Abstract Protopteryx fengningensis is from the 130–129 Ma (uppermost Hauterivian–lowermost Barremian, Lower Cretaceous) making it one of the oldest known enantiornithines. Contributing to its significance, this taxon is also commonly resolved as the basal-most enantiornithine in phylogenetic analyses. Protopteryx preserves several unusual morphologies that are otherwise absent in the Enantiornithes but common in the Ornithuromorpha such as the procoracoid and lateral processes on the coracoid and proximally convex humeral head. Thus, the morphology of this taxon hints at the morphology of the ornithothoracine common ancestor. Here we supplement existing data with information from a new specimen as well as new morphological data from the holotype and paratype. The new specimen preserves gaps in the right wing suggestive of a sequential molt. The presence of two gaps suggests that, unlike neornithines, primaries and secondaries molted simultaneously. This represents an intermediate condition between Microraptor, in which several feathers are growing simultaneously and sequentially, and modern birds with sequential molts, in which a single feather is replaced at a time. A single patch of feathers was sampled revealing preserved eumelanosomes, indicating that at least part of the remiges was darkly colored.

中文翻译：

---

来自新标本的原始鸟（Aves：Enantiornithes）羽毛的新信息

摘要 Protopteryx fengningensis 来自 130-129 Ma（最上层的 Hauterivian - 最下端的 Barremian，下白垩纪），使其成为已知最古老的对映鸟氨酸之一。由于其重要性，该分类群通常也被解析为系统发育分析中最基础的对映鸟氨酸。Protopteryx 保留了几种不同寻常的形态，这些形态在 Enantiornithes 中不存在，但在 Ornithuromorpha 中很常见，例如喙突和近端凸出的肱骨头上的前喙突和侧突。因此，该分类群的形态暗示了鸟胸科共同祖先的形态。在这里，我们用来自新标本的信息以及来自正模和副模的新形态数据补充现有数据。新标本保留了右翼的间隙，暗示了连续蜕皮。两个间隙的存在表明，与新鸟不同，初级和次级同时蜕皮。这代表了小盗龙（其中几根羽毛同时和顺序生长）和具有顺序蜕皮的现代鸟类（一次更换一根羽毛）之间的中间状态。对一片羽毛进行取样，揭示了保存下来的真黑素体，这表明至少部分残肢是深色的。