Post by DinosaurMichael on Feb 28, 2012 19:33:57 GMT -5
Kodiak Bear - Ursus arctos middendorffi
The Kodiak bear (Ursus arctos middendorffi), also known as the Kodiak brown bear or the Alaskan grizzly bear or American brown bear, occupies the islands of the Kodiak Archipelago in South-Western Alaska. Its name in the Alutiiq language is Taquka-aq. It is the largest subspecies of brown bear. Few Kodiak bears have been weighed in the wild, so some of the weights are estimates. Size range for females is from 225 kg (500 lbs) to 315 kg (700 lbs) and for males 360 kg (800 lbs) to 635 kg (1400 lbs). Mature males average 480–533 kg (1,058–1,175 lb) over the course of the year, and can weigh up to 680 kg (1500 lbs) at peak times. Females are typically about 20% smaller and 30% lighter than males and adult sizes are attained when bears are 6 years old. Bears weigh the least when they emerge from their dens in the spring, and can increase their weight by 20–30% during late summer and fall. Bears in captivity can sometimes attain weights considerably greater than those of wild bears. An adult male Kodiak bear stands up to 1.5 m (5 ft) tall at the shoulder when it is standing on all four legs. When standing fully upright on its hind legs, a large male could reach a height of 3 m (10 ft). The largest Kodiak bear on record grew in captivity and died in the Cheyenne Mountain Zoo in December 1955, weighing 757 kg (1670 lb). They are the largest brown bear subspecies, and are comparable in size to polar bears. That makes Kodiak bears and polar bears both the two largest members of the bear family and the two largest extant wholly terrestrial carnivores. The standard method of evaluating the size of bears is by measuring their skulls. Most North American hunting organizations and management agencies use calipers to measure the length of the skull (back of sagittal crest on the back of the skull to the front tooth) and the width (maximum width between the zygomatic arches — “cheek bones”). The total skull size is the sum of these two measurements. The largest bear ever killed in North America was from Kodiak Island with a total skull size of 78.1 cm (30.75 in), and 8 of the top 10 brown bears listed in the Boone and Crockett record book are from Kodiak. The average skull size of Kodiak bears that were killed by hunters in the first five years of the 21st century was 63.8 cm (25.1 in) for boars and 55.4 cm (21.8 in) for sows. Although the term “Kodiak bear” is widely used to include all coastal Alaska brown bears, the subspecies only occurs on the islands of the Kodiak Archipelago (Kodiak, Afognak, Shuyak, Raspberry, Uganik, Sitkalidak, and adjacent islands). The Kodiak bear population was estimated to include 3,526 bears in 2005, yielding an estimated archipelago-wide population density of 0.7 bears/square mile (271.2 bears/1000 km²). During the past decade the population has been slowly increasing.
Utahraptor - Utahraptor ostrommaysorum
Utahraptor (meaning "Utah's predator" or "Utah thief") is a genus of theropod dinosaurs, including the largest known members of the family Dromaeosauridae. Fossil specimens date to the upper Barremian stage of the early Cretaceous period (in rock strata dated to 126 ± 2.5 million years ago). It contains a single species, Utahraptor ostrommaysorum. The holotype specimen of Utahraptor is fragmentary, consisting of skull fragments, a tibia, claws and some caudal (tail) vertebra. These few elements suggest an animal about twice the size of Deinonychus. Like other dromaeosaurids, Utahraptor had large curved claws on their second toes. One claw specimen is preserved at 22 centimetres (8.7 in) in length and is thought to reach 24 centimetres (9.4 in) restored. The largest described U. ostrommaysorum specimens are estimated to have reached up to 7 m (23 ft) long and somewhat less than 500 kg (1,100 lb) in weight, comparable to a grizzly bear in size. Some undescribed specimens in the BYU collections may have reached up to 11 m (36 ft) long, though these await more detailed study. It is thought that Utahraptor may be closely related to the smaller Dromaeosaurus and the giant Mongolian dromaeosaurid genus Achillobator. Although feathers have never been found in association with Utahraptor specimens, there is strong phylogenetic evidence suggesting that all dromaeosaurids possessed them. This evidence comes from phylogenetic bracketing, which allows paleontologists to infer traits that exist in a clade based on the existence of that trait in a more basal form. The genus Microraptor is one of the oldest known dromaeosaurids, and is phylogenetically more primitive than Utahraptor. Since Microraptor possessed feathers, it is reasonable to assume that this trait was present in all of Dromaeosauridae. Feathers were very unlikely to have evolved more than once in dromaeosaurids, so assuming that Utahraptor lacked feathers would require positive evidence that they did not have them. So far, there is nothing to suggest that feathers were lost in larger, more derived species of dromaeosaurs. In a 2001 study conducted by Bruce Rothschild and other paleontologists, 2 foot bones referred to Utahraptor were examined for signs of stress fracture, but none were found.
The Kodiak bear (Ursus arctos middendorffi), also known as the Kodiak brown bear or the Alaskan grizzly bear or American brown bear, occupies the islands of the Kodiak Archipelago in South-Western Alaska. Its name in the Alutiiq language is Taquka-aq. It is the largest subspecies of brown bear. Few Kodiak bears have been weighed in the wild, so some of the weights are estimates. Size range for females is from 225 kg (500 lbs) to 315 kg (700 lbs) and for males 360 kg (800 lbs) to 635 kg (1400 lbs). Mature males average 480–533 kg (1,058–1,175 lb) over the course of the year, and can weigh up to 680 kg (1500 lbs) at peak times. Females are typically about 20% smaller and 30% lighter than males and adult sizes are attained when bears are 6 years old. Bears weigh the least when they emerge from their dens in the spring, and can increase their weight by 20–30% during late summer and fall. Bears in captivity can sometimes attain weights considerably greater than those of wild bears. An adult male Kodiak bear stands up to 1.5 m (5 ft) tall at the shoulder when it is standing on all four legs. When standing fully upright on its hind legs, a large male could reach a height of 3 m (10 ft). The largest Kodiak bear on record grew in captivity and died in the Cheyenne Mountain Zoo in December 1955, weighing 757 kg (1670 lb). They are the largest brown bear subspecies, and are comparable in size to polar bears. That makes Kodiak bears and polar bears both the two largest members of the bear family and the two largest extant wholly terrestrial carnivores. The standard method of evaluating the size of bears is by measuring their skulls. Most North American hunting organizations and management agencies use calipers to measure the length of the skull (back of sagittal crest on the back of the skull to the front tooth) and the width (maximum width between the zygomatic arches — “cheek bones”). The total skull size is the sum of these two measurements. The largest bear ever killed in North America was from Kodiak Island with a total skull size of 78.1 cm (30.75 in), and 8 of the top 10 brown bears listed in the Boone and Crockett record book are from Kodiak. The average skull size of Kodiak bears that were killed by hunters in the first five years of the 21st century was 63.8 cm (25.1 in) for boars and 55.4 cm (21.8 in) for sows. Although the term “Kodiak bear” is widely used to include all coastal Alaska brown bears, the subspecies only occurs on the islands of the Kodiak Archipelago (Kodiak, Afognak, Shuyak, Raspberry, Uganik, Sitkalidak, and adjacent islands). The Kodiak bear population was estimated to include 3,526 bears in 2005, yielding an estimated archipelago-wide population density of 0.7 bears/square mile (271.2 bears/1000 km²). During the past decade the population has been slowly increasing.
Utahraptor - Utahraptor ostrommaysorum
Utahraptor (meaning "Utah's predator" or "Utah thief") is a genus of theropod dinosaurs, including the largest known members of the family Dromaeosauridae. Fossil specimens date to the upper Barremian stage of the early Cretaceous period (in rock strata dated to 126 ± 2.5 million years ago). It contains a single species, Utahraptor ostrommaysorum. The holotype specimen of Utahraptor is fragmentary, consisting of skull fragments, a tibia, claws and some caudal (tail) vertebra. These few elements suggest an animal about twice the size of Deinonychus. Like other dromaeosaurids, Utahraptor had large curved claws on their second toes. One claw specimen is preserved at 22 centimetres (8.7 in) in length and is thought to reach 24 centimetres (9.4 in) restored. The largest described U. ostrommaysorum specimens are estimated to have reached up to 7 m (23 ft) long and somewhat less than 500 kg (1,100 lb) in weight, comparable to a grizzly bear in size. Some undescribed specimens in the BYU collections may have reached up to 11 m (36 ft) long, though these await more detailed study. It is thought that Utahraptor may be closely related to the smaller Dromaeosaurus and the giant Mongolian dromaeosaurid genus Achillobator. Although feathers have never been found in association with Utahraptor specimens, there is strong phylogenetic evidence suggesting that all dromaeosaurids possessed them. This evidence comes from phylogenetic bracketing, which allows paleontologists to infer traits that exist in a clade based on the existence of that trait in a more basal form. The genus Microraptor is one of the oldest known dromaeosaurids, and is phylogenetically more primitive than Utahraptor. Since Microraptor possessed feathers, it is reasonable to assume that this trait was present in all of Dromaeosauridae. Feathers were very unlikely to have evolved more than once in dromaeosaurids, so assuming that Utahraptor lacked feathers would require positive evidence that they did not have them. So far, there is nothing to suggest that feathers were lost in larger, more derived species of dromaeosaurs. In a 2001 study conducted by Bruce Rothschild and other paleontologists, 2 foot bones referred to Utahraptor were examined for signs of stress fracture, but none were found.
