Archive for the ‘New Discoveries’ Category
How Do Flying Reptiles Fly?
Posted by: Avi in New Discoveries on January 7th, 2009
Pterosaurs are a group of winged reptiles that dies off 65 million years ago killed off the dinosaurs. Michael Habib, of the Center for Functional Anatomy and Evolution, has been researching how such large animals could possible fly. Computer simiulations that he has run seem to suggest that giant pterosaurs use all four limbs to get off the ground and into flight.
Todays birds get airborne by leaping off of their hind legs and flapping. Pterasaurs hind legs were far too weak and their bodies too massive to allow this type of takeoff to happen. It is also known that Pterosaurs walked on all four limbs from extensive fossil footprint evidence. This has lead Habib to think that they used their front legs to push off the ground for flight. He imagines a giraffe sized animal doing a leap-frog long jump and then snapping its wings out.
Other reseachers doubt that these winged dinosaurs would have been able to snap their wings out on time and think that a more likely way to achieve flight is to take a running jump off of a hieght as a hang glider might. Mark Witton, another Paleontologist, points out though that most Pterosaur finds are not near cliffs or other geological features suitable for the hang glider hypothesis and supports Habib’s view.
As the debate continues scientist and engineers watch to see if the latest research can help in design next generation aircraft that might use similar designs to the giant and extinct pterosaur.
Ancient armored amphibian had world’s oddest bite
Posted by: Avi in New Discoveries on December 16th, 2008
There existed 210 million years ago, an armored amphibian that has one of the stranges bites of all the animals ever. pulcherrimus opened its mouth not by dropping its lower jaw but by lifting back its head. Scientists think that this creature may have lived at the bottom of lakes and when a fish or other food swam by, it snapped its head up like a toilet seat to snatch up a meal. Due to a special adaptation of the joint between the skull and first neck bone, Gerrothorax could lift its head about 50 degrees relative to its lower jaw.
Gerrothorax measured about 3 feet long, had a flat head and body, and was protected by body armor. The jaws had sharp teeth and the roof of its mouth had fangs to keep prey from slipping out of its grasp. It is a member of a family of ancient amphibians called plagiosaurs. Although they were fairly successful at the time, having had fossils found in Greenland, Scandinavia and Europe, there are no modern descendants. It is most likely that they dissapeared during the extinction at the end of the Triassic period 200 million years ago.
New Fossil Sheds Light on the Evolution of the Turtle Shell
Posted by: Avi in New Discoveries on December 15th, 2008
In the Guizhou Province of southwestern China, Chun Li of the Chinese Academy of Sciences, has found a new fossil that may help explain the evolution of the turtle. The oldest known turtle species is from 210 million years ago and features a full top shell , called a carapice, and a bottom shell, called a plastron. The new fossil, named Odontochelys semistestacea, lived 10 million years earlier and has only a full bottom shell. The top shell is incomplete, with only bony extensions from the back bone and ribs.
Scientist used to think that a turtle shell evolved from scales that formed plates, which then fused into a shell. This new fossil evidence tells a different story of a shell forming from changes to the animals skeleton.
Bringing the Wooly Mammoth Back from Extinction
Posted by: Avi in New Discoveries on November 19th, 2008
What if we could bring back animals that are extinct to life, like in Jurassic Park? Well scientists think it may be possible to bring some animals back to life because of new DNA technologies.
DNA only lasts about 60,000 years so an animal we wanted to bring back would have to have lived no earlier than that (unfortunately Dinosaurs are much older). Scientists have started to look at the Wooly Mammoth, which died off about 10,000 years ago. Fossil finds of the Wooly Mammoth have produced hair, which can provide DNA segments that can be sequenced by the newest machines.
The problem is that scientists at this point cannot totally create new DNA from data about the sequence. What may be possible is to look at differences between the mammoth DNA and the DNA of its closest living relative, the African Elephant. There are about 400,000 differences between the elephant and mammoth genome. New technology may be available soon that could take an elephant’s DNA and just replace the 400,000 sections that need modification, place that DNA in an elephant egg and implant it into a female elephant. The female elephant would be pregnant and then give birth to the first mammoth to live since the last one died about 10,000 years ago.
There are still some hurdles to overcome though so don’t expect to see a Wooly Mammoth at your local Zoo anytime too soon.
The Full Article from the New York Times…
Why a Speeding Shark is Like a Golf Ball
Posted by: Avi in New Discoveries on November 10th, 2008
Shortfin mako sharks can swim at an amazing, 50 miles per hour. That is fast!!! But how do they do it? Scientists think they have discovered the answer.
The sharks have special scales across their skin that they raise up when they need to swim at a fast speed. This creates tiny wells on their body and actually helps them to move faster by reducing drag. It seems strange that by raising these minute scales that they could reduce drag (wouldn’t it create drag and make them slow down like millions of tiny parachutes?). But their scales work along the same principles as a golf ball does with it many dimples.
The idea is that the dimples on the golf ball and the scales on a shark create tiny whirlpools within the cavities. These whirlpools create a “buffer layer” between the surface of the shark and the fast moving water around it. Basically it is like moving a heavy box over marbles rather than dragging it across the floor.
The whirlpools also prevent a turbulent wake from forming behind the shark. A wake behind an object (for sharks as well as boats) has the effect of slowing it down and making harder to turn.
Scientists hope to use this discovery to design faster and more manuverable underwater vehicles and aircraft.
