Welcome Guest [Log In] [Register]






Shoot a firework rocket ~ Winners!
Make a forum zoo!

Welcome to The Round Table. We hope you enjoy your visit.


You're currently viewing our forum as a guest. This means you are limited to certain areas of the board and there are some features you can't use. If you join our community, you'll be able to access member-only sections, and use many member-only features such as customizing your profile, sending personal messages, and voting in polls. Registration is simple, fast, and completely free.


Join our community!


If you're already a member please log in to your account to access all of our features:

Username:   Password:
Add Reply
Favorite Dinosaur Reconstructions
Topic Started: Sep 28 2013, 09:05 PM (305,651 Views)
Stephen
Member Avatar
Stuck on Earth

Yeah, but featherless owls/birds look a lot more like those depictions.

I've seen you compare the reconstruction to mammals; which are much, much less related to dinosaurs than birds and reptiles. Guess what? Those two's faces actually look shrink-wrapped :O The bodies don't look too thin to me, but that might just be me.
Offline Profile Quote Post Goto Top
 
Yi Qi
Member Avatar


Stephen
Feb 14 2015, 08:53 PM
Yeah, but featherless owls/birds look a lot more like those depictions.

I've seen you compare the reconstruction to mammals; which are much, much less related to dinosaurs than birds and reptiles. Guess what? Those two's faces actually look shrink-wrapped :O The bodies don't look too thin to me, but that might just be me.
They may look more similar than the clusterf*** of mammal skull shapes, but in no means they look like a skeleton.

Posted Image
Posted Image
Posted Image
Posted Image

Infact, if we shrinkwrap birds....

Posted Image
Posted Image

they turn out far more horrifying than mammals.
Offline Profile Quote Post Goto Top
 
Stephen
Member Avatar
Stuck on Earth

...

Neither does anything in that reconstruction look like a skull (not talking about the bodies, not an expert there). If you look at that rooster, minus the ornaments, it looks quite skinwrapped.

Comparing those shrinkwrapped birds to the previously mentioned depiction is wrong - the dinosaur one is not nearly as bad. (Plus, featherless swans and shoebills would look pretty similar, albeit with a little more body fat)
Offline Profile Quote Post Goto Top
 
Paleop
Member Avatar
Paleopterix

that poor chicken.......




off topic slightly:
do you guys think a contest where the goal is to present dinosaurs in a way that their skulls are not as clearly indicated as most art of them would be a good idea?
translation: a contest where the shape of the animals head does not quite look like the skull with a thin layer of soft tissue + has added tissue, like hippo skull vs. full head

I hope you can understand that because i can't (x
Offline Profile Quote Post Goto Top
 
Yi Qi
Member Avatar


Stephen
Feb 14 2015, 09:40 PM
...

Neither does anything in that reconstruction look like a skull (not talking about the bodies, not an expert there). If you look at that rooster, minus the ornaments, it looks quite skinwrapped.

Comparing those shrinkwrapped birds to the previously mentioned depiction is wrong - the dinosaur one is not nearly as bad. (Plus, featherless swans and shoebills would look pretty similar, albeit with a little more body fat)
I wasn't in fact criticising the reconstruction but rather the act of shrinkwrapping itself ;)
Offline Profile Quote Post Goto Top
 
Even
No Avatar


About the Spinosaurus, there are other alternatives, such as altering the center of gravity by making the neck erect like a crane's (Joschua Knuppe's and Andrea Cau's idea), or speculating that the adults are aquatic for their whole life
Offline Profile Quote Post Goto Top
 
Yi Qi
Member Avatar


Even
Feb 15 2015, 11:58 AM
About the Spinosaurus, there are other alternatives, such as altering the center of gravity by making the neck erect like a crane's (Joschua Knuppe's and Andrea Cau's idea), or speculating that the adults are aquatic for their whole life
While the first one is possible (like anything at this point really), neck muscles like the ones that are proposed by Cau, which attach on the back are unheard of on any archosaur, or any vertebrate for that matter.

Now, the second one is impossible, mainly due the fact that archosaurs cannot become viviparous, meaning a fully aquatic lifestyle is wholely discarded.

As of now, the quadrupedal gait is the only one which has nothing going against it.
Edited by Yi Qi, Feb 15 2015, 12:58 PM.
Offline Profile Quote Post Goto Top
 
DinoBear
Member Avatar


What is going against it simply having the pelican-style neck posture? Also, would it be all to difficult for it to rear back a bit?

Anyways, to keep this from being completely off-topic, Platecarpus. A little slim, but hey, still looks good.

Posted Image
Edited by DinoBear, Feb 15 2015, 01:17 PM.
Offline Profile Quote Post Goto Top
 
HENDRIX
Member Avatar
-retired-

I simply don't see why archosaurs couldn't be viviparous - we just do not know of any viviparous archosaur. It happened several times in other taxa, so why not there too? Mutations can occur any time, we really cannot tell what Spinosaurus' egg structure looked like, so it's not wise to rule out fully aquatic lifestyle completely, just because we don't know.
It's the same with quadruped gait, we have no theropod that is certainly quadrupedal, so why should Spinosaurus suddenly be? There are indices pointing that way, but it's the odd one out. We simply need more material to solve this debacle.
Online Profile Quote Post Goto Top
 
Iben
Member Avatar
There'll be no foot-walking! Just air-flying!

Austroraptor
Feb 15 2015, 12:57 PM


As of now, the quadrupedal gait is the only one which has nothing going against it.
I honestly have to disagree with that. Saying that there's absolutely nothing against it is a bit blunt, because if there was nothing against it it wouldn't remain such a debate at this point :P It still rests on the idea that the forearms were nothing like other theropods we know so far. This is really where you can go either way, it's completely based upon this. In my personal opinion, it's safer to explore all the options that start with the assumption that the arms/shoulders/wrists were among the lines of what we know today (which can't deal with quadrupedal locomotion as explained by J. Headden ) than to assume this was the opposite. Of course, this is completely up to you really. Though I'm a bit more sceptical when it comes to quadrupedal gait, I wouldn't mind it going either way as both ways give us a truly fascinating animal. If it were a biped, I wouldn't be surprised if it was rather clumsy on land, but that isn't something that unusual for animals that are more specialized towards swimming or even flying (not implying that Spinosaurus could fly, obviously ._. ).

(I also recall something about the centre of gravity not being completely correct, but I can't remember who made blogposts about this, I thought it was Headden but I might be wrong )

Now on topic I like this :

Posted Image

As posted by Holtz on his Facebook today this is one brilliant post. It really shows that arguments against feathers on tyrannosaurids are just total bs. xD
Offline Profile Quote Post Goto Top
 
Yi Qi
Member Avatar


HENDRIX
Feb 15 2015, 01:35 PM
I simply don't see why archosaurs couldn't be viviparous - we just do not know of any viviparous archosaur. It happened several times in other taxa, so why not there too?
Because archosauriforms take calcium from their eggs during their embriologycal development, birds and turtles have been going at the sea for a far longer stretch of time than any dinosaur and yet they've still failed to produce viviparous forms, im no bird specialist or embriologist for that matter, but iirc the hard eggshells are intrinsically linked to their embriological development in a way they just can't get rid of them.

If sea turtles, which have been marine far before any aquatic dinosaurs and were lately discovered to have been at the base of the archosauriform family tree, have failed to produce viviparity when it'd greatly be an advantage for an aquatic animal, qhat makes you think far less aquatic spinosaurus would have developed such impossible (for archosaurs) breeding method?

I agree with the rest of the post tough, this debate will never be settled untill we have this animal's limbs, my only point is that the quadrupedal gait is the most likely of the explanations given thus far, people who go against it tend to either compare spinosaurus to the typical spinosaurid or the typical theropod, and if we know anything for certain, is that it was not typical.

Quote:
 
What is going against it simply having the pelican-style neck posture? Also, would it be all to difficult for it to rear back a bit?


Spinosaurus had a center of gravity on the front of its body, to sustain such posture, it would need, as Cau proposed, ligaments joining the neck and back muscles, a thing unheard of in vertebrates, again, its not impossible, but its far more of a stretch than the probably safer knucklewalker hypothesis.

@Iben: The center of gravity was challanged by Hartman, and then corrected back by the original authors, and again you're assuming it was anything like other theropods, which it most certainly wasn't. True, the creature's arm structure would have to be different than anything we've seen so far on theropods, but again, isn't just everything about it?

im not saying the other hypothesis are wrong or that this is an absolute truth, what i mean is, so far, this is the theory with most street cred amongst the hypothesis that have been fluctuating on the internet

the truth is we never know untill we have the beast's arms, but untill then, this is the hypothesis which lends itself most credibility.

ontopic:

Posted Image

Because Baurusuchus is freaking awesome.
Edited by Yi Qi, Feb 15 2015, 02:26 PM.
Offline Profile Quote Post Goto Top
 
Iben
Member Avatar
There'll be no foot-walking! Just air-flying!

Austroraptor
Feb 15 2015, 01:55 PM

@Iben: The center of gravity was challanged by Hartman, and the corrected back by the original authors, and again you're assuming it was anything like other theropods, which it most certainly wasn't. True, the creature's arm structure would have to be different than anything we've seen so far on theropods, but again, isn't just everything about it?

Actually no, it's not him I'm talking about. It was someone who pointed something out about the position of the neural spines in the reconstruction which didn't follow the generally accepted view, which would switch the centre of gravity to the back. I really have to find it, if I do than I'll post it here.

I kinda have to disagree that it wasn't anything like other theropods. It's one thing to say that it proportionally was different from other theropods, but it's a whole other thing saying it's nothing like it at all. One of the problems here though is that they gave it a more typical build on the arms, and from what we know ( as Headden has pointed out in the link I gave ), it doesn't really allow a natural way of quadrupedallity .

Headden
 
Second, the authors even provide a furcula (recovered with the spinosaur Suchomimus tenerensis) for the shoulder, and this would have kept the shoulders from moving independently of one another, meaning it is unlikely the arms were permitted to walk in anything like a natural gait or a “typical” quadruped.


Basically, what I'm saying, in their current reconstruction they did use pieces from related animals in order to reconstruct the arms/shoulders, and those do not allow the walking proposed by the authors that's something that has been established. It's all based on a bunch of assumptions. I don't see that as more street cred than other theories, but I can understand it does to you.


But we probably should move this to another topic instead of cluttering this one over and over again xD
Edited by Iben, Feb 15 2015, 02:47 PM.
Offline Profile Quote Post Goto Top
 
Yi Qi
Member Avatar


Iben
Feb 15 2015, 02:42 PM
Basically, what I'm saying, in their current reconstruction they did use pieces from related animals in order to reconstruct the arms/shoulders, and those do not allow the walking proposed by the authors that's something that has been established. It's all based on a bunch of assumptions. I don't see that as more street cred than other theories, but I can understand it does to you.


But we probably should move this to another topic instead of cluttering this one over and over again xD
I'm not saying its all good and zany or definitive either, i'm just saying we can't say anything at all so far about the animal's front structure, and while that, this theory is the one that, atleast to me and to Marco Auditore, one of the folks who had acess to the actual bones, made more sense.

and sure, lets end this discussion and put the art on the favorite dinosaur art topic:

tough not a dinosaur...

Posted Image

Ahytherium is a fantastic semi aquatic megalonychid sloth from Brazil, tough unlike more famous aquatic sloths, this was a river dwelling creature and not an ocean dwelling one.
Offline Profile Quote Post Goto Top
 
CyborgIguana
Member Avatar


Wait, you mean Thalassocnus was an OCEAN DWELLER?

Sloths are even weirder than I thought! xD
Offline Profile Quote Post Goto Top
 
Yi Qi
Member Avatar


CyborgIguana
Feb 15 2015, 05:33 PM
Wait, you mean Thalassocnus was an OCEAN DWELLER?

Sloths are even weirder than I thought! xD
By ocean i mean sea, not open ocean obviously xD
Offline Profile Quote Post Goto Top
 
4 users reading this topic (4 Guests and 0 Anonymous)
Go to Next Page
« Previous Topic · Extinct Animals & Evolution · Next Topic »
Add Reply