kept specimens have weighed up to 650 kilograms (1,400 lb). Their coat, a mix of black, gray, and brown, includes long guard hairs that almost reach the ground.
Postosuchus - Postosuchus kirkpatricki
Postosuchus, meaning "crocodile from Post (Garza, Texas)", was a basal archosaur that lived in what is now North America during the middle through to the late Triassic period (228-202 million years ago). It was a rauisuchian, a close relative of crocodiles, as a member of the clade Pseudosuchia (or Crurotarsi) which, along with the lineage that led to dinosaurs and Birds, forms Archosauria. Its name refers to Post Quarry, a place in Texas where many fossils of this genus were found. It was one of the apex predators of its area during the Triassic, larger than the small dinosaur predators of its time (such as Coelophysis). It was a hunter which probably preyed on dicynodonts and many other creatures smaller than itself. Postosuchus was a quadrupedal reptile with a wide skull and a long tail. This carnivore attacked with its large curved claws. It was about 4–5 meters long (12–15 feet), and was held up by columnar legs (a quite uncommon feature in reptiles). A crocodile-like snout, filled with many large-sized dagger-like teeth, was used to kill its prey. Rows of protective plates covering its back formed a defensive shield. Postosuchus was one of the largest carnivorous reptiles during the late Triassic, reaching up to 4 meters (13 ft) in length and 2 meters (6.5 ft) in height. In life the animal would weigh about 250 to 300 kilograms (550lb to 660lb). It had a massively built skull bearing dagger-like teeth. The neck was elongated, expanding to a short torso and long tail. Each one of Postosuchus's two forelimbs was slightly over half the size of the hindlimbs. This characteristic of short forelimbs can usually be seen in bipedal reptiles. Chatterjee suggested that Postosuchus could walk in an erect stance, since the short forelimbs were probably used only during slow locomotion. However, in 1995 Long and Murry stated that Postosuchus was heavily built and quadrupedal. There is debate over whether Postosuchus was bipedal or quadrupedal and scientists aren't certain, yet, about its gait. However, it has also been suggested by some palaeontologists that Postosuchus might possibly have been a facultative biped, meaning that it alternated between walking bipedally, occasionally, and quadrupedally.
The muskox (Ovibos moschatus, musk ox) is an Arctic mammal of the family Bovidae, noted for its thick coat and for the strong odor emitted by males, from which its name derives. This musky odor is used to attract females during mating season. Muskoxen primarily live in Arctic North America and Greenland, with small introduced populations in Sweden, Siberia and Norway. The muskox, or its ancestor, is believed to have migrated to North America between 200,000 and 90,000 years ago, during the Pleistocene period, when it was a contemporary of the woolly mammoth. It is thought that the muskox was able to survive the last ice age (Wisconsin glaciation) by finding ice-free areas away from prehistoric peoples. The muskox gradually moved across North America and arrived in Greenland during the late Holocene. As members of the subfamily Caprinae of the family Bovidae, muskoxen are more closely related to sheep and goats than to oxen, but are in their own genus, Ovibos (Latin: "sheep-ox"). The muskox is one of the two largest extant members of this subfamily, besides the similarly-sized takin. Both sexes have long curved horns. Muskoxen stand 1.1 to 1.5 m (4 to 5 ft) high at the shoulder, with females measuring 135 to 200 cm (4.4 to 6.6 ft) in length, and the larger males 200 to 250 cm (6.6 to 8.2 ft). The small tail, often concealed under a layer of fur, measures only 10 cm (3.9 in) long. Adults, on average, weigh 285 kg (600 lb) and range from 180 to 410 kg (400 to 900 lb). Their life expectancy is 12–20 years. The thick coat and large head often suggests a larger animal than the muskox truly is and, the bison, to which the muskox is regularly compared, can weigh up to twice as much. However, heavy zoo-kept specimens have weighed up to 650 kilograms (1,400 lb). Their coat, a mix of black, gray, and brown, includes long guard hairs that almost reach the ground.
Postosuchus - Postosuchus kirkpatricki
Postosuchus, meaning "crocodile from Post (Garza, Texas)", was a basal archosaur that lived in what is now North America during the middle through to the late Triassic period (228-202 million years ago). It was a rauisuchian, a close relative of crocodiles, as a member of the clade Pseudosuchia (or Crurotarsi) which, along with the lineage that led to dinosaurs and Birds, forms Archosauria. Its name refers to Post Quarry, a place in Texas where many fossils of this genus were found. It was one of the apex predators of its area during the Triassic, larger than the small dinosaur predators of its time (such as Coelophysis). It was a hunter which probably preyed on dicynodonts and many other creatures smaller than itself. Postosuchus was a quadrupedal reptile with a wide skull and a long tail. This carnivore attacked with its large curved claws. It was about 4–5 meters long (12–15 feet), and was held up by columnar legs (a quite uncommon feature in reptiles). A crocodile-like snout, filled with many large-sized dagger-like teeth, was used to kill its prey. Rows of protective plates covering its back formed a defensive shield. Postosuchus was one of the largest carnivorous reptiles during the late Triassic, reaching up to 4 meters (13 ft) in length and 2 meters (6.5 ft) in height. In life the animal would weigh about 250 to 300 kilograms (550lb to 660lb). It had a massively built skull bearing dagger-like teeth. The neck was elongated, expanding to a short torso and long tail. Each one of Postosuchus's two forelimbs was slightly over half the size of the hindlimbs. This characteristic of short forelimbs can usually be seen in bipedal reptiles. Chatterjee suggested that Postosuchus could walk in an erect stance, since the short forelimbs were probably used only during slow locomotion. However, in 1995 Long and Murry stated that Postosuchus was heavily built and quadrupedal. There is debate over whether Postosuchus was bipedal or quadrupedal and scientists aren't certain, yet, about its gait. However, it has also been suggested by some palaeontologists that Postosuchus might possibly have been a facultative biped, meaning that it alternated between walking bipedally, occasionally, and quadrupedally.
