Birds have colonized various habitats during their evolutionary history, including the aquatic environment. Several studies have investigated the gross morphological changes of the avian skeleton in response to increasing swimming capabilities, but few have documented in detail the microstructural specializations associated with this process. Bone microstructure is nevertheless often used to reconstruct the ecology of extinct aquatic birds, although this relationship is incompletely understood in modern forms, especially for the extent of intra-specific variability related, or not, to age. In an attempt to fill this gap, we investigated the change in limb bone microstructure from hatching to adulthood in 34 Aptenodytes patagonicus specimens. Our results reveal substantial intraspecific variability, regardless of the ontogenetic stage considered. Although most skeletal growth is achieved in the first few months after hatching, limb bone microstructure undergoes important maturation throughout ontogeny until fledging, which occurs in 1-year-old chicks. Architecture and compactness in hindlimb bones mature earlier than in forelimb bones, reflecting the time offset in the use of musculoskeletal elements involved in terrestrial locomotion in chicks (hindlimbs) and sub-aquatic locomotion in adults (forelimbs). These observations allow critical reassessment of previous palaeoecological reconstructions in extinct Sphenisciformes and set a good comparative framework for rigorous inferences.

中文翻译：

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王企鹅（Aptenodytes patagonicus）四肢骨微结构的个体发育（Miller，1778），考虑到企鹅形目的古生态学推论

鸟类在其进化历史中定居于各种栖息地，包括水生环境。一些研究调查了鸟类骨骼因游泳能力增强而发生的总体形态变化，但很少有研究详细记录与这一过程相关的微观结构专门化。然而，骨微结构经常被用来重建已灭绝水鸟的生态，尽管这种关系在现代形式中尚未完全理解，特别是与年龄相关或无关的种内变异程度。为了填补这一空白，我们研究了 34 只 Aptenodytes patagonicus 标本从孵化到成年的肢体骨微结构的变化。我们的结果揭示了显着的种内变异，无论考虑的个体发生阶段如何。尽管大多数骨骼生长是在孵化后的最初几个月内实现的，但肢体骨骼微观结构在整个个体发育过程中经历了重要的成熟，直到长出羽毛（发生在 1 岁的雏鸡中）。后肢骨骼的结构和致密性比前肢骨骼成熟得早，反映了参与雏鸡陆地运动（后肢）和成人水下运动（前肢）的肌肉骨骼元素使用的时间偏移。这些观察结果可以对先前灭绝的楔形目古生态重建进行批判性的重新评估，并为严格的推论建立一个良好的比较框架。