from the world's big
Lasers solve the mystery of the missing quill.
- The famous fossilized feather found in the 1860s is from some unknown animal.
- The fossil's missing quill has long kept its identity unknown.
- We're just at the beginning of our awareness of feathered dinosaurs.
The case of the missing quill<p>One of the obstacles to a thorough understanding of the fossil has been that the feather it depicts has no quill, or calamus. Analysis of the calamus would have allowed scientists to ascertain the source of the feather on the animal from which it came. Was it a large primary wing feather, a secondary feather from the smaller secondary wing, or a tail feather called a primary covert?</p><p>When the discovery of the feather became public in 1862, the feather was described as having a calamus, and von Meyer drew it with one. However, there's nothing there to the naked eye or when the fossil is viewed under x-ray fluorescence or with UV imaging.</p><img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8xOTE0NzYzNS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYwNzUzMzY1M30.VWrfK1zY9r_ZOzIV8ej5rX2vDH7E5JP0JPj-HWT6IKw/img.jpg?width=980" id="e2a9a" class="rm-shortcode" data-rm-shortcode-id="97809264e53e10b2f84ce1d03cde9fd3" data-rm-shortcode-name="rebelmouse-image" />
Original drawing by von Meyer, top. Fossil under white light today, bottom
(Kaye, et al)
Enter Laser-Stimulated Fluorescence<p>A microscopic examination of the fossil revealed to the authors of the new paper, led by <a href="https://www.researchgate.net/profile/Thomas_Kaye" target="_blank" data-vivaldi-spatnav-clickable="1">Thomas G. Kaye</a>, that there <em>had</em> originally been a quill present, but that "past preparation had engraved around the outline of the feather and inadvertently prepared away the calamus at some unknown point in the past."</p><p>The LSF uses a high-powered laser to expose geochemical differences between the fossil and the stone background. The chemicals fluoresce with different colors. In the end, LSF was able to recover the geochemical halo left behind by the missing materials. The halo perfectly matched von Meyer's drawing, as well, providing even more confidence of its accuracy.</p><p>The feather is, in fact, a primary covert. But there's something else.</p><img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8xOTE0NzY1My9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYzMDIyOTg2NH0.VyblzUcjsEE2sSvaOgybYUv6U_fErs9iIwLAAjvciYc/img.jpg?width=980" id="22cbe" class="rm-shortcode" data-rm-shortcode-id="4b26b1739a1578ca573506e58b02f84d" data-rm-shortcode-name="rebelmouse-image" />
LSF image of feather fossil with calamus halo
(Kaye, et al)
The Archaeopteryx lithographica is not from an Archaeopteryx<p>In the years since the 1860s, other specimens of feathered dinosaurs have been found, including 11 or 12 specimens of <em>Archaeopteryx</em>, notably one residing in a Berlin museum. While the newly identified primary covert somewhat resembles the Berlin specimen's secondary feathering — its closest match among all existing <em>Archaeopteryx</em> specimens — they're clearly not the same.</p><img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8xOTE0NzY2Ny9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYzNzQ4NTI3M30.ZsOsEor88XLu2J7cEAEgYAxvKeqwg8TYXrbIUtrMgXA/img.jpg?width=980" id="fb509" class="rm-shortcode" data-rm-shortcode-id="9ad64d8b2fb950845080e752f6fc9e30" data-rm-shortcode-name="rebelmouse-image" />
Drawing of the 1860s feather superimposed over its closest match from the Berlin specimen
(Kay, et al)