New Discoveries Reveal Secrets of Rare Archaeopteryx Fossil and Early Bird Evolution

New Discoveries Reveal Secrets of Rare Archaeopteryx Fossil and Early Bird Evolution

Researchers at the Field Museum of Chicago have made remarkable discoveries about a pigeon-sized Archaeopteryx fossil in their collection. This fossil exhibits features previously unknown, shedding light on the earliest known birds, particularly concerning feather structure, limb anatomy, and cranial characteristics.

According to a recent Reuters report, this specimen is one of the best preserved and most complete examples among the 14 known Archaeopteryx fossils discovered since 1861. Its exceptional condition provides new insights into the evolutionary journey from dinosaurs to birds.

The initial discovery of an Archaeopteryx fossil demonstrated a blend of reptilian and avian traits, thereby supporting Charles Darwin’s theories on evolution. This fossil illustrated how birds evolved from dinosaurs, reshaping our understanding of avian ancestry.

Advanced Techniques Reveal Fossil Details

Using ultraviolet light, scientists were able to identify soft tissues within the Chicago fossil, while CT scans revealed details concealed within the surrounding rock. This groundbreaking study emphasizes that even after 164 years since the first Archaeopteryx fossil was found, significant discoveries about this winged creature from the Jurassic period, approximately 150 million years ago, continue to emerge.

The analysis indicates that although Archaeopteryx had the ability to fly, it likely spent much of its time on the ground and possibly climbed trees. Furthermore, the fossil revealed specialized feathers known as tertials on both wings. These particular feathers attach to the humerus bone in the upper arm and represent the innermost layer of flight feathers.

The Significance of Tertial Feathers

Interestingly, small-feathered dinosaurs did not possess these tertial feathers. Researchers propose that the presence of these inner flight feathers in Archaeopteryx suggests they evolved specifically to enhance flight capabilities.

Field Museum paleontologist Jingmai O’Connor explained that for effective flight, the aerodynamic surface must be continuous with the body. She noted, “In order for flight using feathered wings to evolve, dinosaurs had to fill this gap, as we see in Archaeopteryx.”

Despite over 160 years of research on Archaeopteryx, essential information remains contentious. The presence of tertials reinforces the idea that this creature was indeed a bird capable of flight.

Unique Three-Dimensional Preservation

Unlike many fossils that are flattened, this specimen was preserved in three dimensions, allowing scientists to carefully prepare the soft tissue remains while keeping them intact. The application of ultraviolet light caused the tissue to glow, revealing its structure and composition.

Anatomical Features of Interest

Scientists observed soft tissue on the creature’s hands, indicating that the first and third fingers were agile and likely useful for climbing. Moreover, the soft tissue found on its toe pads suggests that Archaeopteryx spent considerable time on the ground and had limited flying capabilities.

Insights into Cranial Structure

Researchers also detected features within the palate, or the roof of the mouth, confirming that Archaeopteryx’s skull lacked mobility, unlike many contemporary birds. However, evidence supports the early stages of a trait that allows the beak to move independently of the braincase, a characteristic seen in modern avian species.

New Discoveries Enhance Fossil Knowledge

The Chicago fossil also holds the only known vertebral column of an Archaeopteryx, showcasing two tiny vertebrae at the tail’s tip, evidence of a total of 24 vertebrae—one more than previously believed.

Acquired by the museum last year, this fossil was in the possession of various private collectors since its discovery prior to 1990. O’Connor asserts, “This specimen is arguably the best Archaeopteryx ever found, and we’re learning a ton of new things from it.”

Historical Context of Archaeopteryx Findings

In March 2018, it was suggested that Archaeopteryx could fly, but in a manner distinct from that of modern birds, likely engaging in rapid, short flights over limited distances.

While possessing feathers akin to contemporary birds, Archaeopteryx also featured a long, stiff tail and dentition, alongside unfused bones in its hands, shoulders, and pelvis. Of the twelve identified fossils, the first was uncovered in the late 19th century by renowned German paleontologist Hermann von Meyer. The most recent fossil was found by an amateur collector in 2010 and was scientifically described in 2018.

As research continues, the discoveries linked to the Archaeopteryx fossil not only enrich our understanding of avian evolution but also emphasize the intricate connections between dinosaurs and modern birds.

Reuters contributed to this report.