Figure 1

Specimens of feathers in amber used in this study. Scale bars = 1 mm. (A) Baltic amber, Smf Be 370, yielded amino acids. (B) Spanish amber, CES 457. (C) Spanish amber, CES 426. (D) Burmese amber, specimen 1. (E) Burmese amber, specimen 2, yielded amino acids. (F) Burmese amber, specimen 3. (G) Burmese amber, specimen 4. (H) Burmese amber, specimen 5. The sixth specimen of Burmese amber was not photographed before destructive sampling.