08 December 2015
Slabs for Writing
The preservation of exquisitely fragile animals like birds (and pterosaurs, silly flying animals) is usually done with such fine sediments that the fossils are often found and removed as slabs of material. After those slabs are opened there is typically a slab, holding the actual fossil, and a counterslab that holds an impression of the fossil; this is where our wonderful feather impressions are most often found, though they have been known to come from the slab containing the fossil as well. Many of the remains of Jeholornis that have been procured, and certainly the ones that have been described, are found in this kind of arrangement. This is the reason also that so many of those papers are wonderfully descriptive and have such beautiful, for a crushed fossil bird, images of the fossil remains that are being described at the time. These include comparison papers between birds (Archaeopteryx vs. Jeholornis) as well as the straight descriptions of Jeholornis.