New Spinosaur Rivals Giant Meat Eaters.

Rubecula

Well I don't actually read the bible, not even sure I own one. However didn't it say in genesis that Cain went to the land of Nod and took a wife?

So what species would this wife be?

Sorry badly made point really.:o


Mutation is a form of evolution that is certain, but there are so many factors to cause mutations. Environmental pressures, survival pressures, and even radiation has an effect.

Note: Nearly all Mutations do not produce an evolutionary step forward, mostly they are dead ends and often die out instantly or within a generation. It is just very occassionally that a mutation becomes a good survival trait and continues. Incest within a species may or may not have some effect on this, especially as Incestual relationships seem to be frowned on by nature itself.

Alvin T. Grey

Am I the only one who has trouble visualizing Spinosaurus working the way it is usually depicted?

The thing that I don't understand is his sail.....
It's rigid.

http://images.wikia.com/fossil/images/0/04/Spinosaurus_Monograph.png

Look, they are extensions of the backbone. For the sail to move, the whole back bone needs to move. Which means that it actually woud work like a sail in water. If Spino moved at a right angle to the current, he gets swept away.

Secondly they are usually pictured on two legs...Every other dino that I know of and has a sail or spines are quadrupeds or mostly quadrupeds.

What gives?

Adam Khor

Alvin T. Grey wrote: »

Am I the only one who has trouble visualizing Spinosaurus working the way it is usually depicted?

The thing that I don't understand is his sail.....
It's rigid.

http://images.wikia.com/fossil/images/0/04/Spinosaurus_Monograph.png

Look, they are extensions of the backbone. For the sail to move, the whole back bone needs to move. Which means that it actually woud work like a sail in water. If Spino moved at a right angle to the current, he gets swept away.

Secondly they are usually pictured on two legs...Every other dino that I know of and has a sail or spines are quadrupeds or mostly quadrupeds.

What gives?

The sail doesn´t HAVE to move; if it was, like I suggested, a dorsal fin like that of a shark, it would have to be rigid to provide stability to the beast when underwater.
As for the two legged part, it's not really like that, there are other dinosaurs with high spines are two legged (Acrocanthosaurus, Suchomimus, Concavenator/Becklespinax etc). Dimetrodon was not a dinosaur, as you know.

Alvin T. Grey

Adam Khor wrote: »

The sail doesn´t HAVE to move; if it was, like I suggested, a dorsal fin like that of a shark, it would have to be rigid to provide stability to the beast when underwater.

But the dorsal fin of a shark is a very small surface area as compared to the body, looks like spino (as depicted) has something massive going on. It looks in some cases to ge equal to the aspect of the body it's supposed to stabelize.

As for the two legged part, it's not really like that, there are other dinosaurs with high spines are two legged (Acrocanthosaurus, Suchomimus, Concavenator/Becklespinax etc). Dimetrodon was not a dinosaur, as you know.

I'm new to this, so I only recognize two of those. I'm talking about dinos like Stegosaurus (sp?) I know they weren't sails, but the point stands. or Dinos like Ouranosaurus. And because its rigid I'd imagine that the act of getting from all fours to two would be difficult due to resistance.....

Kess73

Alvin T. Grey wrote: »

Am I the only one who has trouble visualizing Spinosaurus working the way it is usually depicted?

The thing that I don't understand is his sail.....
It's rigid.

http://images.wikia.com/fossil/images/0/04/Spinosaurus_Monograph.png

Look, they are extensions of the backbone. For the sail to move, the whole back bone needs to move. Which means that it actually woud work like a sail in water. If Spino moved at a right angle to the current, he gets swept away.

Secondly they are usually pictured on two legs...Every other dino that I know of and has a sail or spines are quadrupeds or mostly quadrupeds.

What gives?

The sail does not bother me if the animal was totally submerged. I look at it as potentially acting like how the Keel does on the hull of a sailboat, just upside down.

What bugs me about the picture is that if they want to discuss the idea of a Spino being a capable underwater hunter rather than it simply being a large carnivore that can swim in a somewhat clumsy manner like a modern bear, then it should have obvious webbed feet in the depiction.

It's legs should be webbed similar to how they are with the hind legs of a modern crocodile imho, just like on this Nile crocodile.

Adam Khor

Alvin T. Grey wrote: »

But the dorsal fin of a shark is a very small surface area as compared to the body, looks like spino (as depicted) has something massive going on. It looks in some cases to ge equal to the aspect of the body it's supposed to stabelize.

True, but keep in mind that Spinosaurus is a giant; it would need a much larger "dorsal fin".
The truth is, though, we don´t really know how large the sail was, because no complete Spinosaurus skeleton or sail has ever been found.

Alvin T. Grey wrote: »

I'm new to this, so I only recognize two of those. I'm talking about dinos like Stegosaurus (sp?) I know they weren't sails, but the point stands. or Dinos like Ouranosaurus. And because its rigid I'd imagine that the act of getting from all fours to two would be difficult due to resistance.....

But you really can´t compare Stegosaurus with Spinosaurus; as you said, Spino's spines were part of the vertebrae; Stegosaurus plates, if I'm not mistaken, were only embedded on the skin. They were actually osteoderms like those of modern day crocodiles, only highly modified. They probably didn´t hinder the animal's movements a lot.
As for Ouranosaurus, its spines have a different shape than those of Spinosaurus and are more likely to have supported a camel-like hump. Or that's the last thing I read.

I agree with you Kess; if Spinosaurus was truly a diving/swimming animal its toes may have been webbed; I don´t think there's any evidence against that.

Alvin T. Grey

Funnily enough the more I think about it the more sense it makes....
Can we agree that Spinio had a large set of spines, and that at their highest point they almost doubled the girth of the animal?

If we can agree that then follow me for a second....

If you are driving a 40ft truck and you have a 30mph headwind, you don't have a problem, but if that becomes a 30mph sidewind you do. Thats the reason they close exposed bridges to high vehicles at times.

Now I can think of two ways around that.

First allow the object to bend with the wind, or make it colapsable. - Like the sail of a tuna? Neither is true for Spino.
Or move the centre of gravity very low so that only the strongest currents have that effect. Which on land means quadruped.

Alvin T. Grey

Adam Khor wrote: »

True, but keep in mind that Spinosaurus is a giant; it would need a much larger "dorsal fin".
The truth is, though, we don´t really know how large the sail was, because no complete Spinosaurus skeleton or sail has ever been found.

I realize that, my problem is with it's depiction in popular documents. I suppose it makes it look more 'badass'. As for the size of the sail, the larger the sail as compared to the rest of the animal the worse the problem becomes.

But you really can´t compare Stegosaurus with Spinosaurus; as you said, Spino's spines were part of the vertebrae; Stegosaurus plates, if I'm not mistaken, were only embedded on the skin. They were actually osteoderms like those of modern day crocodiles, only highly modified. They probably didn´t hinder the animal's movements a lot.
As for Ouranosaurus, its spines have a different shape as those of Spinosaurus and are more likely to have supported a camel-like hump. Or that's the last thing I read.

True dat.

Adam Khor

Alvin T. Grey wrote: »

Funnily enough the more I think about it the more sense it makes....
Can we agree that Spinio had a large set of spines, and that at their highest point they almost doubled the girth of the animal?

If we can agree that then follow me for a second....

If you are driving a 40ft truck and you have a 30mph headwind, you don't have a problem, but if that becomes a 30mph sidewind you do. Thats the reason they close exposed bridges to high vehicles at times.

Now I can think of two ways around that.

First allow the object to bend with the wind, or make it colapsable. - Like the sail of a tuna? Neither is true for Spino.
Or move the centre of gravity very low so that only the strongest currents have that effect. Which on land means quadruped.

Well, your not the first one to suggest a quadrupedal stance for spinosaurs, but let's keep in mind one of the animal's main traits; those huge hand claws. They were very sharp, and larger than those of other theropods implying that they were being used as important weapons, perhaps to fight, to aid when hunting or both.
A quadrupedal Spinosaurus would have to walk on a very unusual manner to keep the claws from becoming blunt; it would have to support all of its weight on the sides of the hands, like an anteater or a giant sloth, with the claws facing inwards.
This seems rather impractical IMHO; I don´t think the animal's wrists were adapted for this (although I don´t know for sure; would be interesting to find out), and it would make it a very slow animal too, which would be a disadvantage in a land shared with other giant predators like Carcharodontosaurus and Deltadromeus (both of them agile bipedal runners, particularly the latter).

The fact remains that Spinosaurus had long, strong arms when compared to other theropods, but this could make sense if it was a swimmer; the forelegs would be used actively to swim, like any quadrupedal animal today, making Spinosaurus a better swimmer than other theropods. And this fits the Spinosaurus' obvious adaptations to a water-dependant lifestyle (crocodile-like snout and conical teeth to capture fish).

Kess73

Alvin T. Grey wrote: »

I realize that, my problem is with it's depiction in popular documents. I suppose it makes it look more 'badass'. As for the size of the sail, the larger the sail as compared to the rest of the animal the worse the problem becomes.




True dat.

Another thing is that the sail is assumed to be thin and tall. Who is to say that it was not thick and short? That way it could be a thick yet somewhat streamlined ridge, again acting as an inverted keel when the animal was in water.

Adam Khor

Kess73 wrote: »

Another thing is that the sail is assumed to be thin and tall. Who is to say that it was not thick and short? That way it could be a thick yet somewhat streamlined ridge, again acting as an inverted keel when the animal was in water.

I think the Spinosaurus depicted in Jurassic Park had a thick, short sail, if I remember clearly... and it was depicted as a swimmer/diver at one point.

Kess73

Adam Khor wrote: »

I think the Spinosaurus depicted in Jurassic Park had a thick, short sail, if I remember clearly... and it was depicted as a swimmer/diver at one point.

Here is the JPIII Spino.

Alvin T. Grey

Adam Khor wrote: »

Well, your not the first one to suggest a quadrupedal stance for spinosaurs, but let's keep in mind one of the animal's main traits; those huge hand claws. They were very sharp, and larger than those of other theropods implying that they were being used as important weapons, perhaps to fight, to aid when hunting or both.
A quadrupedal Spinosaurus would have to walk on a very unusual manner to keep the claws from becoming blunt; it would have to support all of its weight on the sides of the hands, like an anteater or a giant sloth, with the claws facing inwards.

I know, and its one of the weak points in my arguement. - The problem is, the rest of it makes bloody sense.

Damn YOU SPINO for being so....weird.

This seems rather impractical IMHO; I don´t think the animal's wrists were adapted for this (although I don´t know for sure; would be interesting to find out), and it would make it a very slow animal too, which would be a disadvantage in a land shared with other giant predators like Carcharodontosaurus and Deltadromeus (both of them agile bipedal runners, particularly the latter).

Reminds me of the old joke about the two cameramen and the lion...it just had to be fast enough.

The fact remains that Spinosaurus had long, strong arms when compared to other theropods, but this could make sense if it was a swimmer; the forelegs would be used actively to swim, like any quadrupedal animal today, making Spinosaurus a better swimmer than other theropods. And this fits the Spinosaurus' obvious adaptations to a water-dependant lifestyle (crocodile-like snout and conical teeth to capture fish).

That makes sense, but a theropods shape just doesn't seem to be the most hydrodynamic, and especially one shaped like this.

BTW thanks for answering the query, it's going to be fun thinking about this.

Yes.
I need a life..:D

Adam Khor

Can´t see the pic...

But here it is:




The sail is quite short for the animal's size. Much smaller than usually depicted in paleoart, but also thicker.
BTW, say what you want about Jurassic Park III but IMHO it has the best CG and animatronics of any movie I have ever seen, period. Most CG these days looks fake.
Just saying...

Alvin T. Grey

Adam Khor wrote: »

I think the Spinosaurus depicted in Jurassic Park had a thick, short sail, if I remember clearly... and it was depicted as a swimmer/diver at one point.

The problem I have with that is
http://images.wikia.com/fossil/images/0/04/Spinosaurus_Monograph.png

If I'm reading it right, the spine is bigger than the associated ribs, so hump or sail, it was comparitivly big...

Adam Khor

Alvin T. Grey wrote: »

The problem I have with that is
http://images.wikia.com/fossil/images/0/04/Spinosaurus_Monograph.png

If I'm reading it right, the spine is bigger than the associated ribs, so hump or sail, it was comparitivly big...

Ehm... that drawing is grossly outdated. Here, have a picture of the actual, original Spinosaurus remains found by Ernst Stromer in Egypt:



As you can see, there are no associated ribs. But yes, the spines are still huge.

Alvin T. Grey

See?
I told you I'd learn something new..
I suppose that one could look at other theropod dinos and from their size estemate what 6 foot of hump/sail would look like.

And we end up with one weird assed dino.

Truth be known (and not to Jack Horner it) I have a feeling that Spino was not as badass as other theropods. Certainly not my beloved T-Rex.

Hence my problem with how it's depicted........

There I confessed.

Galvasean

Adam Khor wrote: »

Ehm... that drawing is grossly outdated. Here, have a picture of the actual, original Spinosaurus remains found by Ernst Stromer in Egypt:



As you can see, there are no associated ribs. But yes, the spines are still huge.

When you see those fossils it is obvious that the JP3 Spino's spines are too small for the size of the animal depicted. They probably wanted it to look sleeker and more deadly. They also gave it curved knife-like teeth. Again, probably for aesthetic reasons.

PS: I also found the CG in JP3 quite patchy in places.

Adam Khor

Galvasean wrote: »

PS: I also found the CG in JP3 quite patchy in places.

Patchy as in...?

I don´t understand why everyone made such a fuzz about Peter Jackson's King Kong, the CG was terrible, especially the dinosaurs.

Galvasean

Adam Khor wrote: »

Patchy as in...?

Patchy as in many of the dinosaurs often did not appear to be bearing weight. they kind of float where they stand.
Plus, what the hell was with those brachiosaurs?


The animatronics are brilliant though:

Adam Khor

Agreed; when it comes to animatronics I think I've never seen something as life-like as the female raptor at the end. Stan Winston was a genius.

Galvasean

Didn't even get an Oscar nimination for SFX. Bit of a shame considering A.I. did.

Adam Khor

The bastards... but still, what did you expect? They gave Titanic the best special effects award in 1997, instead of The Lost World :S

Galvasean

To get back on topic (sorry), the name Oxalaia quilombensis is now official after publication.
http://news.nationalgeographic.com/news/2011/03/pictures/110330-new-dinosaur-crocodile-cousin-brazil/#/new-dinosaurs-brazil-crocodyliform-lizard-life-size_33875_600x450.jpg

Adam Khor

Even more interesting, it seems that there are remains of ANOTHER giant spinosaur in the same fossil site, PLUS remains of a dinosaur similar to Bahariasaurus BUT LARGER, PLUS teeth from raptors! Meaning that raptors and spinosaurs probably DID live together after all!

And, a little bit off topic but, it also seems that tyrannosauroid bite marks were found in the bones of a dinosaur from the time of Deinonychus, suggesting that Deinonychus coexisted with a medium sized tyrannosauroid similar to Xionguanlong, and that the latter possibly got some of its food by scavenging Deinonychus kills! (Since the bite marks of Deinonychus were also found in the bones)

Rubecula

Scenario seems very similar to modern day predator/prey scenarios in Africa and similar.

Possibly Big bruiser comes upon a kill by smaller predators and 'shoos' them away while it enjoys the fruits of their success.

The same theme seems to run throughout life on earth really.

Galvasean

Adam Khor wrote: »

And, a little bit off topic but, it also seems that tyrannosauroid bite marks were found in the bones of a dinosaur from the time of Deinonychus, suggesting that Deinonychus coexisted with a medium sized tyrannosauroid similar to Xionguanlong, and that the latter possibly got some of its food by scavenging Deinonychus kills! (Since the bite marks of Deinonychus were also found in the bones)

OR they worked as a team....

Let me have my dream

Adam Khor

Well... badgers and coyotes, and groupers and moray eels are known to hunt together... maybe not exactly as a team but together nonetheless. Who knows! :>