I am extremely disapointed that no one in this discussion has told others to Walk the Dinosaur.

Quarantine the site before it's too late.

An animal that uses a tail for balance has a tail that is an expansion of the spine. The tail is a mobile extension of its spine in all three fields of movement. Observe a cat, or a lizard, or an Opossum, or a monkey. Anything with a tail. The tail is a vital part of their balance, and is controllable by them. Attaching a "tail" to a chicken, or anything at all, does not simulate a tail. This is inherently a bunk study.

Well said, our knowledge of Dinosaurian tails is extremely limited; however, if we look at modern day birds you could argue that dinosaurs had stiffend tails due to birds performing advanced balancing manoevers wityh a stiffend tail constructed of feathers. This has been applied to argueing the function of the stiffend tails of Dromaeosaurids. this however is invalid. dromaeosaurids such have velociraptor have recently been revealed to have had a greater degree of flexibility than previously thought. While modern day Birds such as the Secretary bird fan their tail feathers providing the swing necessary when balancing.

A secretary bird would be a much better candidate than a chicken if gait is what they're looking to study here. The secretary bird already is evolved for a longer, more rigid tail, whereas a chicken has been bred without that for many centuries. It would take generations of using prosthetics on chics who are then bred, to really see how the chicken would evolve to walk with such a device. Changes were noticed quire early on, but anyone with a prosthetic limb (or tail int his case) has to make changes in gait, that may not necessarily reflect a true gait with a true limb. If humans somehow evolved into uni-ped creatures, and someone down the line was curious how a bi-pedal human walked, attaching a prosthetic, doesn't give a true simulation of that. The chicken will be forced to make changes in how it runs and walks, that don't necessarily mimic the real thing at all, and might be quite uncomfortable, which an animal evolved with a tail is probably less likely to be.

"dromaeosaurids such have velociraptor have recently been revealed to
have had a greater degree of flexibility than previously thought."

Right. Which makes a study like this quite hard to manage. How do you give a chicken a flexible tail?

I was watching a mocking bird outside a minute ago, as it ran around looking for food. It has a longer, stiffened tail of feathers, and you can really see the dinosaur in it. It's amazing.

You are really hitting the nail on the head as to the issues with such studies. I to prefer to appreciate the dinosaur in modern birds like the Secretary Bird, Seriema and Cassowary. Rather then trying to force dinosaurian features on to chickens which will never give a result of conceivable accuracy. Which is why I make annual trips to a local Hawk Conservancy trust where they have a Secretary Bird so that I can watch and appreciate dinosaurs in their modern day form, rather then watch a chicken be forced to be an extinct theropod with an unrealistic tail.

Edit: is your name the scientific name for the Secretary Bird split up Sagittarius (Serpentarius)- Saggit Arius

Good try I guess, and I'm sure we can gain insight from this, but this is a chicken walking with a weight attached to it's butt.

maybe if we put weighted prosthetic tail to a group of chicks and let natural selection(with some human intervention) do it's job, after a few hundred generations will we get them walking very alike their dinosaur ancestors? the hypothesis is that they will evolve to suit the prosthetic tail better.

Unnecessary. If we wish we can (with some effort) activate genes already present to get a dinochicken with teeth and tail to observe. Google "dinochicken" if curious

It would be unnecessary at the moment as we have only been able to add just over 3 vertebrae to a chicken embryo's tail. While genetic modification laws prevent such an animal being allowed to hatch.

They do hatch... iv seen some monster chickens!... but they are then gassed, frozen or macerated :o

I believe cedrick was referring to Jack Horner's chickenosaurus

http://1.bp.blogspot.com/-W...

For anyone interested, here is a link to a functional video

http://www.youtube.com/watc...

Thank you!

Very interesting. Who can't help but like this article because who doesn't love dinosaurs?

and chickens! I have a pet ducks. I swear they are mini voliceraptors

The article
http://www.plosone.org/arti...

The video

http://www.youtube.com/watc...

Okay this experiment could use a few improvements,

1) it requires repeated run through of the movement and a direct comparison of the two different movements by playing them at the same time.

2) this needs to be tested on multiple birds to see if the same method of movement is adopted and the progression of the movement should also be documented by recording how they move once per day as the chicks get better/ more used to using their stiffened tails

3) this cannot be used to depict accurately non-avian therapod dinosaur movement due to lacking dinosaurian arms.

4) this test should be performed on additional species but without the removal of the feathers on the legs due to the birds not being chickens and as a result not abusable in the same way that a chicken and a lab rat can be tested on.

Personal notes, after a frame by frame analysis and comparing the frames. Their appears to be a minor increase in stride length with the tail, an increase in swaying from side to side during movement due to reduced balance control and there is also an increase in the forward movement of the head bob with the tail.

Their also appears to be an alteration in the orientation of the femur which is quite neat.

I realize that this kind of anecdotal talk is completely irrelevant when it comes down to the science, but as someone who animates dinosaurs for a living I could see a clear difference.

The instant I saw it I thought "that's a dinosaur!", and I was completely mesmerized by it XD

Obviously, this can't be used as frame by frame reference for any particular theropod, especially not the larger ones. the stride characteristics of between species of mammals and birds can differ quite a bit.
However, I would think it's very good evidence for dinosaurs having a femur driven stride.

Watching the video example =/= reading the paper.

Re suggestion 1: "In both conditions, each subject was recorded four times. The mean of each subject was used for statistical analysis."

Re suggestion 2: "Twelve domestic chickens (Gallus gallus) were reared from two
days after hatching (body mass of 43.0±2.8 g) until they reached sexual
maturity (ca. 12 weeks; body mass of 725±51 g), and maintained with food
and water ad libitum. Subjects were divided into three groups
of four subjects each: a control (C), a control-weight (CW) and an
experimental (E) group. All birds were of the same age, and there were
no differences in final weight between groups."

Re: suggestion 3: Reading the discussion will give you further insight.

Re: comment 4: they reported the femur observation you are claiming as your own. Also, you mean to say, "there also..."

the supplemental video is not meant to represent their only data point and only means of analysis.

Those observations where made prior to finding the paper as it was not linked on the IFL science and I was at school where the proxy system blocks links to journal articles so I had to try and work out the difference for myself, as a result I had to wait till I got home to track down the paper.

1) The experiment could have been repeated as the chicken aged as the overall movement may have undergone additional/ different changes as the chicken ages and develops a differing centre of mass and size ratio.

2) Point taken although a larger test group could have been used for each to improve reliability, however the experiment is still inaccurate.

3)The huge variation of theropod arms especially in maniraptorans makes it difficult to simulate the full range and effect on the body posture. Meaning we can never attempt to map and predict the movement of any individual species of Therapod. However this could be giving us a better idea as to how the group moved as a whole however it may just mislead us.

4) I didn't claim it was a unique observation all I did was made that post prior to finding and posting the article as a later link. Also pointing out a grammatical error does not increase the validity of a statement. Unless it is a Debate about the English language not mechanics of motion in extinct theropod dinosaurs.

Pretty sad that a school would block journals, haha. Almost seems contradictory to the purpose of a school.

It's more the articles that link to the journals are blocked we can use JSTOR etc however in order to track down the article itself I had to use my home browser.

plus... they need a method to simulate small arm :)

The truth is we can never replicate a truly accurate representation of the movement of dinosaurs. However trying to test just for leg posture due to the tail could lead us in the wrong direction. As a chicken lacks the full range of muscle attachments In the tail and the caudofemoralis may have had a greater importance in terms of posture then the article makes it out to be. Also the majority of non avian theropod dinosaur either have teeth or a more heavily built beak. Changing the mass of the head. So the centre of gravity would have been different from that of the chicken experiment. Perhaps a combination of the weight on the back and the tail could have been used. Although I doubt this would have had a large effect.or increase the accuracy of the result.

I salute you sir, in recognition of both your interest in and implementation of true science

That YouTube vid sure was terminated quickly.

Those damn whiney moralfags hey.

Crippling baby chickens doesn't seem very nice though..

They are simply being raised in a different fashion. Doesn't seem like it's crippled either, dinosaurs weren't crippled, why would the birds be.

It doesn't cripple the bird, it turns it into a tasty Tyrannosaur. What's not to love?

Neither does injecting mice with cancer drugs. Why is it that it's okay to hurt smaller animals, but after they get about as big as a rabbit, we're all sorts of upset about it?

Personally I don't see any difference in terms of morality between a tiny mammal and a medium-sized avian. The mouse is far more intelligent... and we have to experiment on SOMETHING to understand how things work.

Jeff you are also right in saying that mice are very intelligent and some of the experiments are quite cruel. Now here is what I say to that and you can shoot me down for it because I hate myself whenever I say this, but remember their is no ideal world. I am fine with farming and testing on animal species( as long as some of the studies are used to aid their wild counterparts rather then pure human research) as long as they are non wild species produced by human selection. This is only if the importance of the farmed animals wealth fair does not go above those of wild animals. This is one of the reasons why I hated the UK's Badger Cull. It was considering the needs of a domestic species over that of an important animal within ecosystem.

Jeff there are some animals which can be legally tested on and some that can't it just so happens that the biological representative for such studies on birds is a chicken due to it being a largely domestic species. Now after reading the article I can conclude that no major harm was done. Although I am not an expert in signs of avian stress, or was I present in observing the birds.

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