CNN —A peculiar fossil has helped scientists discover an unusual bird that lived among the dinosaurs 120 million years ago, and the find is changing the way researchers think about avian evolution. Enantiornithines are known as “opposite birds” because they had a shoulder joint feature that greatly differs from the ones modern birds have. “Before Imparavis, toothlessness in this group of birds was known to occur around 70 million years ago,” Clark said. When Jingmai O’Connor, the Field Museum’s associate curator of fossil reptiles, visited the Shandong museum’s collections a few years ago, the fossil caught her attention. While modern birds have fused forelimb digits, enantiornithines still had independent movement in the “little fingers” on their wings.

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Persons: Sir David Attenborough, ”, Alex Clark, Imparavis, ” Clark, Jingmai O’Connor, O’Connor, Clark, “, enantiornithines, ” O’Connor, ” Attenborough Organizations: CNN, University of Chicago, Field Locations: China, China’s Toudaoyingzi, Shandong