Allosaurus fragilis vs Daspletosaurus torosus

[Fragillimus335]

I favor Tyrannosaurids over all other large theropods at weight parity.

[theropod]

Godzillasaurus: Allosaurus would kill by severing the carotid artery and or vena jugularis. as a side effect, it will of coruse deal heavy damage to the muscular and ligamentous system in the neck.

The reliance on ventroflexion does not restrict it in the areas it could bite. It would likely go for the throat, just like most animals, whether it employed slashing or biting.

[Godzillasaurus]

Can you define ventroflexion for me please? I am looking it up online, but I cannot seem to find anything that I can firmly understand.

By "slashing" are you referring to ripping, specifically being done with backward motions of the creature's skull? In which case, this seems to be the more likely style by which it used to kill. Perpendicular biting through the use of a moderately-powerful bite in combination with deep pierce wounds to damage internal structures does not seem likely based on what we know about allosaurus. Most likely, allosaurus did not use biting to kill but instead through the use of the hatchet-bite; its bite was nothing special and in fact is not a necessity for it to be a decent hunter. Unlike spinosaurus, perpendicular biting for allosaurus is not a logical hypothesis; both animals probably did not exert very powerful bites to begin with (likely around 2-3 tons for the former and around 3-4 tons for the latter, at parity of course), and their respective lifestyles did not require such. Unlike the other, spinosaurus' lifestyle and predation all seemed to be closely related to its high capacity for puncturing into the hides of tough-skinned fish: its teeth were pointed and relatively slender/elongate (to a rather high degree), its bite force was moderate at best (again, not completely weak, but not monstrously strong either. The 2-3 ton figure seems most accurate for it), and its snout was reasonably strong. All of these physical features indicate that the creature's lifestyle was employed by a particularly high aptitude to pierce/grip, which is in immediate correlation with its diet of large and potentially tough-skinned fish.

Allosaurus' heavy reliance on backward pulling seems to be the most logical explanation for its preferred killing style. I do remember reading that allosaurus probably fed in a similar way to the modern falcon (or any bird of prey really) through the use of biomechanics. What this seems to imply is that allosaurus would have fed not like tyrannosaurids with forceful shaking (similar to how broad-snouted crocodilians typically dismember moderately-sized prey) but instead with pulling. This is really no surprise.

[theropod]

flexion = decrease of the angle in a structure (such as when you flex your fingers to form a fist)
ventral = towards the belly (i.e. the opposite of dorsal) = in theropods that equals facing down

Ventroflexion = flexion of a structure (e.g. the vertebral collumn) in ventral direction. Ventroflexion of the neck and craniocervical joint (in combination with tearing motions, i.e. head retraction) evidently played an important role in the feeding styles of carnosaurs (especially allosauridae) and some other theropods, in that it augmented their bite forces. This is supported by the posession of large ventroflexive moment arms and attachments for various muscles.

By "slashing" I refer to the kind of quick tooth-on-opponent contact induced by the postcranial musculature, with relatively little mandibular involvement, that is employed in some form or another by most slicers (and some other animals), e.g. baboons, komodo monitors, some sharks. This is a somewhat poorly defined term and it is fairly variable, but what we can be fairly sure of is that Allosaurus also used its jaws to engage prey with rapid attacks to slash through its tissues, namely by some form of downward strike or very quick bite, not with prolongued gripping and holding.

Benefits are the efficiency, the reduced need for resistance, especially in directions other than those paralell to the primary forces that are delivered (depression and pulling), the resulting lighter skull allowing for a quicker strike, and that it enables the animal to have a weaker bite forces and wider gape and labiolingually compressed slicing teeth with high aptitude at tearing. All those render this a preferred style of attack for "gigantophagous" animals.
However the vast majority of macrophagous animals have at least some degree of cutting ability in their teeth (unlike the blunt grinding or cracking teeth common to molluskivorous or herbivorous animals), which seems to be almost a necessity for killing large animals.

The jaws of Allosaurus would have been a very serious thing to mess with. It’s craniocervical architekture suggests very high head mobility, gape and capacity of very quick attacks, combined with rows of teeth that acted like an oversized, very sharp saw. Bitemarks on bones and the skull strenght attest to a feeding and prey aquisition style that involved large forces in perpendicular and anteroposterior directions, and extant examples demonstrate how gruesomely effective bites of this kind can be on various body regions.

[Godzillasaurus]

By "slashing" I refer to the kind of quick tooth-on-opponent contact induced by the postcranial musculature, with relatively little mandibular involvement, that is employed in some form or another by most slicers (and some other animals), e.g. baboons, komodo monitors, some sharks. This is a somewhat poorly defined term and it is fairly variable, but what we can be fairly sure of is that Allosaurus also used its jaws to engage prey with rapid attacks to slash through its tissues, namely by some form of downward strike or very quick bite, not with prolongued gripping and holding.

That is a very well-worded paragraph right there. I agree that "slashing" is quite poorly defined, but at least we can infer that allosaurus used a similar means to dispatch and kill prey regardless of the proper definition for it.

However the vast majority of macrophagous animals have at least some degree of cutting ability in their teeth (unlike the blunt grinding or cracking teeth common to molluskivorous or herbivorous animals), which seems to be almost a necessity for killing large animals.

Gigantophagous theropods such as allosaurus itself (it would have preyed most likely on creatures like diplodocus) fit the bill here as you said. But I wouldn't necessarily say that this applies to most macrophagous animals, extant or extinct. All animals have a morphology, anatomy, and physiology adapted to cope with their ecologies and most common prey items, so blade-like slashing dentition and a lack of exceptional snout robusticity and bite force are really no surprise; they allow the creature to effectively slice open the flanks of a larger prey animal without causing too much stress on the skull itself (as you have previously stated). Macrophagy seems to be a broader term while gigantophagy is a more specified term (such as science -> biology -> zoology -> mammology), as macrophagous animals in general do not have to possess this similar morphology and slashing-related killing style to be effective predators (take tyrannosaurids and crocodilians for example), it is all a matter of what kind of prey an animal is adapted to hunt and kill.

I mean, this is where many of the theories about an extinct animal's lifestyle come from most of all. Just as how it is no surprise why primarily piscivorous animals such as spinosaurus possess relatively slender and specialized snouts and generally quite sharp conical teeth (more sharply pointed than either allosaurus or tyrannosaurus. Evident here) allowing for greater aptitude for gripping fish. Obviously spinosaurus fits the bill perfectly here. The point being, being a macrophage does not necessarily have to merit a similar morphology to allosaurus.

[theropod]

lol, "gigantophagous" as a term actually appears to be our own invention, but it's a useful one, so...yes, gigantophagous refers to predation on animals (considerably) larger than the predator. Macrophagous refers to predation on large animals (wherein "large" is not strongly defined, but should probably at least be the biggest portion of the predators own body mass)

What I meant was that all predators have more pointed teeth than non-predators, and that macrophagous ones typically have at least some degree of carination on at least some teeth.

Also, in the same family, if it contains both, slashers/slicers are typically more macrophagous (e.g. great white shark, komodo dragon), while grippers or crushers are rather durophagous/herbivorous (e.g.rock monitor, tegu), or take smaller prey (e.g. mako shark), often despite much higher bite forces in the latter.

More pointed and/or sharp teeth are usually associated with greater proficiency at macrophagy, even though the exact degree to which an animal is macrophagous and that to which it is a slicer/crusher are hard to quantify and depend on numerous factors.
You even see this principle demonstrated where teeth aren’t involved; birds of prey with strong squeezing strenghts and less well-developed claws (e.g. owls) rely on grip strenght to constrict smaller animals than those that rely on long stabbing talons (e.g. accipitrids) and weaker grips. Of course to every rule in biology there tend to be exceptions, depending on other factors, but this is the general trend linked to the functional morphology of weaponery systems.

If predatory animals develope increased specialization for blunt force, there is usually a very good ecological or evolutionary reason for doing so, that makes it worth the payoffs involved. E.g. mammals cannot afford loosing teeth, and crocodilians have a semi-aquatic ecology that makes gripping and drowning a very simple killing strategy.

Regardless of that, in general, predators, even if they are primarily crushers, have more pointed, and typically carinated teeth (e.g. T. rex or Pliosaurus. Obviously not "sharp" compared to an animal one would label a "slicer", but a whole lot more so than a placodont’s or elephant’s). Those are simply necessary in dispatching a big animal.

PS:An important exception are animals that kill by precision, such as cats (but even they have somewhat sharp carnassials, although their sharpness is not used for killing). Pack-hunting also complicates comparisons. These two are important reasons why mammalian predators are capable of subduing large prey even though they do not have ziphodont dentition or particularly large gapes and skulls.

[Godzillasaurus]

What I meant was that all predators have more pointed teeth than non-predators, and that macrophagous ones typically have at least some degree of carination on at least some teeth.

Not ALL predators have sharp teeth in any regard (whether it be pointed or carinated); molluscivores tend to have particularly blunter and even quite flattened dentition (such as the Chinese alligator, which contrasts heavily to he vast majority of other crocodilians in terms of diet and tooth shape), and insectivores often don't even have teeth at all (or at least many in that regard). Tooth arrangement and morphology is heavily indicative of what something preys on, not necessarily whether or not that said creature is a predator.

More pointed and/or sharp teeth are usually associated with greater proficiency at macrophagy, even though the exact degree to which an animal is macrophagous and that to which it is a slicer/crusher are hard to quantify and depend on numerous factors.

Sharper teeth point-wise tend to be possessed by animals with greater proficiency at gripping smaller prey as opposed to killing large animals. Just look at spinosaurus, again; unlike allosaurus and similar theropods (e.g. allosauria as a whole), its teeth were advanced at gripping strength and of course deep impalement/stabbing. Much like your bird of prey analogy, it did not rely on powerful force to drive its teeth deeply, as they were already proficient at doing so given their sharp and generally elongated morphology (they were generally sharper in this regard than the dentition of allosaurs, which specialized mainly in cutting as opposed to piercing).

[Deleted]

This looks pretty even, maybe leaning toward Daspleto.

[dinosauria101]

Daspletosaurus wins, it's much larger and has a likely deadlier bite

[dinosauria101]

Size chart from DPF



arethousleepy

This match is more of a classic than Allosaurus fragilis vs Albertosaurus you requested on Carnivora, and it's not viewed as a mismatch

[elosha11]

Close, but if the above comparison is accurate, I give it to Allosaurus. A bit larger, it appears, and probably a wider gape which could really help its slashing attack. Daspletosaurus has a stronger head and neck. Query, does Allosaurus have any ability to grip and slash with its front legs?

[dinosauria101]

Jul 3, 2019 7:13:25 GMT 5 elosha11 said:

Close, but if the above comparison is accurate, I give it to Allosaurus.  1: A bit larger, it appears, and probably a wider gape which could really help its slashing attack. Daspletosaurus has a stronger head and neck. 2: Query, does Allosaurus have any ability to grip and slash with its front legs?

1: It may surprise you to know this, but Daspletosaurus is actually the bigger of the 2; 2.8 tons vs 2 tons. That skeletal though is a bit shrinkwrapped. Maybe this one should've been used:


2: Yes, somewhat. That might help a little, but I'd give this to Das 65/35

[dromaeosauridae117]

Hmm. Interesting matchup. My vote would have to go to the Daspletosaurus. More robustly built, as well as having a much more powerful bite.

[Infinity Blade]

Query, does Allosaurus have any ability to grip and slash with its front legs?

I think range of motion studies on Allosaurus forelimbs suggest limited flexion when moving the arms forward, but these also don't seem to take into account cartilage that would extend the range of motion to some extent (published relatively recently). Now, I don't know how much more forward it could move its forelimbs with that, but I just can't fathom forelimbs that robust and muscular with huge meat hooks for claws that probably put those of any living land predator to shame not having the aforementioned gripping and slashing abilities. So short answer, yes.

[dinosauria101]

Infinity Blade
Have you taken into account the tyrannosaur's size advantage (2 tons vs 2.8 tons) when you decided on 50/50? If so, why would this be a 50/50 at average weights? I'm curious to hear your reasons