What dinosaurs have been discovered in Antarctica?
Along with the hadrosaur mentioned above, there have been several discoveries of dinosaurs in Antarctica. For example, a 12-foot- (4-meter-) long, bipedal, plant-eating iguanodontid was discovered in February 1999 on a rocky beach of James Ross Island. A 70-million-year-old bipedal, meat-eating dinosaur (an unnamed theropod) was also discovered on James Ross Island in late 2003. The discoveries included a lower leg and foot bones, fragments of the upper jaw, and some teeth. Still another dinosaur, a 200-million-year-old bipedal, long-necked, plant-eating, unnamed sauropod was discovered in 2003 in the Antarctic interior, including fossils of a pelvis and one of the dinosaurs hipbones.
What English island continues to be a hotspot for dinosaur fossil discoveries?
The small Isle of Wight, 3 miles (4.8 kilometers) off the southern coast of England, became a major hotspot for paleontologists, and it continues to be one of the worlds best dinosaur fossil discovery sites. This island was once home to Queen Victoria, and is best known as a holiday destination. But the quality of its dinosaur fossils and the time period from which they originate make this island the focus of paleontologists worldwide. The uniqueness of the dinosaur fossils found on the Isle of Wight has to do with their numbers and age: over 20 species of dinosaur having been recognized from the Early Cretaceous (in particular between 110 and 132 million years ago). Fossils from this period are rare; most sites around the world yield fossils from the Triassic or Jurassic periods. Thus, the Isle of Wight dinosaur fossils are essentially a window into a unique period of time, and the island constitutes a resource not found elsewhere in the world. In addition, the fossils are well-preserved and articulated, meaning the bones are still joined together, not strewn around.
Why are dinosaur fossils relatively easy to find on the Isle of Wight?
The dinosaur fossils on the Isle of Wight are relatively easy to find because they are concentrated in two small areas. There is a 6-mile- (10-kilometer-) long fossil-containing area along the southern coast of the island, and another half-mile- (0.8-kilo- meter-) long area on the eastern coast. In many other of the top fossil sites in the world, the bones of dinosaurs are distributed over thousands of square miles, making the search for them more diffuse and difficult.
The continual uncovering of dinosaur bones on the Isle of Wight is due to a unique combination of physical factors. The rock containing the dinosaur bones has been pushed to the surface by geological pressures; in other parts of the world, this type of rock may be buried underground sometimes by as much as 1,000 feet (305 meters) below the surface.
The fossil-bearing rock itself is a soft rock, consisting mainly of sandstones and mudstones, which makes the rock susceptible to erosion. And the Isle of Wight experiences extensive erosion. More than three feet (one meter) of rock is worn away every year in certain exposed areas. The engine for this high rate of erosion is the sea. Every fall and winter, the flow of the tides, combined with high seas and gales from the English Channel, batter the rocks that make up the sea cliffs on the island. But this has been a boon to scientists: the erosion exposes dinosaur bones, which literally fall onto the beaches at the feet of eagerly awaiting paleontologists.
Two factors make dinosaur fossil hunting on Englands Isle of Wight rather easy: the fossils are concentrated in two small areas, and the island is made up of soft rock that is easy to excavate, such as the chalk on these cliff faces (iStock).
Among the many exciting finds on the Isle of Wight are: the skeleton of the first small, meat-eating dinosaur found in England, a new species, was found in a crumbling cliff by an amateur collector; in 1997, a smaller version of a Tyrannosaurus rex, another new species called Neovenator salerii, was also discovered; and a very well preserved Iguanodon was uncovered. The fossil remains of a 12-foot (4-meter) carnivorous dinosaur were discovered a cat-like creature, with unusually long hind legs that permitted it to run at high speeds; it was also equipped with claws and razor-sharp teeth and became the first small meat-eating dinosaur found in Britain.
What was Valdosaurus?
Valdosaurus (Wealden Lizard) was a small- to medium-sized ornithopod dinosaur whose remains have been found on the Isle of Wight. Only a few partial, fragmented remains have been found over the years. What little evidence there is suggests that this dinosaur was about 14 feet (4.25 meters) long and about 4 feet (1.2 meters) high at the hips. The excavated leg bones of Valdosaurus are comparable to those of Dryosaurus, a dryosaurid (oak lizard) known from the Late Jurassic period of North America, which lived some 30 million years earlier. Using Dryosaurus as a guide, Valdosaurus may have been a fast-running biped with long hind legs, short front limbs, a small skull, and stocky build. From the shape and size of the hind limb bones, we know that Valdosaurus was an agile and fast runner; there is currently no evidence of any armor plates, sharp teeth, horns, or claws. Thus Valdosaurus probably was a grazing dinosaur, eating ferns and cycad- like fronds. But it remained continually alert for predators, using its running ability as a defense against attacks.