Data from: The plumage and colouration of an enantiornithine bird from the Early Cretaceous of China

Brilliant colour displays and diverse feather morphologies that are often
sexual ornaments are common throughout much of extant Avialae. Here we
describe a new basal enantiornithine bird specimen recovered from the
Early Cretaceous Jiufotang Formation of Liaoning Province in northeastern
China. We present new information on the plumage of Bohaiornithidae as
well as the first detailed colour reconstruction of an enantiornithine
bird. The new specimen retains subadult skeletal characteristics,
including periosteal pitting of the long bone epiphyses and unfused
elements, while also preserving plumage evidence consistent with sexual
maturity at the time of death. Exceptionally-preserved feathers cover the
body, including elongate crown feathers, body contour feathers,
asymmetrically-veined wing primaries, an alula and two elongate
rachis-dominated rectrices that may have been sexual ornaments. The crown,
neck, and body contour feathers retain elongate melanosome morphologies
associated with weakly iridescent colouration in extant feathers. We
provide additional evidence of preserved melanin using Raman spectroscopy;
a rapid, non-destructive chemical technique. The new specimen provides
data on skeletal ontogeny in the Bohaiornithidae as well as evidence for
intraspecific communication functions of plumage.

现存鸟翼类（Avialae）的大部分类群普遍具有绚丽的色彩展示和多样的羽毛形态，这些特征常作为性装饰。在此，我们描述了一件采自中国东北辽宁省早白垩世九佛堂组的反鸟类（enantiornithine bird）基干新标本。我们提供了关于渤海鸟科（Bohaiornithidae）羽毛的新信息，以及首个反鸟类的详细色彩重建结果。该新标本保留了亚成体的骨骼特征，包括长骨骨骺的骨膜凹陷和未愈合的骨骼元件，同时也保存了与其死亡时性成熟状态相符的羽毛证据。标本全身覆盖着保存异常完好的羽毛，包括延长的冠羽、体羽、具有不对称羽枝的初级飞羽、小翼羽，以及两根可能作为性装饰的、羽轴主导的延长尾羽。其冠羽、颈羽和体羽保留了延长的黑素体（melanosome）形态，这一形态在现存鸟类中与弱虹彩颜色相关。我们利用拉曼光谱法（Raman spectroscopy）——一种快速、非破坏性的化学技术——提供了黑素保存的额外证据。该新标本为渤海鸟科的骨骼个体发育提供了数据，同时也为羽毛的种内通讯功能提供了证据。