Inaccuracies in sources

[theropod]

Talons may refer to their manus, there are certain morphological and functional similarities that are hard to dismiss (still, also differences of course).

[Godzillasaurus]

creature, yea it did say that they were sometimes used for fighting, even in gracile theropods like oviraptor ( ). It even went on to say that some were using their forearms for killing while their jaws were clearly the primary killing weapons

Also the problem with utilizing the claws for killing in the majority of groups is that they were so thick and ill-designed for slashing but instead for support. Having narrow and sharp hind claws would not provide decent enough support, especially for big theropods:

Theropod, that's possible but at the same time it claimed that the arms would be used for killing as opposed to the jaws, even in creatures like allosaurus! It claimed that the jaws would be grasping a prey animal and the claws would be tearing it apart, but it is quite the opposite actually

[Godzillasaurus]

And then here is this source that seems to describe dilophosaurus as being an obligate macropredator that would have killed large animals with its (still rather short) forearms and hind legs:

www.dinosaurfacts.org/dilophosaurus/35-dinosaurs/129-dilophosaurus?tmpl=component&print=1&page=

"It was possibly a scavenger, fossils showing a very weak attachment of the main upper jaw bones to the tip of the upper jaw. This connection is so weak that the teeth, although very sharp, were unable to stab the prey, instead using a plucking motion. This could be evidence that it plucked the meat from bodies ravaged by a larger predator, or that had died from old age or disease. It would not have been able to use its teeth to kill, and would have been forced to use its front claws and feet."

-You do realize that having a weakly-built premaxilla in a distinctive hook-like shape in possession of rather slenderized teeth is more-so an adaptation for handily plucking small animals, right? Just because it lacked macrophagous characteristics in its rostrum does not mean that it could kill efficiently with its hind legs and arms (the forelimbs would have played part in grappling, NOT killing); if it lacked macrophagous characteristics altogether that could very well imply that it hunted smaller animals overall. Seriously- "its teeth could not stab"? That's a lame argument, because stabbing and grasping go hand-in-hand (at least in the sense that he is seemingly implying it)...

I looked at a couple of other pages on the site, and I can say that a lot of what it says is, just like KDD, inaccurate. Just like KDD, it contradicts itself multiple times and says things that are completely hypothetical and stupid for passing off as fact. For example, it clearly stated that allosaurus had very powerful jaws and then later said that its jaws, despite being rather large, could not support such a massive bite force.

[Infinity Blade]

I just read a thread on Jurassic World regarding T.rex's abilities. Smh at that thread.

[theropod]

Godzillasaurus: Dilophosaurus has a kinetically attached premaxilla, which could be an adaption for grasping small animals, I’ll give you that. But it also has a fairly deep, robust maxilla with large, relatively robust teeth (CBR=0.58, CH/CBL=1.64). There really is no reason why it shouldn’t be capable of taking large animals.

Of course "large" can be hard to discern, because it is an extremely elongated animal with long neck and tail and a slender body, but what I mean is in comparison to its weight.

Theropod, that's possible but at the same time it claimed that the arms would be used for killing as opposed to the jaws, even in creatures like allosaurus! It claimed that the jaws would be grasping a prey animal and the claws would be tearing it apart, but it is quite the opposite actually

Yes, of course. Utilization of the claws, be it for or hind claws, to tear apart anything would be plain ridiculous.
Their primary purpose was gripping, and a resultant ability was obviously puncturing. I can certainly see the latter being deadly in some cases, considering the enourmous size and strenght that can be deduced for many of these structures, but that would be a sort of accidental by-product of clutching prey, rather than an active try to use them for killing, which is what the jaws were made for.
I was just referring to the use of the word "talon", which, in some theropods, I find quite fitting actually.

[Godzillasaurus]

The deepened rostrum could be evolutionary for prey type, but take note that dilophosaurus was a very primitive, Early Jurassic theropod whose characteristics may not be quite as developed and as such a shallower rostrum may not have been evolved yet.

Aside from rostral depth among a few other characteristics, dilophosaurus was quite similar to spinosaurus really (which as well possessed the hooked premaxilla and widely-spaced pointed teeth, which were also robust in their own regard).

And even for the hind limbs, in larger theropods like tyrannosaurus, the feet and claws among the very powerful upper regions were designed to provide support for the sheer weight of the animal as opposed to being used for feeding purposes (so thus thinner and more potent claws would in fact be disadvantageous because they were not strong enough). It is possible that they could have helped to anchor a carcass during feeding to provide for leverage, but as you said it is absolutely ludicrous to believe that they would have been used for traumatically wounding a prey animal. And even for dilophosaurus, its hind limbs too seemed very gracile and its claws were neither very large nor really designed for slashing in the first place (assuming that its morphology here was similar to that of more typical theropods)

[theropod]

The deepened rostrum could be evolutionary for prey type, but take note that dilophosaurus was a very primitive, Early Jurassic theropod whose characteristics may not be quite as developed and as such a shallower rostrum may not have been evolved yet.

Aside from rostral depth among a few other characteristics, dilophosaurus was quite similar to spinosaurus really (which as well possessed the hooked premaxilla and widely-spaced pointed teeth, which were also robust in their own regard).

No, they are not similar. They share exactly one characteristic, a diastema in the rostral toothrow.
This structure itself is different, the premaxilla of dilophosaurids is loosely attached (kinetic), that of spinosaurs is not^[1].

Dilophosaurus has ziphodont slicing teeth in its maxilla, and its skull is comparatively deeper than that of earlier theropods, not the other way around. Closely related taxa were around as early as the Norian (Zupaysaurus), for comparison D. wetherilli is from the Sinemurian or Pliensbachian.
If it was somehow specializing in small animals or fish, there would have been adaptions over such a long time period, resulting in characters supporting that–which are not present.

A use of the premaxilla for prey manipulation is in all likelyhood not an exception among theropods, premaxillary teeth are typically blunter and more peg-like than the lateral slicing dentition, also in animals like Allosaurus. Perhaps that is an adaption for bringing prey into forelimb range, where it could then be restrained while simulataneously eviscerating it with the jaws.

And even for the hind limbs, in larger theropods like tyrannosaurus, the feet and claws among the very powerful upper regions were designed to provide support for the sheer weight of the animal as opposed to being used for feeding purposes (so thus thinner and more potent claws would in fact be disadvantageous because they were not strong enough).

The hindlimb claws in large theropods served the purpose of increasing friction, and perhaps prey restraint in some taxa. What’s your point?
There’s nothing special about the hindlimb of Dilophosaurus as far as I can tell. The pes is elongated, with moderately large claws, as one would tend to expect from a mid-sized, cursorial theropod.

It is possible that they could have helped to anchor a carcass during feeding to provide for leverage, but as you said it is absolutely ludicrous to believe that they would have been used for traumatically wounding a prey animal.

Stepping on a living prey animal could undboutedly cause traumatic injuries. Which doesn’t mean the pedal unguals were meant to deliver them, as macrophagous theropods have other means of killing prey.

And even for dilophosaurus, its hind limbs too seemed very gracile and its claws were neither very large nor really designed for slashing in the first place (assuming that its morphology here was similar to that of more typical theropods)

Yeah…and how exactly makes being similar to typical theropods (dunno what the "more" is supposed to mean, because for all intends and purposes, Dilophosaurus is a typical theropod).
There’s no reason why Dilophosaurus would have had to rely on its legs to kill prey.

---

1. As Charig & Milner 1997 suggested for Baryonx in rebuttal to their own previous hypothesis. This likely applies to spinosaurines as well, since their premaxillae are always found in articulation with the resto of the snout, which seems rather extensively fused, unlike the typical theropod skull with a healthy degree of cranial kinesis and unfused elements, and unlike the condition apparently present in dilophosaurids (Tykoski & Rowe 2004).

[Godzillasaurus]

No, they are not similar. They share exactly one characteristic, a diastema in the rostral toothrow.
This structure itself is different, the premaxilla of dilophosaurids is loosely attached (kinetic), that of spinosaurs is not[1].

Ok, make of that what you will. Nonetheless there still are similarities, despite the connection being kinetic or not; both premaxillae were rather gracile and specialized structures where the teeth were more or less widely-spaced and idea for plucking small animals. Both animals possessed very specialized adaptations as opposed to the more typical macrophagous ones. It is baseless to assume that dilophosaurus could hunt large herbivores without mud hassle just because it was relatively large.

Dilophosaurus has ziphodont slicing teeth in its maxilla, and its skull is comparatively deeper than that of earlier theropods, not the other way around. Closely related taxa were around as early as the Norian (Zupaysaurus), for comparison D. wetherilli is from the Sinemurian or Pliensbachian.

What exactly were they shaped like cross-sectionally? I have not yet seen any descriptions or images of its teeth (thus from my POV a lot of true function was hypothetical). Besides, being serrated or compressed does not mean everything- as also it needs to be taken into account the actual jaw itself, width, and spacing of the teeth (in which case they all seemed rather similar to spinosaurus)

If it was somehow specializing in small animals or fish, there would have been adaptions over such a long time period, resulting in characters supporting that–which are not present.

How so?

A use of the premaxilla for prey manipulation is in all likelyhood not an exception among theropods, premaxillary teeth are typically blunter and more peg-like than the lateral slicing dentition, also in animals like Allosaurus. Perhaps that is an adaption for bringing prey into forelimb range, where it could then be restrained while simulataneously eviscerating it with the jaws.

But the premaxillae of allosaurs were in no way specialized or cleft-like as we see in spinosaurs or dilophosaurus. Not to mention the teeth in that region were typically very short and blunt (not as well adapted for slashing as they are typically broader and more d-shaped in cross-section, but yet they sort of curved inwards and were rather short). Allosaurus and other animals with more broadened premaxillae will most likely be attacking without grappling at all (and instead would have attacked quickly in specific regions. This can be applicable to many large-skulled theropods). While they were certainly better suited for gripping than the more posterior lateral teeth, they and the bone at which they were rooted were not ideal for gripping or wounding anything.

The hindlimb claws in large theropods served the purpose of increasing friction, and perhaps prey restraint in some taxa. What’s your point?
There’s nothing special about the hindlimb of Dilophosaurus as far as I can tell. The pes is elongated, with moderately large claws, as one would tend to expect from a mid-sized, cursorial theropod.

Prey restriction is a definitely very possible conjecture to believe, especially when the feet are being used as clamps of a carcass, but the KDD website (and the other one which I posted) is wrong on so many levels as there is in fact little evidence that theropod genera like allosaurus or dilophosaurus utilized their claws for killing and not their jaws (among others of course...)

Stepping on a living prey animal could undboutedly cause traumatic injuries. Which doesn’t mean the pedal unguals were meant to deliver them, as macrophagous theropods have other means of killing prey.

I agree, but this does not contradict what I am saying at all. Sure, the weight of the theropod in conjunction with its robust, hook-like claws could definitely be used to deliver traumatic force to a grounded herbivore, but you said it best that the foot-claw combination probably could not tear effectively because in most theropods they were poorly designed for such.

There’s no reason why Dilophosaurus would have had to rely on its legs to kill prey.

Exactly, because as with most large theropods its hind limbs probably could not slash or tear effectively (also note balance in this regard, as Ausar pointed out); and as long as its forelimbs and jaws alone could take its evolved prey it would have done fine. Although maniraptorans with enlarged second claws would have probably utilized them as their primary weapons (whether it be for slashing or gripping, as I read that they probably could not slash well surprisingly despite the obvious connections one would make), larger and/or more macrophagous theropods would have relied on their large jaws for killing with little emphasis on limbs (which is probably why most large theropods had very large skulls and dentition and very short forearms that were practically rudimentary in families like tyrannosauridae or abelisauridae).

[theropod]

Ok, make of that what you will. Nonetheless there still are
similarities, despite the connection being kinetic or not; both
premaxillae were rather gracile and specialized structures where the
teeth were more or less widely-spaced and idea for plucking small
animals. Both animals possessed very specialized adaptations as opposed
to the more typical macrophagous ones.

As I wrote: "They share exactly one characteristic, a diastema in the rostral toothrow".
How from that alone people tend to conclude dilophosaurids were limited to small prey is beyond me. There seems to be nothing particularly specialized about its jaw apparatus as a whole, and nothing precluding the acquisition of large prey.

 It is baseless to assume that dilophosaurus could hunt large herbivores
without mud hassle just because it was relatively large.

This has nothing to do with body size, it’s about relative prey size. It is baseless to assume Dilophosaurus could not have hunted large animals.

What exactly were they shaped like cross-sectionally?

I already posted that, they were ziphodont, with an average crown-base-ratio of 0.59.

 I have not yet seen any descriptions or images of its teeth

I have seen the actual teeth, or at least casts in museums before.

Besides, being serrated or compressed does not mean everything- as also
it needs to be taken into account the actual jaw itself, width, and
spacing of the teeth (in which case they all seemed rather similar to
spinosaurus)

Are you suggesting an animal with compressed, serrated slicing teeth (not to mention a deep skull) will have similar tooth function to an animal with conical teeth just…because its teeth seem somehow superficially similar to you?


The teeth are long, but mostly because they have got a large portion of root exposed in many photos and technical drawings, just like the T. rex specimen BHI 3033. The real proportions are not entirely clear, various reconstructions show them differently.
But what is actually completely clear is that Dilophosaurus had ziphodont slicing teeth in its maxilla, this condition has been described in publications and is consistent with morphometric data from Smith et al. 2005.

How so?

Evolution.
You were suggesting it was so "primitive" that one couldn’t expect adaptions for such a lifestyle no matter whether it had them or not. I pointed out that its lineage (in all likelyhood apex predators) had already been evolving for tens of millions of years, and that one has to expect adaptions.

But the premaxillae of allosaurs were in no way specialized or cleft-like as we see in spinosaurs or dilophosaurus.

That is irrelevant. The premaxillae of dilophosaurids are also in no way comparable to those of spinosaurids, just vaguely similar in terms of how they look, and yet you are comparing them. All that is known about the premaxilla of Dilophosaurus is that it was likely used for grasping, and as I wrote, that’s not an exception among theropods.

 Not to mention the teeth in that region were typically very short and
blunt (not as well adapted for slashing as they are typically broader
and more d-shaped in cross-section, but yet they sort of curved inwards
and were rather short). Allosaurus and other animals with more broadened
premaxillae will most likely be attacking without grappling at all (and
instead would have attacked quickly in specific regions. This can be
applicable to many large-skulled theropods).  While they were certainly better suited for gripping than the more
posterior lateral teeth, they and the bone at which they were rooted
were not ideal for gripping or wounding anything.

That isn’t making sense. At first, you are listing the very adaptions  Allosaurid premaxillary teeth had for grasping, then you are somehow arguing against them being used in that manner, and that despite the bone they were rooted in being easily more robust than the equivalent in the animals you consider suited for grasping (spinosaurs, apparently dilophosaurs). And nobody is talking about "ideal" except for you. The "ideal" snout and tooth design for gripping is that which is found in crocodilians, but neither allosaurs not ceratosaurs have it. Still, adaptions for grasping are present in both to some extent (and also in Torvosaurus), and they do not automatically mean that the animal only killed small prey.
Allosaurus and similar theropods had adaptions for grappling for a reason, they undoubtedly employed it. I already elaborated on the way that seems most likely.

I agree, but this does not contradict what I am saying at all.

It does, if you are suggesting that Dilophosaurus wasn’t suitable for killing large prey and use its legs (which weren’t used for that purpose anyway) as an argument.

There’s no reason why Dilophosaurus would have had to rely on its legs to kill prey.

Exactly,
because as with most large theropods its hind limbs probably could not
slash or tear effectively (also note balance in this regard, as Ausar
pointed out);

I fail to see the relation here. Dilophosaurus did not need its löegs for killing, simply because its jaws were fully suitable for the task.

Although maniraptorans with enlarged second claws would have probably
utilized them as their primary weapons (whether it be for slashing or
gripping, as I read that they probably could not slash well surprisingly
despite the obvious connections one would make)

The doubts about that point are justified considering there are very few animals that actually use their claws for slashing, and none that kill this way. However, I don’t think the slasher-hypothesis should be dismissed, as dromaeosaur claws (at least in those specimens I have seen) are unusually compressed laterally and bear a carina on the inside. It is certainly possible that with the addition of a keratin sheath these structures would have been sharp enough to be used for slicing, and due to their sheer lenght that could be quite deadly. Mere puncturing would still likely be an important purpose too.

, larger and/or more
macrophagous theropods

I don’t think there are were any theropods significantly more macrophagous than dromaeosaurs.

would have relied on their large jaws for killing
with little emphasis on limbs (which is probably why most large
theropods had very large skulls and dentition and very short forearms
that were practically rudimentary in families like tyrannosauridae or
abelisauridae).

That can be attributed to multiple factors, but it doesn’t occur in all families of theropods, and not everywhere to the same degree.

[Godzillasaurus]

You guys can feel free to find inaccuracies in the source that I posted and/or post other terrible sources

[theropod]

I forgot to mention that oviraptorids aren’t actually gracile (really short tails and compact bodies), and I read that their claws are raptorial (unlike those of ornithomimids, which you may be thinking of). There’s really nothing to suggest that they were not used for fighting.

And theropods using their forelimbs for killing has at times been suggested in the literature. That doesn’t make it the most likely of hypotheses considering most theropods have jaws perfectly suited for killing, but it’s not impossible that it happened, especially with smaller prey.

[Godzillasaurus]

Well having a short tail only means something when comparing it to another animal with a proportionally longer tail at length parity (like velociraptor), in which case the latter's longer tail will make it "more gracile" by the virtue of proportions alone. That doesn't make the creature's entire body any more or less robust. I have never heard of the raptorial claw idea for oviraptorids; not only did they lack the specialized and enlarged second claw of dromeosaurids which were used most likely for killing, but it would have also been almost completely unnecessary given the fact that they were only suited for feeding on small animals and probably vegetation as well. A macrophagous killing characteristic like what we find in creatures with recurved, serrated teeth such as velociraptor would be unnecessary for an animal that was ill-suited for feeding on larger dinosaurs. Unless of course that claw could be used for defense, but its speed and agility would have likely been its primary defense mechanism if I may say so myself.

And for your second paragraph, that still doesn't really make it a valid theory. Many derived theropods evolved large, powerful jaws and longish teeth (for varying purposes among different groups albeit, but still it is the same principle) as an adaptation for killing other vertebrates. Generally, save for spinosaurids (which would have used their forearms for grasping fish if not for tearing apart anything), predatory theropods with greater emphasis on jaw and tooth function also possessed very short and almost completely useless forearms.

I must admit that I am on the edge about dromeosaurids; they did not possess the largest or strongest jaws but as well possessed long and prominent forelimbs. One might agree that they could have been used for grappling, but I am not so sure about that. They were shaped like bird wings (obvious evolutionary connection is obvious!): being long and having the wrists motioned backwards. This does not seem like the ideal shape for grasping at all, especially when it has actually been theorized that the hind limbs had that function (as apparently the enlarged second claw was actually ill-suited for tearing but was instead terrific at hooking): royalsocietypublishing.org/content/2/1/110

So unless dromeosaurids had capabilities for large wrist movement, I definitely concur that their hind limbs would be used for securing pray. The forearms might provide a tad bit of grabbing support, but not enough to be considered significant grasping weapons

[Ceratodromeus]

So i know the thread is old but the 'fights' on a jurassic world fan fiction site brought up by ausar were written by me when i was younger...i know...trust me they are terrible to go back and read but anyway, I was (apparently) quite a topic of discussion in those days for this forum, but trying to use this in a thread about 'inaccurate sources' when the fan fiction is on a fan site for a science fiction movie numbs my brain.

The talk about innacuracies in childrens sites are equally face palm inducing, like c'mon. do you really expect a children's website to be on the cutting edge of paleontology, with sophisticated diction for their young audience? There is indeed an 'excuse', it's aimed towards children. if you don't like it simply avoid it, why you're seeking these websites out when you're above the target audience is beyond me.

again i know this thread has been dead but i've been triggered apparently.

[Infinity Blade]

To be honest, I'm not sure what I was exactly thinking when I implied that a forum (at least by itself; i.e. not whatever other resources its members may cite) really counts as a 'source'.

Anyway, to contribute to the thread here, there are two websites (one of which must have parroted the other, given how they say the exact same thing) that say the exact same thing about tyrannosaur foot claws: that they were "...short, rounded, and hoof-like". These (hyperlink) are not "hoof-like".

www.kheper.net/evolution/dinosauria/Tyrannosauridae.htm
palaeos.com/vertebrates/coelurosauria/tyrannosauridae.html