Science Dinosaurs died out before placental mammals lived | Dinosaurs died out before placental mammals lived |
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| by William Atkins | |
| Friday, 22 June 2007 | |
      
Two recent stories about the Creation Museum, in Petersburg, Kentucky, U.S.A., and its view on the relationship between dinosaurs and humankind is found at the MSNBC website titled “High-tech museum brings creationism to life: Biblical account is taken as scientific gospel at $25 million Creation Museum” and the New York Times website titled “Adam and Eve in the Land of the Dinosaurs”. U.S. researchers led by curator John Wible of the Carnegie Museum of Natural History (Pittsburgh, Pennsylvania) have performed a comprehensive investigation into the origins of placental mammals, or mammals that bear live young, which are nourished before birth in the mother’s uterus through the placenta, an embryonic organ attached to the uterus wall. Placenta mammals include almost 4,000 different species such as rodents, bats, elephants, whales, dogs, cats, cows, horses, and humans. They do not include such mammals like marsupials and egg-laying mammals such as the platypus. Wible’s team studied the skull of a shrew-like animal that was discovered in the Mongolia’s Gobi Desert over ten years ago. From this study, which involved fossil analysis and research of records from the Cretaceous Period that ranged from 145 to 65 million years ago, the team concluded that placental mammals originated about 65 million years ago. The Cretaceous Period began at the end of the Jurassic Period (about 145 million years ago) and ended at the start of the Teriary Period (about 65 million years ago). The research team compared the Mongolian skull, belonging to the species Maelestes gobiensis, with 409 features such as teeth, skeletal remains, and skulls of other animals ranging in ages from those living today to those who had lived 100 million years ago. They agreed with the “explosive theory” or “short fuse theory”, which states that placental mammals exploded onto the Earth after the demise of dinosaurs. This quick appearance of new species occurred because of the void left by dinosaurs. The results from the Wible team are found in this week’s issue of the journal Nature. Scientists generally agree with the study, finding it a most comprehensive analysis of the evolution of placental mammals. However, some are still quibbling about the exact time that placental mammals began to roam the Earth. Some contend that 100 million years ago is a more accurate frame of time rather than 65 million years ago. Other scientists have produced studies that determined some species of mammals were around as the dinosaurs were dying off. One such study is the research led by U.S. biologist David Archibald, of the San Diego State University in California. He suggests that some lineages to modern mammals appeared before the dinosaur became extinct. Scientists generally state that fossils and nuclear dating technology show that the Earth is more than four billion years old, the first dinosaurs appeared around 200 million years ago, and they died out well before the first human ancestors originated a few million years ago. Some creationists have the viewpoint that humankind and dinosaurs both roamed the Earth about 6,000 years ago (a "young creationist" viewpoint"), a belief shared by the Creationist Museum, mentioned earlier, whose website is: http://www.creationmuseum.org/. [Note: Modified 6/22/07 2:28 p.m. CDT.] {moscomment} |
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