Fossilized soft tissues are rare – even more rare are traces of internal organs (integument like skin and feathers being relatively more common). In an article published in the Proceedings of the National Academy of Sciences U.S.A., I described a specimen of Archaeorhynchus spathula, a primitive ornithuromorph bird, preserving traces of the lung tissue. Scanning electron…Read more "Fossilized lungs"
When an animal is preserved with evidence that it was rapidly buried by a collapsed sand dune, pyroclastic flow, or turbidite you can pretty safely assume that’s how the animal died. In fossils found in lake deposits we normally don’t know exact cause of death. However, two exceptional Early Cretaceous bird fossils from China preserve…Read more "Death by…"
Since it was described in a specimen of T. rex, medullary bone has been the center of much attention. Medullary bone is a tissue unique to living female birds and found only during the egg-laying cycle that forms in the medullary cavity (and other spaces) inside bones. Following the first description in T. rex, many dinosaurs and…Read more "A controversial bone tissue"
Modern birds (Neornithes) have a reproductive system that is highly modified compared to other amniotes. They are the only amniotes with a single functional ovary and oviduct (although within Aves there are a few exceptions, such as the Kiwi bird). I described nine fossil birds from the Jehol preserving remnants of the ovary. These specimens…Read more "Fossilized ovaries"
Although rare, stomach contents are the only way to be absolutely certain about predator-prey relationships in extinct ecosystems. I have described two specimens of Microraptor preserving ingested remains. One preserves the articulated remains of an enantiornithine bird; the other preserves the articulated remains of previously unknown species of lizard (named Indrasaurus wangi). These specimens together indicate that Microraptor was an…Read more "Microraptor’s last meal"