Specimens of Archaeopteryx The end of the feather has an obtuse angle of 110°, while the barbs branch off from the rachis at an angle of around 25°. The barbs branch noticeably into barbules, as in the feathers of modern birds. The base of the feather consists of plumulaceous barbs which are unconnected to one another and result in a down-like appearance. This tuft of down led Griffiths to conclude that "Archaeopteryx" might have been endothermic in that it implies the use of thermal insulation. The feather is clearly asymmetrical, which has been interpreted by many scientists to be a clear indication of
Specimens of Archaeopteryx ähnlichen Federn bedeckten "" ("skeleton of an animal covered in similar feathers"). In German, this ambiguity is resolved by the term "Schwinge" which does not necessarily mean a wing used for flying. "Urschwinge" was the favored translation of "Archaeopteryx" among German scholars in the late 19th century. In English, "ancient pinion" offers a rough approximation. Hermann von Meyer learned of the discovery of what would later be known as the London Specimen before he published his analysis of the single "Archaeopteryx" feather. In September 1861 he wrote to the "Neues Jahrbuch" about being informed of the discovery by Friedrich Ernst