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  3. Scientists have determined that Archaeopteryx, the earliest known bird, was

Scientists have determined that Archaeopteryx, the earliest known bird, was

游客2024-09-15  50
问题     Scientists have determined that Archaeopteryx, the earliest known bird, was definitely birdbrained, meaning no disrespect. Indeed, they consider the fossil’s brain size decisive evidence that Archaeopteryx had what it took to fly.
    The new research suggests, moreover, that birds probably started flying millions of years earlier than scientists previously thought. It is just that fossils of those first flying birds—predecessors of Archaeopteryx—have never been found.
    The researchers, at the Natural History Museum in London, based their findings on the first X-ray examination and reconstruction of the braincase and inner ear of a 147-million-year-old Archaeopteryx specimen. They found that in size, shape and volume, its brain was similar to that of the modern eagle or sparrow.
    Measurements of the semicircular canals, the mechanism for balance inside the ear, showed that Archaeopteryx had the "neurological and structural adaptations necessary for flight," the scientists concluded.
    Their research, involving an X-ray computed tomography scan, or C.T., of the fossil’s braincase and inner ear, is described today in the journal Nature.
    Previous studies of the feathered wing and tail of Archaeopteryx and its birdlike anatomy, including a pronounced wishbone, supported the prevailing view of experts that it was capable of some degree of powered flight. Archaeopteryx is considered a prime transitional species in the evolution of some reptiles, probably dinosaurs, into today’s birds.
    But the research team, led by Dr. Angela Milner, a paleontologist at the British museum, wrote that until their investigation of Archaeopteryx, "little was understood about the extent to which its brain and special senses were adapted for flight."
    Dr. Milner said the new study not only established that Archaeopteryx was capable of "controlling the complex business of flying," but also showed "how much there is still to discover about when and how bird flight began."
    In a statement issued by the museum, Dr. Milner said, "If flight was this advanced by the time Archaeopteryx was around, then were birds actually flying millions of years earlier than we’d previously thought?" [br] What do birds elove from, considering Archaeopteryx a transitional species?
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答案 Reptiles
解析 第6段最后一句提到了始祖鸟是爬行动物和鸟类的过渡物种，据此可说，鸟类是由爬行动物进化而来的，故答案是reptiles。
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