How did birds evolve? © Getty Images

How did birds evolve?

Birds are pretty impressive animals: they can fly, have an advanced vocal system and some can be as intelligent as primates. But how did they evolve?

Birds are pretty impressive animals: they can fly, have an advanced vocal system and some can be as intelligent as primates. For the past three decades, a mountain of genetic data and comparative studies of ancestral species has suggested that birds arose from ground-dwelling bipedal dinosaurs that gained the ability to fly through a number of small, slow biophysical changes that were up to now very poorly understood.

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A recent reexamination of an ancient sparrow-sized fossil from China by American paleontologists Stephen Czerkas and Alan Feduccia suggests that the ancestors of birds were in fact tree-climbing animals that existed well before the first dinosaurs.

The fossil of the Scansoriopteryx, (meaning “climbing wing”), has been identified as undeniably non-dinosaurian via the use of modern structural examination techniques, which allowed previously not visible skeleton parts to be inspected for the first time. The Jurassic fossil also shows many bird-like characteristics, including elongated forelimbs, wing and hindlimb feathers and clawed perching feet.

The fossiled remains of Scansoriopteryx and a reconstruction showing what a full skeleton would look like
The fossiled remains of Scansoriopteryx and a reconstruction showing what a full skeleton would look like

The researchers propose that Scansoriopteryx used its wing-like appendages for gliding from tree to tree, much like a modern day flying squirrel. Their findings support the theory first proposed in 1900 that birds evolved from small, gliding animals that evolved into true avian birds from the “tree down”.

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“The identification of Scansoriopteryx as a non-dinosaurian bird enables a reevaluation in the understanding of the relationship between dinosaurs and birds. Scientists finally have the key to unlock the doors that separate dinosaurs from birds,” explained Czerkas.