A recently uncovered discovery at the Field Museum in Chicago has revealed a previously unknown feature within the skull of an Archaeopteryx lithographica fossil. The find, which took over a year to prepare, centers around the identification of oral papillae – fleshy structures on the roof of the mouth – and provides new insights into the evolution of feeding mechanisms in early birds and their dinosaur ancestors.
Unveiling the Hidden Anatomy
The Archaeopteryx fossil arrived at the Field Museum encased in limestone. A meticulous preparation process, beginning in and led by Akiko Shinya and her team, carefully removed the surrounding rock. Paleontologists utilized ultraviolet (UV) light during the preparation to highlight soft tissues, such as feathers and skin, without causing damage to the fossil. It was during one of these UV light stages that the unexpected structures were revealed within the skull.
“I remember them calling me over and saying, ‘Jingmai, we found something strange, come look at it,” said lead author Jingmai O’Connor, associate curator of fossil reptiles at the Field Museum. “They showed me these tiny, glowing dots, and I had no idea what we were looking at.”
These “dots” were identified as oral papillae, a feature previously undocumented in Archaeopteryx fossils.
The Significance of Oral Papillae
Oral papillae, present in modern birds, are fleshy cones lining the roof of the mouth. These structures aid in directing food towards the back of the throat, preventing it from entering the windpipe. While not teeth, they play a crucial role in efficient digestion. The discovery marks the oldest known instance of oral papillae in the fossil record, extending their known existence further back in time than previously understood.
“Imagine if the flesh on the roof of your mouth just had rows and rows of tiny, fleshy cones – that’s what birds have, and they’re called oral papillae,” explained O’Connor.
The presence of oral papillae in Archaeopteryx suggests that even these early bird-like dinosaurs possessed a specialized digestive system, potentially evolving to meet the high energy demands of flight. A discovery of a 127-million-year-old baby bird fossil also highlighted the early development of features seen in modern birds.
Evolutionary Implications for Flight
The discovery provides insight into how early birds adapted to the energetic requirements of flight. As dinosaurs evolved into birds, their bodies underwent significant changes to support powered flight. Efficient digestion became a key component of this adaptation. The presence of oral papillae in Archaeopteryx indicates that early avians were already developing the digestive efficiency seen in modern birds.
“These discoveries show this really clear shift in how dinosaurs were feeding when they started flying and had to meet the enormous energetic demands of flight,” O’Connor explained.
Modern birds possess highly efficient digestive systems, optimized for maximizing energy extraction from food. The presence of oral papillae in Archaeopteryx suggests an early step in this evolutionary process.
The Role of Advanced Preparation Techniques
The identification of the oral papillae was made possible by the advanced preparation techniques employed by the Field Museum team. UV light was instrumental in revealing features that would otherwise have remained hidden. This technique has become increasingly important in paleontological research, allowing scientists to uncover even the smallest and most intricate details within fossils. The team used UV light intermittently throughout the preparation process to ensure no soft tissues were damaged.
“The team used UV light during intermittent stages of fossil prep to make sure that they weren’t destroying any soft tissues,” says O’Connor. “Plus, some of these soft tissues and bone fragments are really tiny—they’re very, very easy to miss unless you’re actively looking for them.”
The meticulous work of the Field Museum team demonstrates the ongoing advancements in paleontological science and the potential for uncovering new insights into the prehistoric past. According to research from the University of California’s Museum of Paleontology, the fossil record of birds is not extensive, making each discovery particularly valuable. The Archaeopteryx, dating back , remains the oldest bird fossil on record, though other discoveries continue to refine our understanding of avian evolution. By , the research continues to bridge the gap between ancient dinosaurs and the birds we know today.
