Researchers from the Institute of Vertebrate Paleontology and Paleoanthropology have made a groundbreaking discovery about early bird evolution. They analyzed a 120-million-year-old fossil of the extinct bird, Jeholornis, from China. This pheasant-sized bird, though resembling predatory dinosaurs, was found to be an arboreal plant-eater.
Microscopic analysis of the fossilized stomach contents revealed that Jeholornis had eaten leaves from magnoliid plants, such as magnolia, cinnamon, and avocado trees. This provides the oldest evidence of birds eating leaves, marking the earliest known evolution of arboreal plant-eating among birds.
The presence of gizzard stones in fossil skeletons allowed paleontologists to determine that some early birds consumed plant parts. Moreover, other Jeholornis fossils with fossilized fruit and seeds preserved in their digestive system offered more direct evidence of plants in their diet.
This study sheds light on the close ecological relationships between birds and flowering plants and how these interactions have evolved over time. The findings suggest that early birds switched from predatory behaviors to using their wings to fly into trees, consuming fruits, seeds, and leaves – a behavior observed in many bird species today.
In a pioneering effort, an international team of scientists explored the ancient stomach contents of an early bird to understand its diet. Employing a unique method, they searched for phytoliths – microscopic opaline silica structures produced by plants – to reveal what the bird had consumed.
After meticulously processing the fossilized stomach area, the researchers found hundreds of phytoliths, which turned out to be from magnoliid leaves. The absence of phytoliths in surrounding rock samples confirmed that these remnants truly represented the bird’s diet.
To strengthen their findings, the team compared the bird’s lower jaw to that of present-day birds with diverse diets. This analysis revealed similarities to birds primarily eating plants, reinforcing the conclusion that this early bird was indeed a leaf-eater.
The study highlights the long-standing connection between birds and flowering plants, dating back over 100 million years. Even in ancient times, birds were entwined with flowering plants, deriving energy for their active flight and vibrant feather colors from fruits, seeds, and leaves. This vegetarian, tree-living bird provides crucial insights into the fascinating evolution of birds and their dietary preferences throughout history.