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Saturday, March 27, 2010
Dinosaurs' dominance 'aided by mass volcanism'
Immense volcanic activity aided the Dinosaurs rise to prominence some 200 million years ago, a study suggests.
Dinosaurs were the dominant vertebrates on land for about 135 million years.
While it is widely accepted that an asteroid or comet wiped them out, there has been less agreement on the factors which direct to their ascendancy.
Research in PNAS journal implies volcanic eruptions changed the climate, causing a mass Extinction of Dinosaurs' main competitors.
The scientific paper, by researchers from the US and Taiwan, come across at several lines of evidence such as the remains of plant wax and wood from sedimentary rocks interbedded with lava flows. From these, they were able to extract essential data about the climate at this time.
The lava flows are dated to the end-Triassic extinction, 201.4 million years before, which wiped out 50% of tetrapods (four-limbed animals) on land, 50% of terrestrial plants and 20% of marine families.
The scientists inspected how two different isotopes (or forms) of carbon fluctuated during these volcanic eruptions. They discover that the "heavy" form of carbon was depleted relative to the "light" form.
Labels: Dinosaur animals, Dinosaur reptile, Dinosaurs, Extinction of Dinosaurs
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Tuesday, February 16, 2010
Did dinosaurs evolve from birds or birds from dinos?
Study questions current evolutionary beliefs about birds
Latest study published in the Proceedings of the National Academy of Sciences proposes that Dinosaurs might actually have evolved from birds and not the other way around, as is commonly believed.
Oregon State University zoology professor John Ruben presents commentary about the study, which tested a latest specimen of raptor fossil discovered in 2003. The PNAS study reveled that the “small, feathered species must have been a ‘glider’ that came down from trees.”
The general and long-held belief that raptors and other ground-dwelling dinosaurs ultimately became birds is brought into question by the research, which Ruben says presents sound evidence that birds eventually became certain types of dinosaurs. For instance, the velociraptor so prominent in Jurassic Park might really have been a flightless bird.
Analysis of the feathers on the “microraptor’s” four limbs implies that the dinosaur probably couldn’t have taken off for ground-up flight, but were probably gliding from trees, “somewhat like a modern-day flying squirrel.” Ruben says this analysis builds it improbable that dinosaurs one day took to the skies but, rather, that birds one day touched down and stayed put, finally becoming dinosaurs.
Labels: Dinosaur animals, Dinosaur reptile, Dinosaurs, Extinction of Dinosaurs, First dinosaur
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Saturday, December 19, 2009
Dinosaurs come to the Waukegan Public Library
Volunteer Mitch Siegel of Waukegan helps assemble a T-Rex dinosaur skeleton as the Waukegan Public Library gets prepared for the "Dig the Dinosaurs" display, to celebrate the one-year anniversary of the Early Learning Center.
With the scratching sounds of a prehistoric jungle echoing overhead, visitors to the Waukegan Public Library's Early Learning Center are now being welcomed by a smile much toothier than they are accustomed to meeting.
To celebrate the one-year anniversary of opening the ELC, the Waukegan Public Library renovated its ELC facilities for three days and reopened them on November 15 with a new look and feel, gathering dinosaurs into nearly all facet of the space with "Dig the Dinosaurs."
Labels: Dinosaur animals, Dinosaur reptile, Dinosaurs, Extinction of Dinosaurs
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Monday, December 14, 2009
Bones show early divergence of dinosaur lineage
The early evolution of dinosaurs, in the late Triassic period, is fuzzy, to say the least.
Paleontologists recognize that the first dinosaurs emerge about 230 million years ago, but fossil evidence is so spotty that it is unapparent where and when the major lineages — theropods, sauropods and ornithischians — began to diverge.
Some excellent 215-million-year-old fossils unearthed in Ghost Ranch, in northern New Mexico, are aiding to clarify things. The bones, of a theropod that the discoverers have named Tawa hallae, offer strong support for the idea that the major lineages diverged early in dinosaur evolution in the part of the supercontinent Pangea that is now South America.
“What Tawa does is it helps intimate the relationships at the base of dinosauria,” said Sterling J. Nesbitt, a postdoctoral researcher at the University of Texas and lead author of a paper in Science describing the find.
Labels: Dinosaurs, Dinosaurs images, Extinction of Dinosaurs, First dinosaur
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Tuesday, December 8, 2009
Going Where the Dinosaurs Roamed in the United StatesExperts urge 'Westward Ho!' for finding the best dinosaur treasures
Experts urge 'Westward Ho!' for finding the best dinosaur treasuresThe gigantic brachiosaurus, the deadly and fierce tyrannosaurus, the nimble and fast velociraptor.
Millions of years ago, long before humans existed, these creatures - and many others like them -- wander the earth. We visited some of the territory where dinosaurs roamed in what is now the United States.
Morrison Formation, is a group of rock layers that is prime territory for dinosaur fossils. It is centered in the western U.S. states of Wyoming and Colorado. We start our exploration for the dinosaurs of North America at the Wyoming Dinosaur Center.
Malcom Bedell is a investigator at the center. His excavation team is digging up what he is pretty certain is a fossilized diplodocus - a large plant-eating dinosaur -- but it is slow and time-consuming work.
Labels: Dinosaur animals, Dinosaur reptile, Dinosaurs, Extinction of Dinosaurs
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