Thursday, May 10, 2012

TORVOSAURUS :THE JURASSIC KING

Torvosaurus is a genus of large theropod dinosaur that lived during the Late Jurassic period (mid-late Kimmeridgian stage in North America, early Tithonian stage in Europe). The nameTorvosaurus means "savage lizard" and is derived from the Latin torvus ("savage") and the Greek σαυρος/sauros ("lizard").
 TORVOSAURS UP
ALLOSAURS DOWN 
Fossilized remains of Torvosaurus have been found in North America and Portugal. Torvosaurus reached 9 to 11 meters (30 to 36 ft) in length and an estimated weight of about 2 metric tons (2.2 tons), which made it the largest carnivore of its time, except for Epanterias (which may have been just a big Allosaurus) andSaurophaganax.
It was first discovered by James A. Jensen and Kenneth Stadtman in the rocks of the Morrison Formation at the Dry Mesa Quarry, Colorado in 1972. The genus and the type species T. tanneri were named and described in 1979 by Peter M. Galton and Jensen. The type specimen from Colorado was further described by Brooks Britt, and the Portuguese specimen by O. Mateus and M.T. Antunes.The size of Torvosaurus is not definitely known because only incomplete material has been found, but it was a large theropod. North American Torvosaurus material is estimated as belonging to an individual about 9.0 meters long (29 ft), with a weight of about 1.95 metric tons (2.15 tons).Material from Portugal indicates even larger animals. In 2006 a nearly complete maxilla found in Portugal was assigned to Torvosaurus tanneri. It measured 63 cm in length (2.13 ft), significantly larger than the 47 cm (1.54 ft) long maxilla of the American specimen (total skull length 118 cm [3.87 ft]). Based on this, a skull length of 158 cm (5.18 ft) was estimated for the Portuguese specimen. This is comparable to the largest T. rex skulls, and makes Torvosaurus the largest known Jurassic theropod (surpassing Saurophaganax/Allosaurus maximus and Edmarka), and among the largest of all theropods. A partial femur from another individual belongs to an animal estimated as 11 m (36 ft) long.Torvosaurus is related to the earlier Megalosaurus but is seemingly more advanced. Its classification is still uncertain but its family Megalosauridae is most commonly held as a basal branch of Tetanurae, less derived than carnosaurs or coelurosaurs, and likely related to the spinosaurids.

Saturday, May 5, 2012

KELENKEN :THE TERROR BIRD


Kelenken is an extinct genus of giant flightless predatory birds of the family Phorusrhacidae or "terror birds".
These birds lived in the Middle Miocene, some 15 million years ago, in Argentina along with Argentavis. With a skull 28 inches (71 cm) long (including its 18 inch, 45.7 cm beak), it had the largest head of any known bird. The tarsometatarsus was about 45 cm long .Kelenken was one of the largest carnivorous birds of all time, possibly reaching 2.28 to 3 meters (7.5 to 10 feet) tall and weighing around 500 pounds (230 kg).It is not entirely clear how Kelenken captured and killed its prey. As a large flightless carnivore, Kelenken likely chased down and killed its prey with several bone-shattering blows from its massive beak. Another possibility is that it may have picked up its prey item, then proceeded to shake it vigorously in order break its back. It is also possible that Kelenken may have been a scavenger, driving off other animals with its impressive size, and ferocious looks.