Figure 1
From: Evidence corroborates identity of isolated fossil feather as a wing covert of Archaeopteryx
Centerlines of the isolated fossil feather and modern upper major primary coverts (UMPCs) from Kaye et al. 20198. (a) Modified from von Meyer 1862: Plate VIII, Fig. 33. (b) Laser-stimulated fluorescence image of MB.Av.100, modified from Kaye et al. 2019: Fig. 18. In (a) and (b), the centerline comprises the calamus (red) and rachis (blue), and the feather is oriented so that calamus endpoints are vertically aligned. Images are reversed to match (c). Scalebar: 1 cm. (c) Reproduced from Kaye et al. 2019: Fig. 38. The modern UMPCs presented here exhibit a strong anterior bend (leftward, towards the leading edge) near the calamus-rachis junction, creating an inflection point (S-curve) in the centerline. Note the yellow zone, representing the purported range of modern centerlines. (d) Modified figure from (c), including a more representative range of modern centerline morphologies (Common Crane X’ and XI’ from Supplementary Fig. S6, oriented so that calamus endpoints are vertically aligned). The correct Archaeopteryx centerline from (a,b) is overlaid as a solid blue line. This centerline was also overlaid onto the incorrect centerline to replicate the proximal end (red), revealing an alignment error. Note the substantial discrepancy between the correct and incorrect Archaeopteryx centerlines, the former of which now falls within the range of these modern primary coverts (yellow zone).
