Monday, August 20, 2007

Not Dinosaurs - but just as ancient

Not Dinosaurs - but just as ancient  ======================= Reptiles of the Air ================ A small fluffy bird is about the last animal we would associate with the vast, scaly, terrifying dinosaurs. Yet birds appeared on Earth about the same time as the dinosaurs, and are quite closely related to them. The reptiles of the air were mainly gliders, not flyers. The leathery, batlike wings were weakly muscled and therefore lacked the powerful flying muscles that birds of today show. The very large ones must have had problems in flapping such huge wings, and probably flew by using currents of warm air that rise from the surface of the earth, this would allow them to soar. Archeopteryx as far as we know was one of the first birds to evolve. It had some body parts similar to the dinosaurs and others that were distinctly birdlike. It had feathers and could fly but was still very reptilian in many ways. Most obviously, its beak was filled with sharp reptilian teeth and its wings bore 4 long claws Pterandon had a wing-span of more than 5m, and half the length of its head consisted of a long bony crest, which may have been used as a rudder to guide and balance the animal whilst in flight Pterodactylus was a small, sometimes even sparrow-sized, wing fingered pterosaur. Like other of its group it had no tail, but had a long flexible neck. On land with their wings folded, some pterosaurs may have walked on their sharp toed feet whilst other may have used both their front and rear limbs. Quetzalcoatlus was the largest known pterosaur known, and had a wingspan of about 12m. The entire animal may have weighted 86kg, as much as a large human being! Rhamphorhynchus had a slender skull with forward pointing, spiky teeth. It's skull and hind legs show some similarities with those of the earliest dinosaurs. It had a short neck and long tail. This tail, strengthend by extra bony rods was used as a rudder when flying. Sordes appears to have had a thick, hairy coat, which would have kept the pterosaur warm during its flights. This is quite unusual as reptiles are normally covered in scales, mammals with hair, and birds with feathers! ============================================================== Reptiles of the sea ===================== While dinosaurs ruled the land for millions of years, some reptiles chose a life at sea. During the ago of the dinosaurs, the marine reptiles like icthyosaurs, pleiodaurs, pliosaurs, and the turtles were some of the fiercest and largest animals of the world's waterways Elasmosaurus was a remarkable long-necked pleiosaur. Its neck was more than half of its 13m in length and was made up of 40 (or more) bones, it is likely that with such a long neck it could bend it around like a snake in order to catch fast moving fish. Elasmosaurus fits the description of both ancient sea monsters and creatures like the famous modern-day "Loch Ness monster" Muraeonsaurus (another plesiosaur) found it easy to float in the sea because of its air-filled lungs, however it was not so easy for them to dive under water. Like deep-sea divers they needed weight to help them stay down in the sea, so they swallowed pebbles - just as crocodiles do today Ichthyosaurus with its flippers, fins and smooth, streamlined body was incredibly dolphin-like and this species was probably the acrobat of the seas. Kronosaurus was a huge pliosaur - 17m in length! Fossil evidence for this creature's existence has only been found in Australia Macroplata was was another fearsome pliosaur - with powerful paddles this enormous marine reptile flew through the sea. Peloneustes was a small short-necked pliosaur. It was only 3m long. Like other pliosaurs it probably hunted by hiding in wait for its prey and then diving quickly after it. Shonisaurus is the largest known icthyosaur known. It was a massive 15m long with a deep vast body. It lived about 210 million years ago Archelon was a gigantic 4m long turtle that lived near the end of the dinosaur era. Turtles, one of the oldest surviving groups of reptiles first appeared about 210 million years ago