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近年来关于羽毛和羽状皮肤衍生物的研究极大促进了我们对羽毛起源与早期演化的理解。结合最新的古生物学与今生物学资料,对一些保存了皮肤衍生物的非鸟恐龙标本进行观察研究,为这个重要的进化问题提供了新见解。推测羽毛的演化在鸟类起源之前就以下列顺序完成了5个主要的形态发生事件:1)丝状和管状结构的出现;2)羽囊及羽枝脊形成;3)羽轴的发生;4)羽平面的形成;5)羽状羽小支的产生。这些演化事件形成了多种曾存在于各类非鸟初龙类中的羽毛形态,但这些形态在鸟类演化过程中可能退化或丢失了;这些演化事件也产生了一些近似现代羽毛或者与现代羽毛完全相同的羽毛形态。非鸟恐龙身上的羽毛有一些现代羽毛具有的独特特征,但也有一些现生鸟羽没有的特征。尽管一些基于发育学资料建立的有关鸟类羽毛起源和早期演化的模型推测羽毛的起源是一个全新的演化事件,与爬行动物的鳞片无关,我们认为用来定义现代鸟羽的特征应该是逐步演化产生的,而不是突然出现。因此,对于羽毛演化而言,一个兼具逐步变化与完全创新的模型较为合理。从目前的证据推断,最早的羽毛既不是用来飞行也不是用来保暖,各种其他假说皆有可能,其中包括展示或者散热假说。展开整合性的研究有望为羽毛的起源问题提供更多思路。
In recent years, research on feather and plume skin derivatives has greatly contributed to our understanding of the origins and early evolution of feathers. Combined with the latest palaeontology and biophysical data, the observation of some non-bird dinosaurs with skin derivatives has provided new insight into this important evolutionary issue. Predicting the evolution of feathers Five major morphogenetic events were completed in the following order prior to bird origination: 1) the appearance of filamentous and tubular structures; 2) the formation of feather sacs and feather spines; 3) the emergence of rachises; 4) the formation of feather plane; 5) plume feather branch. These evolutionary events form a variety of feather patterns that existed in various non-prey species but these patterns may degenerate or become lost during the evolution of birds; these evolutionary events also produce some similarities with modern feathers or with modern Feather exactly the same shape of feathers. The feathers of non-bird dinosaurs have some of the unique characteristics that modern feathers have, but there are also some features that are not present in bird feathers. Although some models of bird feather origin and evolution based on developmental data suggest that the origin of feathers is a completely new evolutionary event independent of reptile scales, we believe that the characteristics used to define modern bird feathers should evolve gradually Produced, not suddenly. Therefore, for feather evolution, a model that is both gradual and completely innovative is more reasonable. Judging from the current evidence, the earliest feathers were neither used for flight nor used to keep warm. Various other hypotheses are possible, including the demonstration or the cooling hypothesis. An integrated study is expected to provide more insight into the origins of feathers.