Post by DinosaurMichael on Feb 17, 2012 10:05:46 GMT -5
Western Gorilla - Gorilla gorilla
The western gorilla (Gorilla gorilla) is a great ape and the most populous species of the genus Gorilla. Nearly all of the individuals of this taxon belong to the western lowland gorilla subspecies (G. g. gorilla) whose population is approximately 95,000 individuals. There are fewer than 300 of the only other western gorilla subspecies, the Cross River gorilla (G. g. diehli). The western gorilla is slightly smaller, lighter, more slender and clearer dyed than its eastern cousin. The western lowland gorilla can be brown or greyish with a yellowish forehead. It also has an overhanging tip on its nose, which the eastern gorilla does not have. Males measure 160–170 cm and weigh 140–160 kg. Females measure 120–140 cm and weigh 60–80 kg. The western gorilla is the smaller species of the gorilla. The Cross River gorilla differs from the western lowland gorilla in both skull and tooth dimensions. It is also about 10–15 cm taller and 20–35 kg heavier, but still smaller and lighter than the mountain gorilla and the eastern lowland gorilla, latter the largest subspecies of the gorilla and the largest living primate. Western gorillas live in groups that vary in size between 2 and 20 individuals, composed of at least one male, several females and their offspring. A dominant male silverback heads the group, with younger males usually leaving the group when they reach maturity. Females transfer to another group before breeding, which begins at eight to nine years old; they care for their young infant for the first three to four years of its life. There is therefore a long interval between births, which partly explains the slow population growth rates that make the western gorilla so vulnerable to poaching. Due to the long gestation time, long period of parental care, and infant mortality, a female gorilla will only give birth to an offspring that survives to maturity every six to eight years. Gorillas are long-lived and may survive for as long as 40 years in the wild. Fruit forms a large part of the western gorilla's diet and they will travel further each day in search of fruiting trees than their eastern relatives. The distance that gorillas travel in the forest each day while they are searching for fruit trees varies between one and four kilometres. A group's home range may be as large as 30 square kilometres but is not actively defended. Wild western gorillas are known to use tools.
Deinonychus - Deinonychus antirrhopus
Deinonychus (/daɪˈnɒnɨkəs/ dy-NON-i-kəs; Greek: δεινός, 'terrible' and ὄνυξ, genitive ὄνυχος 'claw') was a genus of carnivorous dromaeosaurid dinosaur. There is one described species, Deinonychus antirrhopus. This 3.4 meter (11 ft) long dinosaur lived during the early Cretaceous Period, about 115–108 million years ago (from the mid-Aptian to early Albian stages). Fossils have been recovered from the U.S. states of Montana, Wyoming, and Oklahoma, in rocks of the Cloverly Formation and Antlers Formation, though teeth that may belong to Deinonychus have been found much farther east in Maryland. Paleontologist John Ostrom's study of Deinonychus in the late 1960s revolutionized the way scientists thought about dinosaurs, leading to the "dinosaur renaissance" and igniting the debate on whether dinosaurs were warm-blooded or cold blooded. Before this, the popular conception of dinosaurs had been one of plodding, reptilian giants. Ostrom noted the small body, sleek, horizontal posture, ratite-like spine, and especially the enlarged raptorial claws on the feet, which suggested an active, agile predator. "Terrible claw" refers to the unusually large, sickle-shaped talon on the second toe of each hind foot. The fossil YPM 5205 preserves a large, strongly curved ungual. In life, archosaurs have a horny sheath over this bone which extends the length. Ostrom looked at crocodile and bird claws and reconstructed the claw for YPM 5205 as over 120 millimetres (4.7 in) long. The species name antirrhopus means “counter balance”, which refers to Ostrom's idea about the function of the tail. As in other dromaeosaurids, the tail vertebrae have a series of ossified tendons and super-elongated bone processes. These features seemed to make the tail into a stiff counterbalance, but a fossil of the very closely related Velociraptor mongoliensis (IGM 100/986) has an articulated tail skeleton that is curved laterally in a long S–shape. This suggests that, in life, the tail could bend to the sides with a high degree of flexibility. Based on the largest known specimens, Deinonychus could reach at least 3.4 metres (11 ft 2 in) in length, with a skull length of 410 mm (16.1 in), a hip height of 0.87 metres (2 ft 10 in), and an estimated weight of 73 kilograms (160 lb). Its skull was equipped with powerful jaws lined with around seventy curved, blade-like teeth. Studies of the skull have progressed a great deal over the decades. Ostrom reconstructed the partial, imperfectly preserved, skulls that he had as triangular, broad, and fairly similar to Allosaurus. Additional Deinonychus skull material and closely related species found with good three-dimensional preservation show that the palate was more vaulted than Ostrom thought, making the snout far narrower, while the jugals flared broadly, giving greater stereoscopic vision. The skull of Deinonychus was different from that of Velociraptor, however, in that it had a more robust skull roof like that of Dromaeosaurus, and did not have the depressed nasals of Velociraptor. Both the skull and the lower jaw had fenestrae (skull openings) which reduced the weight of the skull. In Deinonychus, the antorbital fenestra, a skull opening between the eye and nostril, was particularly large. Deinonychus possessed large hands (manus) with three claws on each forelimb. The first digit was shortest and the second was longest. Each hind foot bore a sickle-shaped claw on the second digit, which was probably used during predation.
The western gorilla (Gorilla gorilla) is a great ape and the most populous species of the genus Gorilla. Nearly all of the individuals of this taxon belong to the western lowland gorilla subspecies (G. g. gorilla) whose population is approximately 95,000 individuals. There are fewer than 300 of the only other western gorilla subspecies, the Cross River gorilla (G. g. diehli). The western gorilla is slightly smaller, lighter, more slender and clearer dyed than its eastern cousin. The western lowland gorilla can be brown or greyish with a yellowish forehead. It also has an overhanging tip on its nose, which the eastern gorilla does not have. Males measure 160–170 cm and weigh 140–160 kg. Females measure 120–140 cm and weigh 60–80 kg. The western gorilla is the smaller species of the gorilla. The Cross River gorilla differs from the western lowland gorilla in both skull and tooth dimensions. It is also about 10–15 cm taller and 20–35 kg heavier, but still smaller and lighter than the mountain gorilla and the eastern lowland gorilla, latter the largest subspecies of the gorilla and the largest living primate. Western gorillas live in groups that vary in size between 2 and 20 individuals, composed of at least one male, several females and their offspring. A dominant male silverback heads the group, with younger males usually leaving the group when they reach maturity. Females transfer to another group before breeding, which begins at eight to nine years old; they care for their young infant for the first three to four years of its life. There is therefore a long interval between births, which partly explains the slow population growth rates that make the western gorilla so vulnerable to poaching. Due to the long gestation time, long period of parental care, and infant mortality, a female gorilla will only give birth to an offspring that survives to maturity every six to eight years. Gorillas are long-lived and may survive for as long as 40 years in the wild. Fruit forms a large part of the western gorilla's diet and they will travel further each day in search of fruiting trees than their eastern relatives. The distance that gorillas travel in the forest each day while they are searching for fruit trees varies between one and four kilometres. A group's home range may be as large as 30 square kilometres but is not actively defended. Wild western gorillas are known to use tools.
Deinonychus - Deinonychus antirrhopus
Deinonychus (/daɪˈnɒnɨkəs/ dy-NON-i-kəs; Greek: δεινός, 'terrible' and ὄνυξ, genitive ὄνυχος 'claw') was a genus of carnivorous dromaeosaurid dinosaur. There is one described species, Deinonychus antirrhopus. This 3.4 meter (11 ft) long dinosaur lived during the early Cretaceous Period, about 115–108 million years ago (from the mid-Aptian to early Albian stages). Fossils have been recovered from the U.S. states of Montana, Wyoming, and Oklahoma, in rocks of the Cloverly Formation and Antlers Formation, though teeth that may belong to Deinonychus have been found much farther east in Maryland. Paleontologist John Ostrom's study of Deinonychus in the late 1960s revolutionized the way scientists thought about dinosaurs, leading to the "dinosaur renaissance" and igniting the debate on whether dinosaurs were warm-blooded or cold blooded. Before this, the popular conception of dinosaurs had been one of plodding, reptilian giants. Ostrom noted the small body, sleek, horizontal posture, ratite-like spine, and especially the enlarged raptorial claws on the feet, which suggested an active, agile predator. "Terrible claw" refers to the unusually large, sickle-shaped talon on the second toe of each hind foot. The fossil YPM 5205 preserves a large, strongly curved ungual. In life, archosaurs have a horny sheath over this bone which extends the length. Ostrom looked at crocodile and bird claws and reconstructed the claw for YPM 5205 as over 120 millimetres (4.7 in) long. The species name antirrhopus means “counter balance”, which refers to Ostrom's idea about the function of the tail. As in other dromaeosaurids, the tail vertebrae have a series of ossified tendons and super-elongated bone processes. These features seemed to make the tail into a stiff counterbalance, but a fossil of the very closely related Velociraptor mongoliensis (IGM 100/986) has an articulated tail skeleton that is curved laterally in a long S–shape. This suggests that, in life, the tail could bend to the sides with a high degree of flexibility. Based on the largest known specimens, Deinonychus could reach at least 3.4 metres (11 ft 2 in) in length, with a skull length of 410 mm (16.1 in), a hip height of 0.87 metres (2 ft 10 in), and an estimated weight of 73 kilograms (160 lb). Its skull was equipped with powerful jaws lined with around seventy curved, blade-like teeth. Studies of the skull have progressed a great deal over the decades. Ostrom reconstructed the partial, imperfectly preserved, skulls that he had as triangular, broad, and fairly similar to Allosaurus. Additional Deinonychus skull material and closely related species found with good three-dimensional preservation show that the palate was more vaulted than Ostrom thought, making the snout far narrower, while the jugals flared broadly, giving greater stereoscopic vision. The skull of Deinonychus was different from that of Velociraptor, however, in that it had a more robust skull roof like that of Dromaeosaurus, and did not have the depressed nasals of Velociraptor. Both the skull and the lower jaw had fenestrae (skull openings) which reduced the weight of the skull. In Deinonychus, the antorbital fenestra, a skull opening between the eye and nostril, was particularly large. Deinonychus possessed large hands (manus) with three claws on each forelimb. The first digit was shortest and the second was longest. Each hind foot bore a sickle-shaped claw on the second digit, which was probably used during predation.
