A Texas scientist ruffled some feathers when he said he had found the first bird.
Login / Register
ORNo Account? Register here.
LYING IN A DRAWER in a steel cabinet, the dark brown bones of Protoavis look like the leftovers from somebody’s Kentucky Fried Chicken lunch. There is the wishbone, over there is part of a drumstick, and this one might be a wing. Sankar Chatterjee, the vertebrate paleontologist at Texas Tech University in Lubbock, lifts them gently, turning them this way and that. Holding the fossils next to modern bird bones, he says excitedly, “Look at this! They’re exactly the same.”
Chatterjee believes that this drawer of bones belongs not to just any bird but to a member of the first bird species ever—a pheasant-size creature that flew the skies over West Texas 225 million years ago, 75 million years before the currently accepted first bird. If he is right, he and Protoavis will write a new chapter in prehistory. But other paleontologists, particularly dinosaur experts, doubt that the Indian-born Chatterjee has found anything like the first bird, and his claim has touched off an acrimonious debate. In the opinion of many scientists, the bones are not those of a bird at all but rather those of a tiny tree-dwelling reptile that hadn’t even evolved feathers. A bird ancestor? Possibly. A bird? No way.
Dinosaur debates are nothing new. Since Darwin’s time, scientists have fought tooth and nail over lineage, extinction, and new species. Birds in particular have been a frequent point of contention. For much of this century, birds were thought to be the descendants of archosaurs—a large group from which dinosaurs, crocodiles, and pterosaurs were also derived. One theory held that birds and dinosaurs evolved side by side. The notion that birds evolved directly from dinosaurs—that they are the living descendants of a certain dinosaur—was proposed by a specialist from Yale University, John Ostrom. In the early seventies, he compared the 150-million-year-old bones of what was then (and still is) accepted as the earliest bird, Archaeopteryx, with those of a small dinosaur, Compsognathus. Between the two, he found 21 significant similarities. Ostrom’s idea that a bird is a living dinosaur took a while to be accepted but is now considered gospel, more or less, by most dinosaur specialists.
Chatterjee’s radical challenge to Ostrom started in the summer of 1983, when the Texas paleontologist was digging in Triassic (225-million-year-old) red beds near Post, sixty miles south of Lubbock. There he found the disarticulated remains of two animals that appeared to be small dinosaurs, but because he was collecting many specimens in a great hurry, he put the bones in a drawer to study later. Several months went by before he got back to them for a closer look, and he was amazed to see how birdlike they were. Among its features, Protoavis seems to have had a flexible wishbone, which would act as a spring for wing movement; a large breastbone with a keel to which strong breast and shoulder muscles would have been attached; and an upper beak that moved vertically for rapid eating, similar to modern birds. Protoavis had a few small teeth at the front of its beak, lacked feathers (at least, none were preserved), and had all of its “finger” bones (modern birds fly with a modified finger).
Chatterjee informed the National Geographic Society, a supporter of his fieldwork, of his suspicions, and the society flew an expert to Lubbock to analyze the find. As luck would have it, the person they contacted was the Archaeopteryx man, John Ostrom. In Lubbock for just two days, Ostrom examined the bones. Without much time for careful study, and possibly influenced by Chatterjee’s enthusiasm, he said the bones appeared birdlike.
Ostrom’s initial assessment marked the beginning of the battle of the birds. In August 1986, the National Geographic Society issued a press release declaring Protoavis the first bird. Articles appeared that same month in the New York Times, Nature, and Time and in Scientific American in October—all giving credence to the theory that Protoavis was a true bird. Instead of being honored by his peers, however, Chatterjee was criticized. In the academic world, it is considered unprofessional to publicize a major discovery before it has been subjected to extensive scrutiny.
Chatterjee’s handling of his find did little to advance his reputation or his claim for Protoavis. To begin with, he made no diagram of the bones in their site prior to collection, which is a standard paleontological technique. Then, he took his time—five years—to publish his first paper. When the article came out in June 1991, it appeared in Philosophical Transactions of the Royal Society of London—an unusual choice, since the journal’s reviewers were outside the United States and never saw the bones. (Chatterjee says this is standard procedure; journals rarely, if ever, request to see the actual bones.) Furthermore, the paper was not about the entire Protoavis skeleton but merely the skull. More sniping followed. In the opinion of some scientists, Chatterjee should have made the specimen more available. Some paleontologists who visited Tech also said Chatterjee hovered over them while they were examining Protoavis and that he would barely let them touch the fossil. Utter nonsense, he says.
Since the euphoria over the initial discovery, the debate in the press has swung against Chatterjee. A recent story in Discover pitted Chatterjee and Ostrom against one another, and Ostrom was characterized as being highly skeptical that the fossil is anything but a dinosaur. Other critics contend that the bones were crushed, making it possible to interpret them in different ways. “This is something that looks like it’s been jumped up and down on a couple of times and shaken up and had some parts of it taken away,” said paleontologist Jacques Gauthier of the California Academy of Sciences at San Francisco’s Golden Gate Park. But Chatterjee stands by his interpretation of the skeleton, his method of collecting (pulling as many bones as possible out of the hills and describing them later in the lab), and his choice of Philosophical Transactions. “After all,” he says, “they published Darwin’s papers.”
In the midst of the Protoavis brouhaha, Chatterjee remains philosophical. “I didn’t mind scientific controversy,” he says. “Science has its own form of natural selection.” He still believes that when other paleontologists have examined the specimens and papers and more Protoavis fossils are found, “the truth will come out.” He expects to complete a second paper on the rest of the skeleton by the end of the year. Whether it quells or stirs up the dispute remains to be seen.
Much is riding on the eventual placement of Protoavis in the dinosaur or bird family tree. If Chatterjee’s description proves correct, his name will go down in the science books alongside paleontologists such as his hero Alfred Romer, the influential expert on vertebrate evolution, and Edwin Colbert, the world-renowned author of Men and Dinosaurs (1968). If he’s proven wrong and Protoavis is just a birdlike dinosaur, he says he will acknowledge that the scientific method works, disproving incorrect theories. Since paleontology is a subjective, highly contentious science, it will take many years for anything like a definitive answer.
What is one to make of the naturalized Texan who has created such a stir? A native of Calcutta, the 49-year-old Chatterjee has studied fossils in India, China, Antarctica, and the United States. Originally a structural geologist studying plate techtonics, he attended University College in London, where at a professor’s suggestion he took up vertebrate paleontology. Sixteen years ago, Chatterjee emigrated to the U.S., working at the University of California–Berkeley, George Washington University, and the Smithsonian Institution before landing an assistant professorship at Texas Tech in 1979. Now, in Levi’s, Reeboks, and a chambray shirt, he fits easily into the good ol’ boy country of West Texas.
Chatterjee has had great success in finding and describing new fossils: a long-necked creature similar to Tyrannosaurus rex, which he named Postosuchus after the town of Post; Malerisaurus, a lizardlike dinosaur; plant-eating Technosaurus, the earliest bird-hip dinosaur found in this hemisphere; and an ostrichlike dinosaur, Shuvosaurus, named after Chatterjee’s youngest son.
“The Triassic is my bonus,” Chatterjee says. “When I came to Tech, I never realized that the Triassic would become such a big thing with this Protoavis and all the other specimens that came out of it.” Remarkably, of the animals coming from the Protoavis site, 90 percent are predators, according to Chatterjee. “It’s a very unnatural assemblage that shows the animals were caught in a surprise. What we believe happened was a flash flood that distributed the bones here. There are so many animals, and of Postosuchus, gosh, there are many different sizes—Mommy, Daddy, and all the babies. That’s real, real exciting, you know? Beauuutiful specimens.”
On the way to the Post site, Chatterjee delivers an impromptu lecture on the geology of the region: “See this black land? As we’re traveling along here, we go back in time. We will go into the Ogalalla formation, and then we’ll drop suddenly to the Triassic. There’s a tremendous time gap! We’ll jump from maybe twenty million years to something like two hundred and twenty-five million years.” Perpetually enthusiastic, Chatterjee believes that the state has tremendous fossil wealth. “If you go to the great museums like the Smithsonian and the Carnegie, you’ll see Texas fossils. But there’s no good comprehensive museum in Texas where the students can see fossils from Texas,” he says. “There should be a Texas collection. This is such a treasure, and we need to do more than just have it in a lab in the basement. The public should have the right to see it.”