科学家发现古老梦幻鬼鱼
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“梦幻鬼鱼”化石及其复原图。澳大利亚维多利亚博物馆提供
我科学家发现最“老”完整硬骨鱼
将相关记录前推约800万年
我国科学家发现的一条“梦幻鬼鱼”引起了国际同仁的关注:这是迄今为止全球最古老的保存完整的硬骨鱼乃至有颌脊椎动物化石,为人们勾勒出一幅更加详细的硬骨鱼类起源与早期演化图谱,进一步填充了硬骨鱼类和其他有颌类之间的形态学鸿沟。
该成果由中科院古脊椎动物与古人类研究所朱敏研究员带领的课题组完成,将刊登在26日出版的《自然》杂志上。
同期配发述评文章称:朱敏等为解开围绕有颌类分化和硬骨鱼类起源的重重谜团“提供了一条活灵活现的古鱼”。“至关紧要的是,这条鱼代表着人类遥远祖先的一个分支,它不但罕见地被完整保存下来,而且出人意料的古老。”
朱敏告诉记者,在目前生存的脊椎动物中,有颌脊椎动物的种数占99.7%以上,而其中隶属硬骨鱼纲的超过98%。“有颌类的早期分化以及硬骨鱼纲的起源与早期分化,在脊椎动物演化史上占有非常重要的位置。”但此前发现的化石大都属于距今约3.59亿—4.16亿年的泥盆纪,而且很不完整,研究者往往处于
“盲人摸象”的状态。
经过近20年的努力,课题组于2008年在云南曲靖的志留纪(4.16亿—4.44亿年)地层中发现了一件近乎完整的硬骨鱼标本。他们将其命名为“梦幻鬼鱼”,意为一条“来自梦里、拥有原始有颌脊椎动物梦幻特征组合的古鱼”。
“"梦幻鬼鱼"的发现,将最古老的近乎完整的硬骨鱼化石记录向前推进了约800万年。”朱敏说。
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