1/40 Stegosaurus ungulatus- Released

[Blade-of-the-Moon]

Interesting choice of Stegosaurus species How about a browsing pose, with some ferns or shrubs on the base?

I wonder if it is a valid species?

"...Maidment et al. (2008) reviewed the known Stegosaurus material and concluded that all of the differences between specimens could be accounted for by intraspecific variation. All specimens previously described as Stegosaurus were therefore either referred to Stegosaurus armatus or considered to be indeterminate..." (Maidment 2010)

If it is a S. armatus, I wonder if the number of plates on the back are still correct?

I am not sure myself. I based it on Gregory Paul's reconstruction in his Princeton Field Guide. Well whatever, this one is finished sculpting, and I think it turned out real nice, will post photos of the finished clay sculpt when I can do so.

Great ! If you get it casted up before shipping my items I might just tack it on to the current order.

[dinonikes]

Finished clay sculpt-

[mmfrankford]

Very nice! 

[Blade-of-the-Moon]

Well..I'm sold. Just tell me how much..lol 

Are you casting it soon ? Might add it to my current order.

[Balaur]

That's one pretty Stegosaurs. 

[Jetoar]

Good work as always  .

[wings]

It's a nice sculpture unfortunately it has the wrong hand shape. This was mentioned quite early by Patrx (http://blogs.smithsonianmag.com/dinosaur/2010/11/stegosaurs-walked-like-sauropods/) and you can get the actual paper from (http://www.app.pan.pl/archive/published/app55/app20091105.pdf). The hand very much forms an "U" shape where the palm bones (metacarpals) don't really spread out and don't have much of palm pad.

On top of that the tail spikes maybe angling a little high (perhaps similar to this http://www.statesymbolsusa.org/IMAGES/Colorado/StegosaurusTailweb.jpg, notice the articulation surface on the spikes to the tail doesn't allow these spikes to angle to far up. Here are more examples, like this one http://www.handsontheland.org/garden-park/data/images/SmallStego/Findings/tailpic.jpg or  this one http://scienceblogs.com/tetrapodzoology/wp-content/blogs.dir/471/files/2012/05/i-fdc2e07b792f784321921f82c1d0d1de-Stegosaurus-vs-Hesperosaurus-Carpenter-2010-Dec-2010.jpg, not sure why Paul changed his mind in the guide). Also, it is just more effective for these spikes to face more to the side than angling too far up since the tail is likely to be moving side to side rather than up and down. These spikes probably do angled slightly up (from articulated specimens) but probably not as high as what you have on your creation.

[dinonikes]

I was following Paul's reconstructions when I did this piece, I like the look of his stegosaurs. I based the feet of this model on his drawings, but I like the 'sauropod feet' argument, and changed my model to follow this idea. I think my model has spikes within the range of angle that Paul's stegosaurus reconstructions have, and will just leave it alone. I have a feeling that no one really knows the spikes exact formation for sure, and each seems to have their own theories when looking at the bone articulation. I know Paul wrote that he thinks that the spikes "probably diverged from one another like a pin cusion, making an effective weapon", so I guess it is for each to decide for themelves which configuration is a more effective weapon. I tend to agree with Paul that the 'pin cusion' formation would be most effective, as probably most of the predators that a stegosaurus would be using his tail against would be comingin to attack from above the tail spikes level.

I find it interesting to have watched how many times since the late 80's/early 90's the thinking regarding stegosaurs has changed and been revised, especially plate numbers and placements, and tail spike numbers and formation. They keep stating they know this or that, then years later they say no this or that is true instead.

[Blade-of-the-Moon]

I was following Paul's reconstructions when I did this piece, I like the look of his stegosaurs. I based the feet of this model on his drawings, but I like the 'sauropod feet' argument, and changed my model to follow this idea. I think my model has spikes within the range of angle that Paul's stegosaurus reconstructions have, and will just leave it alone. I have a feeling that no one really knows the spikes exact formation for sure, and each seems to have their own theories when looking at the bone articulation. I know Paul wrote that he thinks that the spikes "probably diverged from one another like a pin cusion, making an effective weapon", so I guess it is for each to decide for themelves which configuration is a more effective weapon. I tend to agree with Paul that the 'pin cusion' formation would be most effective, as probably most of the predators that a stegosaurus would be using his tail against would be comingin to attack from above the tail spikes level.

I find it interesting to have watched how many times since the late 80's/early 90's the thinking regarding stegosaurs has changed and been revised, especially plate numbers and placements, and tail spike numbers and formation. They keep stating they know this or that, then years later they say no this or that is true instead.

True enough. All you can really go by is the fossils in the end. I've been using some of Paul's pieces to build my Kentrosaurus, but some of the plates and spines don't always look like they should to me..so I change them..within reason. Anything past the fossil bones is open to interpretation anyway we see fit I think.

When do you think this one will be cast bud ?

[wings]

...I think my model has spikes within the range of angle that Paul's stegosaurus reconstructions have, and will just leave it alone. I have a feeling that no one really knows the spikes exact formation for sure, and each seems to have their own theories when looking at the bone articulation. I know Paul wrote that he thinks that the spikes "probably diverged from one another like a pin cusion, making an effective weapon", so I guess it is for each to decide for themelves which configuration is a more effective weapon. I tend to agree with Paul that the 'pin cusion' formation would be most effective, as probably most of the predators that a stegosaurus would be using his tail against would be comingin to attack from above the tail spikes level...

That is the problem with side (lateral) view. As you can see from this diagram (see below) which is also by Paul.



These spikes are angled out similar to the link that I sent earlier (http://www.statesymbolsusa.org/IMAGES/Colorado/StegosaurusTailweb.jpg) and not too different to Carpenter's research (both set in low angles). These tail spikes are drawn in front/back (anterior/posterior) view and they are positioned more laterally (the front pair) or more posteriorly (the end pair) than what you currently have right now. Of course if you are looking on its side, they might look very similar but once you view them from the back as well then you will truly see the extent of these structures. The illusion was created due to the assumption of these spikes are being shorter than their "actual" length.

As to the way the tail striking the predator, Stegosaurus seems to have a similar configuration as in Kentrosaurus (fairly tall spines on the tail vertebrae), which would imply that vertical tail motion is limited (http://scienceblogs.com/tetrapodzoology/2011/01/05/heinrichs-digital-kentrosaurus/, ...the tail could still be bent dorsally to form a gently curved 'U'. Lateral movement was far more extensive...). Could they have raise their back end first (as in raising their tail first) before swinging their tails from side to side (so that these spikes don't necessarily have to angled so far up) rather than swinging them in an upward angle? I don't know but it's possible.

In regards to the hands, I think Paul has a similar idea in his reconstruction. The following paragraph is from one of his articles back in the 80s' (please see below, http://gspauldino.com/Howto.pdf).

"...It is important to remember that no archosaur had hands that looked like the feet. Due partly to different bone structures their fore feet always lack a heavy central pad and are hollow behind, giving them a distinctive half-moon shape. In hadrosaurs, iguanodonts, sauropods, and stegosaurs the fingers are united into a psuedohoof in that they are encased in a single lunate pad, with most or all of the single hooves lost..."

Also from looking at his muscle study diagram for the stegosaurus (in the field guide), I think it is clear that the left manus (hand) lacks the palm pad and the "palm bones (metacarpals)" area united in a similar fashion to the sauropods (as indicated by the darker shading behind the first finger where concavity changed on its palm). For whatever reason, Paul never have a study on this topic, maybe he thinks it looks obvious or perhaps he doesn't think it is interesting enough to develop into a paper (just guessing). So all he did is to give a brief account and reenforced this idea in his illustrations.

[dinonikes]

If one looks at the skeletal reconstructions of Stegosaurus stenops and Stegosaurus ungululats in Paul's Field Guide book, you see he shows a side view of both of these, and a top view of stenops. My model has its tail spikes right on the money both in top view and side view of Paul's reconstructions, so I feel that my model is within an accurate range if one follows Paul's thinking.

To answer Blade's question about when this will be cast- I already have two orders for this model just based on these photos of the finished sculpt, so it will be cast asap- this one is molded now so it wont be too long.

[Blade-of-the-Moon]

If one looks at the skeletal reconstructions of Stegosaurus stenops and Stegosaurus ungululats in Paul's Field Guide book, you see he shows a side view of both of these, and a top view of stenops. My model has its tail spikes right on the money both in top view and side view of Paul's reconstructions, so I feel that my model is within an accurate range if one follows Paul's thinking.

To answer Blade's question about when this will be cast- I already have two orders for this model just based on these photos of the finished sculpt, so it will be cast asap- this one is molded now so it wont be too long.

Cool. I definitely one as well Malcolm. Just tack it on to my current order and let me know how much via PM , FB, or email.

[wings]

If one looks at the skeletal reconstructions of Stegosaurus stenops and Stegosaurus ungululats in Paul's Field Guide book, you see he shows a side view of both of these, and a top view of stenops. My model has its tail spikes right on the money both in top view and side view of Paul's reconstructions, so I feel that my model is within an accurate range if one follows Paul's thinking.

The last link that I sent was done by Paul and these were based on the very same top and side view of the tail. Here is a simplified version of the diagram (the spikes are rotated so you can see how they line up);



which demonstrates that such side view would also be achieved by "low angled" spikes which I think was what Paul intended to do since these are his drawings also. Anyway, if you don't see it then it'll be hard to explain since it's obvious on these diagrams. In addition to the diagram Paul (1996) wrote:

"...Most restorations show the tail spikes simply sticking straight up on the end of the tail, but this is wrong. In Stegosaurus end of the tail is S-curved so that the last pair of spikes point almost horizontal and straight backwards. The larger front pair of spikes point more to the sides, and nearly horizontally. The spikes therefore diverge from each other like a pin cushion, making an effective weapon..."

[Blade-of-the-Moon]

Not being an expert in the least but looking at the diagrams and Malcolm's model I believe I see what you mean, but it would be a very slight modification and as Malcolm said his interpretation isn't entirely impossible. So I think he's good. Maybe he can try to match what you propose in his next stegosaur .

[wings]

Not being an expert in the least but looking at the diagrams and Malcolm's model I believe I see what you mean, but it would be a very slight modification and as Malcolm said his interpretation isn't entirely impossible. So I think he's good. Maybe he can try to match what you propose in his next stegosaur .

It is certainly not my own idea to have these spikes lower, I was basing my judgement on Paul's comment and his illustration (previous comment), and merely trying to improve its accuracy to Paul's (since that is what Malcolm is based his creation on). Please see Paul's comment from my last post (you might not have seen it because I've just updated it, I didn't have the reference before while I was commenting). It is a nice sculpture but accuracy wise (I'm referring to Paul's drawing) I just can't say it is right on the money (dinonikes wrote ...My model has its tail spikes right on the money both in top view and side view of Paul's reconstructions, so I feel that my model is within an accurate range if one follows Paul's thinking...)

[Blade-of-the-Moon]

Does the skeleton in Paul's new field guide match up with it's tail in this position though ?  I noticed he made those comments in 1996 right ? If it differs perhaps his thinking had changed a bit.

Note I don't have the guide myself yet much to my chagrin.

[wings]

Does the skeleton in Paul's new field guide match up with it's tail in this position though ?  I noticed he made those comments in 1996 right ? If it differs perhaps his thinking had changed a bit.

Note I don't have the guide myself yet much to my chagrin.

There you go (http://img208.imageshack.us/img208/2522/stegosaurustails.jpg), you can see that the 1996 version (separate tails) aren't that much of a different to the one found in the field guide (http://press.princeton.edu/blog/2010/10/01/pgs-daily-dinosaur-stegosaurus-stenops/). Please note that there is no top view for "S. ungulatus" in the field guide, only side view. The spikes are angled up very similar to the other Stegosaurus species(?) so there really is no point for me to scan it and upload it here for you (as all we are going to see is its lateral view).

[Blade-of-the-Moon]

Doesn't look much different from one to the other your right.  I suppose not having an upper view could have been a problem for Malcolm when making his. I run into similar issues myself quite often.  I'd say he's about 99.9 percent spot then..assuming the spikes couldn't move at all.  Malcolm has more accuracy than I've seen in just any other Stegosaurus before..and a hint of the artistic still makes it very desirable to me.

[wings]

Doesn't look much different from one to the other your right.  I suppose not having an upper view could have been a problem for Malcolm when making his. I run into similar issues myself quite often.  I'd say he's about 99.9 percent spot then..assuming the spikes couldn't move at all.  Malcolm has more accuracy than I've seen in just any other Stegosaurus before..and a hint of the artistic still makes it very desirable to me.

My post was never about making changes to the current model but just to be aware of the issues (maybe taking a second look at it) and to make possible adjustment of these elements on the next creation. Yeah, wouldn't it be great if we can get all the different view of the animal, it is rather unfortunate, perhaps some times we'll need to look up the actual specimen and make educational guesses to see how it all fits together.

"...assuming the spikes couldn't move at all...", are you talking mobility on these spikes? I think it is quite a safe assumption, since these spikes have quite rugose articulation surfaces (http://paleobiol.geoscienceworld.org/content/31/2/291/F4.large.jpg), there really isn't much room to move around and it probably lacks this kind of muscle control in the tail end to do so (the vertebrae at the end of the tail doesn't seem to have any specialization for anchoring such muscles http://upload.wikimedia.org/wikipedia/commons/1/15/Stegosaurus_tail.JPG). Most importantly, if the tail is used as a swinging weapon then having mobile spikes might not be such a great idea as these "joints" would provide a weak point for damages.

[Blade-of-the-Moon]

These threads used to be about that..helping Malcolm out when he needed it, but they don't get near the attention they used to unfortunately. If you can catch something early I'd guarantee Malcolm would look into fixing it...like with the front feet.  Heck I didn't know that really..it's something I will have to apply to my Kentrosaurus. 

It is a shame really. I was recently talking to Scott Hartman on DA about lacking all the proper perspectives and what would be the best way to get all views into one piece..the answer to me is a 3D model of the skeleton which can be manipulated and printed from he agreed but it would be a bit down the road.

Yeah I was thinking if they could move at all where they connect then it might make some differences acceptable.  What you say makes sense though. I did recall it was assumed at one point the plates could move or flex hence my thinking there.