Posted on 06/15/2006 11:39:26 AM PDT by PatrickHenry
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.
How can a bird with stone wings and feathers fly? It would be much too heavy. Sounds like a bad design to me.
Not sure how we would go about doing a double blind study with fossils but if you say so...
I realize that wasn't your point, but it does illustrate the different validation demands inherent in the various fields of science. While there is a possibility of a single scientist finding what he wants to find rather than interpreting the data accurately, the fossils are there for all scientists to see. Unless you are positing a huge conspiracy the chance that an incorrect or horribly biased interpretation will survive the scrutiny of many scientists, some who are at loggerheads with each other, is pretty thin.
Why? Because its not couched in absolute terms? Scientists aren't arrogant enough to assume they know everything and not all of us hinge our self image on rigidly held beliefs. Contrary to what you want to believe, life isn't about dichotomies.
If there were many skeptical scientists looking to see flaws in the logic of a particular piecing together of bone fragments, it would be a good thing.
You are correct you can't do double-blind studies, my point was that D-B studies are evidence that it is an accepted fact that even scientists will see what they are looking for. So in areas where you by nature are going to know what you are looking for, it takes a lot more skepticism and critical thinking.
It would be nice to see at least ONE scientist willing to hypothesize that this creature actually didn't have a skull, and see where it leads them.
Sure, it sounds stupid -- but to someone who is convinced of their position, many alternatives to what they think they see sound stupid.
In this sense, an evolutionist might argue that the politicized nature of the evolution debate makes it harder for real science becuase the scientists are afraid to ask too many skeptical questions since they fear the creationists will jump on those questions and use them to debunk evolution.
That is another danger that has to be dealt with -- the fear of aiding "the enemy" causing people to not question sufficiently.
No arguments against the findings...but I'm scratching my head over the conjecture regarding the findings.
Congratulations. I take it this is the very first time you have ever been right.
Well keep at it, you never know, you just might be right again.
Sure, it sounds stupid --
Boneheaded, actually...
I take it this is the very first time you have ever been right.
It's obvious you don't know me very well.
Usually the "intermediates" possess transitional features that are only seen in the artist reconstructions.
In this case, we see a "not-quite-beak" that's supposed to look somewhat reptilian - never mind that there is absolutely no evidence of this soft tissue feature, as there is absolutely no head of the specimen.
Why can't you scientists be more open-minded? Have you ever considered the possibility that these creatures lived within rocks? Just as they were found. Well, have you considered it? Huh? HUH!!! No, of course not. Because you're so biased in favor of your dogma! But we can see right through you. You're not fooling anyone. HAHAHAHAHA!!
</creationism mode>
You are absolutely correct. That is in fact why I have to take your posts as they are presented.
You were so gleeful at having 'guessed' a response that is given quite frequently to that particular creationist canard that I had to infer that this was your first time.
/creationism mode
Glad you put the "/creationism mode" tag in. Sometimes these days its hard to tell the difference.
Where do you see anything in the article about the beak on the missing head being "not quite?" Did the strawman put up a terrific fight?
A number of birds (ornithuromorphs like this find) from the late Cretaceous (Ichthyornis and Hesperornis for two) had teeth, so I'd incline to bet that this early Cretaceous version still had some chompers.
Couldn't have said it much better myself.
Why do you think this is anything other than a duck? Apparently, the allegation that it's a gabillion years old has no bearing on whether it can still be an extant species.
Did you see this earlier post: 11 million year old extinct animal alive and well...
Yes, of course. You would incline so...hmmm...I see. But what on God's green earth are you inclining on? Why not incline on the fact that the animal is so remarkably "like a duck" that it probably was a duck - in light of the fact that there is absolutely no reason to believe it wasn't a duck.
I just don't get you guys sometime.
There is nothing that says this can't happen.
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