Should Acrocanthosaurus be considered an early Spinosaur?

No, it shouldn't. It has slashing teeth, claws, and shorter arms. It had a fairly long snout, but it was also tall, spinosaurus have long thin and short. Acro was just not suited to be a spinosaur, and Spinosaurus was at the same time as Acrocanthosaurus.

I don't think it is. It has the body, arms, neck, skull and teeth of a carcharodontosaur. You could argue that it's a coincidence but what the really defining carachteristic is is the inner ear structure. That's what makes it a carcharodontosaur. Also, instead of having the sails that spinosaurs had, it most likely had a muscular ridge on its back. Unlike spinosaurs, it had places for ligaments to attach so the ridge theory is very probable. I don't think it was an early spinosaur just because it had enlongated vertebrae.

I feel it could be a "middle ground." It had the head, body, and arms of an allosaurian/carcharodontosaur dinosaur, but the sail of a spinosaur. It's arms and claws were a little more robust like a spinosaur too. Allosaurian dinosaurs had long arms and claws, but Acro's were kind of like an in-between with the two groups. It was said that the spinosaurs descended from creatures like the megalosaurs. The megalosaurs were pretty similar to the allosaurian dinosaurs. I think it's possible. Acro started changing slightly with a new sail and stronger arms/claws, but retained the allosaurian head and teeth. Allosaurian Dinosaur(Giganotosaurus) [img]http://j.static-locatetv.com/images/content/4/45795_walking_with_dinosaurs.jpg[/img] Acrocanthosaurus [img]http://fc01.deviantart.net/fs71/i/2011/316/8/d/acrocanthosaurus_by_arneumann-d4g04pz.png[/img] Suchomimus [img]http://images5.fanpop.com/image/photos/28300000/Suchomimus-dinosaurs-28340090-431-236.jpg[/img] That's just my opinion. It's not a fact, but it's a possibility.

All of your points are valid except for the sail which you say matches that of a spinosaur, however if study the fossils carefully even the sail is different between acro and spino.

Spinosaurous: Long strong arms, used for gripping prey (onctiprisits) underwater. Has similer motion sceners on it's nose like a crocidile. A large fragile fan. Narrow nostrils high up on head. Large sturdy legs. Chronicle and straight teeth on top and bottom. Acro: Short strong arms. Chronicle teeth (top) straight (bottom) Small thin fan across back. Huge sturdy legs, good for strength but not for running. Short muzzle (unlike Spino, more like T-Rex) I can see your point but when you compare basic facts (which obviously I had to do) you notice more differences than similer features. Even the fans are different. I can see how they could be related, but their behavors and features are large in difference.

I know there are a fair amount of differences, but there are enough similarities that may justify a reexamination of Acro's exact placement. I think it's somewhere between the allosaurian dinosaurs and the spinosaurian ones. Not really fitting in either. Just a thought though.

I think it was completly allosaurian. It wasn't suited to be a spinosaur, wrong jaws, wrong claws, wrong body.

No, completely different animal.

Besides, I don't even believe in evolution, there's no evidence. It is just a theory that people say is real because they want to believe something. 

Also, most real scientists are (finally) beginning to see the major flaws in it.

 I mean, seriously, my great-great-great grandfather wasn't a monkey or a bigfoot.

No, I would not consider Acro to be a Spinosaur ancestor.  Spinosaurs were already living in a different part of the world, and as far as we know, no Spinosaur ever lived in North America.

The ridge that Acro had was analogous with other Spinosaurs (ex. Suchomimus) and Ouranosaurus.  Even though they may have had the same structure and function, they have two different lineages.

Also, the jaws and arms of Acro were homologous with other allosaurids (and to an extent the carcharodontosaurids).  It just so happened that the population of allosaurs that evolved into Acros had the alleles for more muscular arms and taller vertebrae and they stayed in North America while the other allosaur populations migrated to the landmass that would split into Africa and South America and grew larger and heavier.

@JEZZA

yup, my thoughts as well. Evolution is laughable to me, ive looked over it time and and time again, there are simply too many holes in the theory and everything is simply to orderly and efficient to have come by chance. i could litterally write pages upon pages about the flaws in the theory of evolution(as well as evidence to support creation and clear up missconceptions about it) and there are hundreds of examples of things in nature that completely show evolution to be flase. that however, can be discussed in some other post.

in any case, even if did belive in that nonsennse i still wouldn't thin acaro was a spino ancester,didn't it live around the same time? also the structure of the spines in acaro and in spino are totally different. acarocanthosaurus spines would have supported lots of muscle, were thickly built, and designed to lock into place when needed. none of this applies to spinosaurus spines. plus the overall build and the jaws especially are very different.

I'm gonna propose my position on the subject, but I know that the only response I am going to get is "yoo r rong!!!1 that iss just an oppinion!", so I am going to go with the nonsensical and BS nature of this entire forum and say that this is only based on personal feeling, and that we have no actual fossil evidence to support my position (this is sarcasm, BTW).

Acrocanthosaurus was definitely NOT a spinosaur... Much of its morphology in fact points to it belonging to allosauria and in-turn carcharodontosauria. And enlarged spinal column does not mean shit!

I see it as an Allosaur myself. There were no Spinosaurs in North America, and hardly any at all in the Northern Hemisphere. It's kinda like the lack of Tyrannosaurs in the Southern hemisphere, but Tyrannotitan looks semi-Tyrannosaur with its little arms.

 

Zilla, there's no need to be a di*k just because we have different thoughts than you. 

why do you have to troll us, godzillasaurus? going through old topics just to start a fight again? really? why don't you just go back to the godzilla forums where you belong. 

Oh and P.S., he stated that was HIS personal belief. Unlcuck you, who never does any of that.  you just can't leave damn well enough alone, can you?

Quote: why don't you just go back to the godzilla forums where you belong.

How childish... You don't just go around claiming that somebody belongs on one forum but not another when the two aren't even related in any way. You have no logic; was that supposed to be an insult or something? Because this is by far the worst dinosaur forum that I have ever stepped into.

Quote: Oh and P.S., he stated that was HIS personal belief. Unlcuck you, who never does any of that.

That is because you guys are wrong; having fossil evidence of something is not a damn opinion. Let me rehash this once again: ACROCANTHOSAURUS WAS A NORTH AMERICAN THEROPOD- FACT, ACROCANTHOSAURUS HUNTED SAUROPODS- THEORY, ACROCANTHOSAURUS WAS THE BEST DINOSAUR EVER- OPINION. How many times must I tell you guys that!? You guys never learn!

of course Acrocanthosaurus was a north american theropod? i was talking about your hating on jezza. Do you seriously think i dont know about acrocanthosaurus? What logic do you show us? none. Cuz your just a goddamn troll who has nothing better to do then say" Spinosaurus was bigger" all the time.

I tend to get 'childish' when i've had enough of someone.

Show me YOUR proof for YOUR claims, then i'll take you seriously. i can show you at least one scientific article for my claims, the ones i say are fact. the ones i  just state because  they are MY THEORY, well, we can debate those all day. 

Quote: Cuz your just a goddamn troll who has nothing better to do then say" Spinosaurus was bigger" all the time.

??? How is that being a troll? You are acting like a child! If I read something countless times in many sources, that does not make me a troll

Quote: Show me YOUR proof for YOUR claims, then i'll take you seriously. i can show you at least one scientific article for my claims, the ones i say are fact. the ones i just state because they are MY THEORY, well, we can debate those all day.

Uh, no. I don't have to do that... It is more widely accepted that spinosaurus was larger than tyrannosaurus; I have read that countless times in various sources. Can you provide me your source?

@godzillasaurus

if you truly are the logical person you claim to be, then pherhaps you should consider presenting your argument a bit more politely, of course people are going to get mad at you and argue when you present your information in an insulting fashion. its the same reason that Kyero never got many followers. belive me, choosing your words carefully can save you a whole lot of trouble and allow you to avoid silly little arguments like this one.

in the end, the points you present are ussually excellent, but people won't take you seriously when you insult them, just sayin.

@ Godzilla Himself

Thank you for backing me up. I agree, there is too much detail in the earth, animals, plants, and universe to say it all didn't have a Magnificent Creator.

The Earth was placed at exactly the right position, if it was tilted in any other direction, it would radically change the planet. It would become uninhabittable and life would be gone.

The planet is at directly the right distance from the sun, any closer we'd burn, any further we'd freeze. I don't think some big explosion put everything in directly the right position to sustain life.

And as for the little detail in every animal, such as Acro's spine, bombardier beetle's defense, and all the other amazing things have been made for special purposes by a special god, my God.

Completely different spines, body shapes, claws, and heads.