Prehistoric giant reptiles never had feathers. A recent study has dealt a significant blow to the long-standing hypothesis that birds are direct descendants of bipedal carnivorous dinosaurs.
Published in the Journal of Morphology, the research team asserts that birds and dinosaurs may have shared a common ancestor among reptiles, but many scientists have previously drawn incorrect conclusions about the relationship between modern birds and prehistoric dinosaurs.
Alan Feduccia, the lead researcher, states that the real issue emerged in 1996, when an official from the National Geological Museum in Beijing announced a photograph purported to be of the first “feathered dinosaur” – a small dinosaur named Sinosauropteryx, which lived at the beginning of the Cretaceous period, around 127 million years ago.
Sinosauropteryx had some fossilized “filaments” on several bone fragments, which researchers in Beijing identified as precursors to feathers that may have evolved into the feathers found in modern birds. The next day, the New York Times published a major article, and since then, other news agencies have popularized the idea of feathered dinosaurs and their direct relationship with birds, “while in reality, there is no anatomical or biological evidence supporting this claim,” Feduccia, a professor of evolutionary biology and ornithology at the University of North Carolina at Chapel Hill, stated.
Feduccia’s team analyzed data from China and studied the structure and composition of collagen fibers in modern animals, such as snakes and lizards. The results showed that these collagen fibers, when degraded, leave similar traces to the “filaments” on dinosaur bones.
“The so-called proto-feathers appear to be nothing more than torn skin that has fossilized,” he mentioned. Feduccia also added that the Cretaceous dinosaurs in China appeared about 25 million years later than the earliest birds – Archaeopteryx (about 150 million years ago).
“Archaeopteryx had the brain of a bird, wings, and feathers almost identical to those of modern birds, so it is illogical to speculate that Cretaceous dinosaurs had feathers and were direct ancestors of birds, as feathered birds had already emerged prior,” Feduccia emphasized.
He also believes that Velociraptors and other small carnivorous species that resemble birds, with plumage and classified as dinosaurs, are actually just flightless birds.
Many scientists supporting the hypothesis that birds evolved from dinosaurs have pointed out that both groups of animals have a three-fingered system, comparable to the thumb, index, and middle fingers in humans.
However, the new study found that birds also have an additional index finger, middle finger, and “ring finger” arranged in their wings and on their feet. This is markedly different from bipedal dinosaurs, leading Feduccia to state that their findings have reinforced doubts about the hypothesis of birds evolving from dinosaurs.
Instead, he advocates the argument that birds and dinosaurs share a common ancestor but evolved independently along separate paths. Feduccia’s thorough research has garnered support from many scientists.
T. An (according to Discovery)