Barbarian
Member
You are confusing Sinosauropteryx with the feathers found in amber. One has nothing to do with the other.
We see proto-feathers on Sinosauropteryx. And now we have some proto-feathers from the same period in amber. No bird has been known to have proto-feathers; true feathers appeared first on dinosaurs.
The so-called feathered Sinosauropteryx:
The structures are not modern feathers, say the roughly half-dozen Western paleontologists who have seen the specimens.
http://www.sciencemag.org/content/278/5341/1229.2.short
Yep. That's why they call them "proto-feathers." Later dinosaurs had true feathers. Proto-feathers are just transitional to more developed ones. That's what scientists are telling you. There's even some evidence for melanosomes such as found in feathers.
In fact, there is some evidence now that Sinosauropteryx and/or it's relatives had more evolved feathers in addition to proto-feathers:
The article touched on the fact that its feathers were reported as stage 1 (simple, unbranched filaments, often referred to as "protofeathers") in the parlance of feather development researcher Richard Prum. In the comments, Heinrich Mallison pointed out that they *look* like stage 1, but as Foth showed, crushed feathers (even those of modern birds) often look much more primitive than they are due to taphonomic effects...Currie & Chen 2001 (which as far as I know is the only non-BAND paper to examine the S. prima integument in detail and actually publish their findings) concluded that "The mixture of thick and thin strands close to the body, the increased presence of thinner strands distally, the fact that the thicker strands are positioned close to the body and are normally oriented at higher angles from the body than more distal strands (Fig. 12g), the presence of areas where many of the finer strands lie adjacent and parallel to each other (even kinking together in a few places), and the tendency of finer filaments to angle away on both sides from thicker structures (Fig. 13a) all suggest a feather-like structure with central shafts and plumulaceous barbs."
http://dinogoss.blogspot.com/2012/08/did-sinosauropteryx-have-protofeathers.html
Barbarian observes:
The protofeathers may look very hair-like, but the researchers confirmed they were feathers by looking at them under a microscope, Wolfe said. Hair, found on mammals, has microscopic scales. Feathers, found in birds and dinosaurs, have features called nodes and internodes instead.
http://www.cbc.ca/news/canada/edmont...-feathers.html
They will eventually be able to do a biochemical analysis of them. Want to make a little side bet on whether they turn out to be more like modern feathers than they are like hair?
You would lose that bet since they have already determined Sinosauropteryx did not have modern feathers.
But I notice you aren't going to take the bet. In fact, I'm pretty sure you already have figured out that these protofeathers, found on several species of dinosaur, will have proteins consistent with feathers, but not with hair.
The article you linked to was about feathers found in amber and had nothing to do with Sinosauropteryx.
Which is like saying a feather you found in the grass has nothing to do with a bird.
Then again MBS didn't cite any source for his feathered dinosaur, so I just linked to Sinosauropteryx to show how science can correct errors. However, there were some red flags in the article you linked to: "Feathers believed to be from dinosaurs have been found beautifully preserved in Alberta amber.
The primitive, hair-like feathers known as protofeathers likely belonged to theropods"
Theropods are a type of dinosaur, one group of which, gave rise to birds. I thought you knew.
There were some comments about the feathers found in amber in the Scientific journal:
McKellar et al. (Reports, 16 September 2011, p. 1619) analyzed Late Cretaceous amber specimens from Canada and identified some filaments as dinosaurian protofeathers. We argue that their analysis and data do not provide sufficient evidence to conclude that such filaments are feather-like structures. Further investigation, including destructive sampling, must be carried out for more convincing conclusions.
http://www.sciencemag.org/content/33...796.2.abstract
So, why not take the bet?
unequivocal assignment to either birds or dinosaurs remains impossible, as we stated originally.
http://www.sciencemag.org/content/335/6070/796.3.short
I'm just willing to bet these protofeathers (not found on any known bird) will come out to be chemically more like feathers than like hair. You seem to be a bit unsure of your position.
Barbarian asks:
And have you found out which lungs those are, that your source thinks couldn't possibly have evolved?
I think Async posted this before, but here's a link:
http://m.harunyahya.com/tr/NetCevap/...utes-Evolution
Oh, the Islamic site. I thought so. Few creationists are still willing to do this story:
In birds however, air is unidirectional. New air comes in one end, and the used air goes at the other end. Thanks to special air sacs all along the passages between them, air always flows in one direction through the avian lung. In this way, birds are able to take in air nonstop. This satisfies birds" high energy requirements.
Yaha is something of a crank. (he's an interior decorator by education) Here, he just shows complete ignorance of functional vertebrate anatomy. You see, you also have a unidirectional system. It's called "collateral ventilation" and can save your life in the case of bronchial obstruction. The alveoli communicate with each other through the Pores of Kohn, by way of the Canals of Lambert:
They function as a means of collateral ventilation; that is, if the lung is partially deflated, ventilation can occur to some extent through these pores. They equalize the pressure in adjacent alveoli and thus play important role in prevention of collapse of lung.
http://en.wikipedia.org/wiki/Pores_of_Kohn
In some theropod dinosaurs, this became the dominant form of respiration, and
of course, it was passed on to birds.
A recent analysis showing the presence of a very bird-like pulmonary, or lung, system in predatory dinosaurs provides more evidence of an evolutionary link between dinosaurs and birds.
http://people.eku.edu/ritchisong/birdrespiration.html
So why don't birds have some trace of the bidirectional system? They do. Birds have a collateral bidirectional flow through the neopulmonic bronchi.
Lacking an effective diaphragm as in mammals, this was a way to increase passage of air, necessary for the high metabolic rate of most theropods. And it served the birds as well. As you see, the shift from one form of ventilation to the other could happen rather gradually.
So, you see, there's no problem of how the system went from one to the other. It was scaffolded by combining both systems (which both we and birds have) accompanied by the increasing role of one, and a decreasing role for the other. But the evidence of a previous mode is still there in birds.