----- Original Message ----- From: Li'l Joe <[EMAIL PROTECTED]> To: Black-Left <[EMAIL PROTECTED]> Sent: Thursday, April 26, 2001 7:37 AM Subject: [downwithcapitalism] Paleontology : finding so-called "missing-links" Wednesday April 25 3:00 PM ET Dinosaur Fossil Had Feathers By RICK CALLAHAN, Associated Press Writer A duck-sized dinosaur fossil unearthed in China last year sports a downy coat from head to tail, bolstering evidence that feathers arose first for insulation and not flight, scientists report. The fossil, which will likely stoke the debate over the origin of birds, is the most complete of several found with feather-like features in China in recent years. It is dated between 126 million and 147 million years old. Lying in a slab of petrified mud, the skeleton is fringed with feathery impressions that researchers said were left by tufts of down and primitive feathers. One scientist said the downy coat suggests that it and other two-legged carnivores called advanced theropods were warm-blooded. ``There's strong evidence that these body coverings were originally insulation for warm-blooded dinosaurs and were only later co-opted for flight,'' said Mark Norell, chairman of the division of paleontology at the American Museum of Natural History in New York. The fossil, which was discovered last year and went on display Wednesday at the New York museum, is described in Thursday's issue of the journal Nature. Norell said the dinosaur was a dromaeosaur, a small, swift relative of the vicious Velociraptors portrayed in the film ``Jurassic Park''. Scientists have not determined if it represents a new species. A scientist who examined it last year in Beijing said he saw no evidence of feathers. ``To me it's the best specimen yet showing that these structures are not feathers,'' said Storrs Olson, curator of birds at the National Museum of Natural History at the Smithsonian Institution (news - web sites). ``There's nothing there that has a structure like a feather.'' Olson said the feather-like covering could be many things, including impressions of decaying skin or feathery mineral crystals common to many fossils. He also questioned Norell's contention that the fossil supports the case that theropods pioneered feathers before ancient birds. Olson notes that finds of feathered theropods all appear younger than the earliest known bird, Archaeopteryx, which had highly advanced feathers. But Norell said that because theropods date back at least 235 million years they likely developed primitive feathers well before Archaeopteryx, which is about 145 million years old. Olson and a minority of other scientists believe dinosaurs and birds had separate origins, putting them at odds with most scientists' position that birds arose from the small, meat-eating theropods. The new fossil was found in northeastern China's Liaoning Province, a fossil-rich region where animals were entombed in lake bottoms by volcanic ash. Thomas Holtz Jr., a vertebrate paleontologist at the University of Maryland, said he is particularly intrigued by herringbone patterns protruding from the fossil's arms and tail. The patterns suggest that structures such as barbs seen in modern feathers were organizing the feather fibers into adjacent rows of parallel lines. The fossil makes it increasingly plausible that theropods - including Tyrannosaurus rex - were fluffy and not scaly, at least in their adolescence, Holtz said. ``These things were fluffy, probably sort of like a kiwi bird today, from the snout to tail,'' he said. ``Sort of fuzzy killing machines.'' Richard O. Prum, curator of birds at the University of Kansas Natural History Museum, predicted the fossil will buoy the theory that birds evolved from dinosaurs. ``It is now impossible for any credible person to claim that birds are not theropod dinosaurs,'' he said. ``It's the final straw. We've all lived long enough for the dino-deniers to have to face the evidence. This comes as close to proof as we find in science.'' ************************************ Wednesday April 25 6:38 PM ET New Dinosaur Fossil Ruffles Feathers By Patricia Reaney LONDON (Reuters) - The discovery of a 130-million-year-old fossil of a feathered dinosaur provides dramatic evidence that birds evolved from the ancient reptiles, according to new research published on Wednesday. Paleontologists at the American Museum of Natural History in New York, where the fossil on loan from China has gone on display, believe the skeleton of a young dinosaur covered with primitive fluff is proof that the creatures developed feathers for warmth not flight and that dinosaurs evolved from birds. Dr. Mark Norell, chairman of the division of paleontology, said in a telephone interview that the fossil was about the size of a duck with a long tail. ``It shows us that these creatures looked more like weird birds than giant lizards,'' he said. The 2.5 foot long fossil, described in the journal Nature, was found by farmers in layers of volcanic and sedimentary rock of the Yixian Formation in China's northeastern Liaoning Province. It is a dromaeosaur -- a small, fast-running carnivorous dinosaur with a sickle-like claw on its middle toe. The creature is related to the mighty Tyrannosaurus rex and belongs to a group of dinosaurs called theropods -- two-legged predators with sharp teeth. Feathers have been found on dinosaurs which could not fly and which ``pre-dated the origins of birds and avian flight,'' the article in Nature said. Norell said the most reasonable explanation for the feathers was not for flight but for warmth. ``It's conceivable that smaller dinosaurs like this one and even the young of larger species like Tyrannosaurus rex may have needed feathers to keep warm,'' he said. Most Complete Fossil Of Feathered Dinosaur Until now most of the fossils of feathered dinosaurs, which were first discovered in 1995, have been incomplete. Scientists opposed to the theory that birds evolved from dinosaurs argued that the partial remains of the fluffy prehistoric creatures were not sufficient enough proof for the hypothesis. They believe birds evolved independently from a still undiscovered reptile. Ji Qiang, of the Chinese Academy of Geological Science which lent the fossil to the New York museum, said the discovery was particularly important because it showed the feathers were attached to the dinosaur's body. ``This is the specimen we've been waiting for. It makes it indisputable that a body covering similar to feathers was present in non-avian dinosaurs,'' he said in a statement. Theropod dinosaurs and birds share about 100 anatomical features, including a wishbone, swiveling wrists and three forward-pointing toes. Norell said dromaeosaurs were theropod dinosaurs thought to be most closely related to birds. *********************************** ===== Li'l Joe __________________________________________________ Do You Yahoo!? Yahoo! Auctions - buy the things you want at great prices http://auctions.yahoo.com/ Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
