The Early Bird: Fossils Depict Aquatic Origins of Near-Modern Birds 115 Million Years Ago

Five fossil specimens of a near-modern bird found in the Gansu Province of northwestern China show that early birds likely evolved in an aquatic environment, according to a study reported today in the journal Science. Their findings suggest that these early modern birds were much like the ducks or loons found today. Gansus yumenesis, which lived some 105 to 115 million years ago during the Early Cretaceous period, took modern birds through a watery path out of the dinosaur lineage.

The report was co-authored by Peter Dodson of the University of Pennsylvania and his former students Hai-lu You of the Chinese Academy of Geological Sciences, Jerald Harris of Dixie State College of Utah and Matthew Lamanna of Carnegie Natural History Museum in Pittsburgh.

"Gansus is very close to a modern bird and helps fill in the big gap between clearly non-modern birds and the explosion of early birds that marked the Cretaceous period, the final era of the Dinosaur Age," said Peter Dodson, professor of anatomy at Penns School of Veterinary Medicine and professor in Penns Department of Earth and Environmental Sciences. "Gansus is the oldest example of the nearly modern birds that branched off of the trunk of the family tree that began with the famous proto-bird Archaeopteryx."

Gansus yumenensis takes its name from the Gansu region, where it was found, and the nearby city of Yumen. According to Dodson, Gansus is something of a lost species, originally described from a fossil leg found in 1983, but since largely ignored by science. The five specimens described by Dodson and his colleagues had many of the anatomical traits of modern birds, including feathers, bone structure and webbed feet, although every specimen lacked a skull.

"It appears that the early ancestors of modern birds lived lifestyles that today we would stereotype as being duck-like, heron-like, stork-like, loon-like, etc.," said Jerald Harris, director of paleontology at Dixie Sate College of Utah. "Gansus likely behaved much like its modern relatives, probably eating fish, insects and the occasional plan. We won't have a definitive dietary answer until we find a skull."

The skeletons, headless as they are, offer plenty of evidence for a life on the water. Its upper body structure offers evidence that Gansus could take flight from the water, like a modern duck, and the webbed feet and bony knees are clear signs that Gansus swam.

"Webbed feet is an adaptation that has evolved repeatedly in widely separate groups of animals, such as sea turtles, whales and manatees, and would only hinder climbing or landing in trees," Harris said. "The big bony crest that sticks off the knee-end of their lower leg bones are similar to structures seen in loons and grebes. These crests anchor powerful muscles needed for diving under water and swimming."

According to Harris, these adaptations all demonstrate how the Gansus branch of the family tree, the structurally modern birds called ornithuromorphs, split from the enantiornitheans (or "opposite birds"). Enantiornitheans were among the feathered fossils found in northeastern China during the 1990s.

"The enantiornitheans had the best adaptations for perching, so they were able to dominate the ecological niche that we would associate with songbirds, cuckoos, woodpeckers or birds of prey," Harris said. "Gansus appears to have had adaptations for a lifestyle centered around water, based on things like the proportions of the leg and foot bones."

While the enantiornitheans are now long gone, their perching lifestyle has now been taken over by the descendents of birds like Gansus. What remains a mystery for now, according to the researchers, is how the amphibious lifestyle of birds like Gansus helped enable them to survive the cataclysmic end of the dinosaurs 65 million years ago.

Funding was provided by the Discovery Channel (Quest program) and the Science Channel, the Carnegie Museum of Natural History, Dixie State College, the Chinese Geological Survey of the Ministry of Land and Resources of China and the Gansu Bureau of Geology and Mineral Resources.

Aquatic birds, eh? Hmmm. Wonder if they were good to eat?

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Some aquatic birds can be a bit rank-tasting.

Went hunting with a Cajun once. He shot a bunch of coots (he called them, "pouldoo") and took them home for his wife to cook.

She cooked the breasts and legs for hours in a dark brown gravy with more onions than there was bird meat -- until the meat literally fell off the bones. She then picked off the meat, added it to the gravy and served it over rice.

The gravy and rice were quite good -- but the meat was still a little too strong-tasting for me...

My Cajun friend "seasoned" his gravy with lots of some clear stuff from a fruitjar; by the time the meal was over, he was enjoying everything... '-)

Another article with more information, from here: Missing Link in Birds Believed Found. Copied in full:

Separating the layers of sediment from an ancient lake was like turning the pages of a book to get a glimpse of life in the time of dinosaurs, an international team of scientists said Thursday. "A world lost for more than 100 million years was being revealed to us," said Hai-lu You of the Chinese Academy of Geological Sciences.

What they found is being called the missing link on the evolution of birds, a loon-like creature that lived in northwest China and is the earliest example of modern birds that populate the planet today.

Before their discovery, reported in Friday's issue of the journal Science, the only evidence for this creature - Gansus yumenensis - was a single, partial leg discovered in the 1980s.

Now researchers have dozens of nearly complete fossils of Gansus, said a beaming Matt Lamanna of the Carnegie Museum of Natural History in Pittsburgh.

"Most of the ancestors of birds from the age of dinosaurs are members of groups that died out and left no modern descendants. But Gansus led to modern birds, so it's a link between primitive birds and those we see today," Lamanna said.

Previously there was a gap between ancient and modern species of birds, and "Gansus fits perfectly into this gap," added Jerald D. Harris of Dixie State College in Utah.

It was about the size of a modern pigeon, but similar to loons or diving ducks, the researchers said. One of the fossils even has skin preserved between the toes, showing that it had webbed feet.

"We were lucky far beyond our expectations" in finding these fossils, added You.

"Gansus is the oldest example of the nearly modern birds that branched off of the trunk of the family tree that began with the famous proto-bird Archaeopteryx," said Peter Dodson of the University of Pennsylvania.

The remains were dated to about 110 million years ago, making them the oldest for the group Ornithurae, which includes all modern birds and their closest extinct relatives. Previously, the oldest known fossils from this group were from about 99 million years ago.

The fact that Gansus was aquatic indicates that modern birds may have evolved from animals that originated in aquatic environments, the researchers said.

"Our new specimens are extremely well preserved, with some even including feathers," Lamanna said. "Because these fossils are in such good condition, they've enabled us to reconstruct the appearance and relationships of Gansus with a high degree of precision. They provide new and important insight into the evolutionary transformation of carnivorous dinosaurs into the birds we know today."

The remains were found in an ancient lake bed near the town of Changma.

"We went to Changma hoping that we'd discover one, maybe two, fragments of fossil birds," he said. "Instead, we found dozens, including some almost complete skeletons with soft tissues."

The new fossil material "is remarkable for its excellent preservation. ... The new fossils demonstrate that Gansus clearly is a bird that spent much of its life looking for food in water," commented Hans-Dieter Sues, associate director for research and collections at the Smithsonian's National Museum of Natural History.

Gansus is an additional "link in a long chain of intermediate forms between Archaeopteryx, the oldest known bird from the late Jurassic, and modern birds," said Sues, who was not part of Lamanna's research team.

Funding for the research was provided by the Discovery Quest program for The Science Channel, Carnegie Museum of Natural History, Dixie State College of Utah, the Chinese Geological Survey and the Ministry of Science and Technology of China.

At one point during the field work, Lamanna told his colleagues he would eat a duck foot if they found the fossil they were seeking while the television camera crew was still there.

So, did they?

"It tasted sort of like chicken, but real rubbery," he recalled.

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