Patriarch of the Aviary

For more than a century, many scientists have assumed that the forefather of all birds was a pigeon-size creature that looked like a dinosaur with feathers. Now, however, the 150 million-year-old Archaeopteryx has apparently been dethroned by a specimen named Protoavis ("first bird"), which lived 75 million years before Archaeopteryx. Last week's announcement was based on two fragmentary fossil skeletons found in the arid badlands of western Texas in 1984 by Texas Tech University Paleontologist Sankar Chatterjee. They suggest that Protoavis was a contemporary of the earliest dinosaurs. "If the identification is correct," says Yale Paleobiologist John Ostrom, who has examined the crow-size remains, "it has to send us back to the drawing board."

When unearthed in 1861 from a German quarry, Archaeopteryx seemed an ideal argument for the then new theories of evolution. Its reptilian brain and scaly head, combined with an avian wishbone and cloak of feathers, led many scientists to hail it as a missing link between reptiles and birds. But Protoavis has even more birdlike features than its younger cousin, Chatterjee believes. While both species have wishbones and forelimbs elongated into wings, he points out, the older fossil also has a bird's wide eye sockets, a large braincase and a breastbone designed to anchor muscles used in flight. Tiny bumps along Protoavis' forelimbs could indicate where feathers were attached. Explains Chatterjee: "Because some birds in the Cretaceous period (which began about 130 million years ago) were very modern, many scientists speculated that the first birds should be older than Archaeopteryx, yet more advanced. This is that bird."

His colleagues are more cautious about Protoavis' perch in the evolutionary tree, but most agree that it is a significant find. "It's hard not to make a bird out of it," says Paleontologist Nicholas Hotton III of the Smithsonian Institution. But he is reluctant to render a final verdict. If additional Protoavis specimens bolster Chatterjee's interpretation, it would indicate that birds appeared and diversified much earlier than scientists had believed. "Paleontology is like dealing with a 10,000-piece jigsaw puzzle for which you only have 15," says Ostrom. "This fossil gives you another 15 or 20 pieces of the puzzle."