Post by Deinobrontornis on Oct 17, 2011 11:09:51 GMT -5
Megalodon - Carcachodon megalodon
The megalodon (meaning "big tooth") is an extinct species of shark that lived roughly from 28 to 1.5 million years ago, during the Cenozoic Era (late Oligocene to early Pleistocene).
Gottfried and colleagues (1996) also introduced a method to determine the body mass of the great white shark after studying the length–mass relationship data of 175 specimens at various growth stages and extrapolated it to estimate the body mass of C. megalodon. The proposed method is: mass in kilogram = 3.29E−06[TL in (meters)3.174]. According to this model, a 15.9 metres (52 ft) long C. megalodon would have a body mass of about 47 metric tons (52 short tons), a 17 metres (56 ft) long C. megalodon would have a body mass of about 59 metric tons (65 short tons), and a 20.3 metres (67 ft) long C. megalodon would have a body mass of 103 metric tons (114 short tons). Consequently, C. megalodon is regarded as the largest shark ever to have lived, and is among the largest fish known to have existed.
The exceptionally robust teeth of C. megalodon are serrated, which would have improved efficiency in slicing the flesh of prey items. Paleontologist Dr. Bretton K. Kent from University of Maryland suggests that these teeth are comparatively thicker for their size with much lower slenderness and bending strength ratios. They also have roots that are substantially larger relative to total tooth heights, and so have a greater mechanical advantage. Teeth with these traits are not just good cutting tools but also are well suited for grasping powerful prey and would seldom crack even when slicing through bones.
In 2008, a team of scientists led by Dr. Stephen Wroe conducted an experiment to determine the bite force of C. megalodon; results indicate that it had one of the most powerful bites in history. At 15.9 metres (52 ft) long, C. megalodon was capable of exerting a bite force estimated at 108,514 newtons (24,395 lbf), and at 20.3 metres (67 ft) long, C. megalodon was capable of exerting a bite force estimated at 182,201 newtons (40,960 lbf).
Sperm Whale - Physeter macrocephalus
Sperm whales (Physeter macrocephalus) are the largest of the odontocetes (toothed whales) and the most sexually dimorphic cetaceans, with males considerably larger than females. Adult females may grow to lengths of 36 feet (11 m) and weigh 15 tons (13607 kg). Adult males, however, reach about 52 feet (16 m) and may weigh as much as 45 tons (40823 kg).
The sperm whale is distinguished by its extremely large head, which takes up to 25 to 35% of its total body length. It is the only living cetacean that has a single blowhole asymmetrically situated on the left side of the head near the tip. Sperm whales have the largest brain of any animal (on average 17 pounds (7.8 kg) in mature males), however, compared to their large body size, the brain is not exceptional in size.
There are between 20-26 large conical teeth in each side of the lower jaw. The teeth in the upper jaw rarely erupt and are often considered to be vestigial. It appears that teeth may not be necessary for feeding, since they do not break through the gums until puberty, if at all, and healthy sperm whales have been caught that have no teeth.
Sperm whales are mostly dark gray, but oftentimes the interior of the mouth is bright white, and some whales have white patches on the belly. Their flippers are paddle-shaped and small compared to the size of the body, and their flukes are very triangular in shape. They have small dorsal fins that are low, thick, and usually rounded.
Because sperm whales spend most of their time in deep waters, their diet consists of many larger organisms that also occupy deep waters of the ocean. Their principle prey are large squid weighing between 3.5 ounces and 22 pounds (0.1 kg and 10 kg), but they will also eat large demersal and mesopelagic sharks, skates, and fishes. The average dive lasts about 35 minutes and is usually down 1,312 feet (400 m), however dives may last over an hour and reach depths over 3280 feet (1000 m).
The megalodon (meaning "big tooth") is an extinct species of shark that lived roughly from 28 to 1.5 million years ago, during the Cenozoic Era (late Oligocene to early Pleistocene).
Gottfried and colleagues (1996) also introduced a method to determine the body mass of the great white shark after studying the length–mass relationship data of 175 specimens at various growth stages and extrapolated it to estimate the body mass of C. megalodon. The proposed method is: mass in kilogram = 3.29E−06[TL in (meters)3.174]. According to this model, a 15.9 metres (52 ft) long C. megalodon would have a body mass of about 47 metric tons (52 short tons), a 17 metres (56 ft) long C. megalodon would have a body mass of about 59 metric tons (65 short tons), and a 20.3 metres (67 ft) long C. megalodon would have a body mass of 103 metric tons (114 short tons). Consequently, C. megalodon is regarded as the largest shark ever to have lived, and is among the largest fish known to have existed.
The exceptionally robust teeth of C. megalodon are serrated, which would have improved efficiency in slicing the flesh of prey items. Paleontologist Dr. Bretton K. Kent from University of Maryland suggests that these teeth are comparatively thicker for their size with much lower slenderness and bending strength ratios. They also have roots that are substantially larger relative to total tooth heights, and so have a greater mechanical advantage. Teeth with these traits are not just good cutting tools but also are well suited for grasping powerful prey and would seldom crack even when slicing through bones.
In 2008, a team of scientists led by Dr. Stephen Wroe conducted an experiment to determine the bite force of C. megalodon; results indicate that it had one of the most powerful bites in history. At 15.9 metres (52 ft) long, C. megalodon was capable of exerting a bite force estimated at 108,514 newtons (24,395 lbf), and at 20.3 metres (67 ft) long, C. megalodon was capable of exerting a bite force estimated at 182,201 newtons (40,960 lbf).
Sperm Whale - Physeter macrocephalus
Sperm whales (Physeter macrocephalus) are the largest of the odontocetes (toothed whales) and the most sexually dimorphic cetaceans, with males considerably larger than females. Adult females may grow to lengths of 36 feet (11 m) and weigh 15 tons (13607 kg). Adult males, however, reach about 52 feet (16 m) and may weigh as much as 45 tons (40823 kg).
The sperm whale is distinguished by its extremely large head, which takes up to 25 to 35% of its total body length. It is the only living cetacean that has a single blowhole asymmetrically situated on the left side of the head near the tip. Sperm whales have the largest brain of any animal (on average 17 pounds (7.8 kg) in mature males), however, compared to their large body size, the brain is not exceptional in size.
There are between 20-26 large conical teeth in each side of the lower jaw. The teeth in the upper jaw rarely erupt and are often considered to be vestigial. It appears that teeth may not be necessary for feeding, since they do not break through the gums until puberty, if at all, and healthy sperm whales have been caught that have no teeth.
Sperm whales are mostly dark gray, but oftentimes the interior of the mouth is bright white, and some whales have white patches on the belly. Their flippers are paddle-shaped and small compared to the size of the body, and their flukes are very triangular in shape. They have small dorsal fins that are low, thick, and usually rounded.
Because sperm whales spend most of their time in deep waters, their diet consists of many larger organisms that also occupy deep waters of the ocean. Their principle prey are large squid weighing between 3.5 ounces and 22 pounds (0.1 kg and 10 kg), but they will also eat large demersal and mesopelagic sharks, skates, and fishes. The average dive lasts about 35 minutes and is usually down 1,312 feet (400 m), however dives may last over an hour and reach depths over 3280 feet (1000 m).
