The historic fossil feather from the Jurassic Solnhofen has played a pivotal but controversial role in our evolutionary understanding of dinosaurs and birds. Recently, a study confirmed the diagnostic morphology of the feather’s original calamus, but nonetheless challenged the proposed identity as an Archaeopteryx covert. However, there are errors in the results and interpretations presented. Here we show that the feather is most likely an upper major primary covert, based on its long calamus (23.3% total length) and eight other anatomical attributes. Critically, this hypothesis is independently supported by evidence of similar primary coverts in multiple specimens of Archaeopteryx–including from the same fossil site and horizon as the isolated feather. We also provide additional insights, such as an updated colour reconstruction of the entire feather as matte black, with 90% probability. Given the isolated nature of the fossil feather, we can never know the anatomical and taxonomic provenance with 100% certainty. However, based on all available evidence, the most empirical and parsimonious conclusion is that this feather represents a primary covert from the ancient wing of Archaeopteryx.

侏罗纪索伦霍芬历史悠久的羽毛化石在我们对恐龙和鸟类的进化理解中发挥了关键但有争议的作用。最近，一项研究证实了羽毛原始菖蒲的诊断形态，但仍然挑战了作为始祖鸟隐蔽物的提议身份。但是，所呈现的结果和解释存在错误。在这里，我们表明羽毛很可能是上主要初级隐蔽，基于其长菖蒲（总长度的 23.3%）和其他八项解剖学属性。至关重要的是，这一假设得到了始祖鸟多个标本中类似初级隐蔽物的证据的独立支持– 包括来自与孤立羽毛相同的化石地点和地平线。我们还提供了其他见解，例如以 90% 的概率将整个羽毛更新为哑光黑色的颜色重建。鉴于化石羽毛的孤立性质，我们永远无法 100% 确定地知道解剖学和分类学的出处。然而，根据所有现有证据，最有经验和最简洁的结论是，这根羽毛代表了始祖鸟古代翅膀的主要隐蔽物。