Tyrannosaurus rex vs. African Bush Elephant

[Life]

T-rex is likely to make a lunch of any modern era elephant. One aspect that is often overlooked is animal psychology, gigantic theropods are likely to instill fear in many potential prey due to their sheer size, body structure (height factor) and predatory capabilities. Elephants are not immune to scare-factor (I have seen a live footage in a documentary which affirms this point). A lone elephant is likely to feel intimidated and make a blunder in this kind of scenario, it is likely to end up getting eaten.

In addition, if we count experience factor then an adult T-rex would have ample experience of dealing with powerful and dangerous prey. In contrast, no modern era elephant have such exposure.

At maximum, an elephant might give T-rex some challenge if it isn't psychologically intimidated from the gigantic theropod but I don't see elephant winning in this kind of contest unless a theropod is badly wounded or something prior to this hypothetical encounter. Modern era predators hold no candle to power and might of gigantic theropods, IMO. And my assessment isn't just about T-rex, it is about gigantic theropods in general.

I would also caution people to assess predatory potential of a theropod on the basis of its weight alone. Body mass isn't much of a deciding factor, body structure (height factor), physical strength and predatory abilities are main factors that make difference.

Based on sheer size, who would imagine that a honey badger is a powerful animal?

[Vodmeister]

Mar 22, 2014 17:31:45 GMT 5 Infinity Blade said:

Psychology is everything. Fight vs flight. In such a scenario, I'd imagine that the T-Rex would be quite comfortable with an elephant given that it regularly dealt with herbivores several tonnes larger than itself. On the flip side, I'm not exactly sure how comfortable an elephant would be around a tyrannosaurus rex!

[malikc6]

This fight is difficult to visualize. I'm giving it to the T Rex though. I think one bite would spell disaster for the elephant. Maybe if the elephant charged the dinosaur and crashed into it, it could win maybe.

[Deleted]

Mar 25, 2014 13:38:45 GMT 5 Life said:

Body mass isn't much of a deciding factor
Based on sheer size, who would imagine that a honey badger is a powerful animal?

Well, the influence of body mass differences as a factor in battles is actually proportional to the scale of the combatants.

At the scale of the honey badger, your first (quoted) statement is correct, but at the scale of humans, it's so much of a factor that boxing competitions have to be divided into classes by body mass to ensure a fair fight as much as possible. At multi-tonne scales like this one, body mass is one of the biggest factors in the fight.

People, for some reason, mostly talk about the 5+ tonne creatures when talking about theropods, so body mass is going to be brought up as a factor quite often, and for a good reason.

[Life]

I doubt that an elephant would attempt to charge a gigantic theropod, this is a very risky maneuver on part of an elephant. Even if an elephant hypothetically does, it isn't like a theropod cannot attempt to evade or grapple and attempt to bite off the trunk of the elephant. I never found this charging logic convincing.

[Life]

Mar 25, 2014 13:49:01 GMT 5 @brolyeuphyfusion said:

Mar 25, 2014 13:38:45 GMT 5 Life said:

Body mass isn't much of a deciding factor
Based on sheer size, who would imagine that a honey badger is a powerful animal?

Well, the influence of body mass differences as a factor in battles is actually proportional to the scale of the combatants.

At the scale of the honey badger, your first (quoted) statement is correct, but at the scale of humans, it's so much of a factor that boxing competitions have to be divided into classes by body mass to ensure a fair fight as much as possible. At multi-tonne scales like this one, body mass is one of the biggest factors in the fight.

People, for some reason, mostly talk about the 5+ tonne creatures when talking about theropods, so body mass is going to be brought up as a factor quite often, and for a good reason.

I see your point. However, deciding predatory potential on the basis of sheer size alone is not a sound thought, IMO. A gigantic theropod have so many advantages on its side and not just the size factor. These animals were tall (good posture for landing bites on prey) and well-armed. A single bite from a theropod is going to be fatal for most potential prey barring large sauropods.

[malikc6]

The elephant would likely retreat seeing a creature like that. Once again, this fight is hard to picture for me.

[Vodmeister]

The elephant's only chance would be to gore the T-Rex from the flanks. Head-on, it is doomed against the theropod.

[Deleted]

Mar 25, 2014 13:49:22 GMT 5 Life said:

I doubt that an elephant would charge a gigantic theropod. It is a very risky maneuver on part of an elephant. Even if an elephant hypothetically does, it isn't like a theropod cannot attempt to evade or grapple and attempt to bite off the trunk of the elephant. I never found this charging logic convincing.

Yeah, people think that the theropod would just stand there and let itself get hit. Modern theropods(aka birds) don't offer themselves to get hit, there's absolutely no reason to say that prehistoric theropods are gonna be the opposite.

[Infinity Blade]

You guys have excellent points.

I think Gato Gordo said in the Carnivora variant of this matchup that psychology won't be a factor, giving automobiles as an example (they haven't seen them for most of the time they've existed). I don't think this is fair. Do elephants "deal" with automobiles that large? I'm not sure. I could definitely be wrong, but as Life pointed out, size isn't everything in intimidation. Body structure and armament matter too. And while getting hit by a car/truck will do extreme damage (absolutely no denying that), from what I know, you don't exactly see a lot of incidents of people in automobiles running over elephants (imagine the damage).

Whereas this is a hypothetical fight to the death with a predator that would commonly kill prey somewhat like this.

[creature386]

As for automobiles, remember that you don't know if an animal who seemingly is not afraid of automobiles sees it for the first time. Given that less and less animals can avoid humans, this is unlikely. But I agree that psychology is not that important in a life to death battle.
I don't understand the car example though. Most humans won't even have a reason to try killing an elephant like that, they have better ways of doing so.

[Infinity Blade]

I think psychology will help in the fact what while both animals are inclined to kill each other, one will be more uneasy, hold back more on attacks, and more susceptible to making a blunder as Vodmeister said.

[Deleted]

Elephant wins, but with difficulty.

[Infinity Blade]

The elephant will become tyrannosaur food. The elephant just isn't beating such an exceptionally well-armed, relatively fast, specialized predator of megaherbivores (just as big as the elephant, mind you) with arguably more reach than even the longest modern elephant tusks. It doesn't help the elephant that it has never had to contend with a predator with all these attributes that at the same time is just as massive as itself.

The only real advantage the elephant has to its name is stability, and I've done what I can to address that.

Edit: here's some information, with sources, about how something like Triceratops compares with an African elephant (and also rhinos, relative to size). Of all the bulky megaherbivores armed with goring weapons, something like Triceratops would be the best at dealing with colossal predators like T. rex.

Appendicular anatomy:

In his 1986 book The Dinosaur Heresies, Dr. Robert Bakker notes that ceratopsid legs were thicker, longer, and more powerfully muscled than those of equal sized rhinos, and certainly much stronger than those of an elephant.




In this interview, paleontologist Gregory S. Paul also notes how ceratopsids were much more powerfully built than rhinos in bone robustness, most likely an adaptation for fighting off similar sized predators (i.e. tyrannosaurids).

Ceratopsians were much more strongly built than rhinos in terms of bone robustness. Also, they had enormous pelvic girdles, and the limbs were longer than rhinos of equal mass. All this implies that ceratopsids had larger leg muscles than rhinos. This was probably to give the the ability to fight off the enormous tyrannosaurids - of course Happ has just shown that Tyrannosaurus engaged in direct combat with Triceratops, one of the latter having healed bite marks on its skull. Rhinos do not have to contend with such super predators.

The Prehistoric Times Interview: Gregory S. Paul

Ceratopsid limbs were much more powerfully muscled than those of rhinos (just look at how the ilium compares, for instance), with its leg musculature once being compared to that of a giant bird (which have enormous leg muscles for their size).

On the other hand, the great horned dinosaurs had much larger areas for muscle attachments than seen in rhinos, indicating a much more powerful musculature.

The Complete Dinosaur

Galloping animals need a great deal of hindlimb thrust. This can be estimated from the size of the attachments for the muscles, preserved as scars on the bones of hindlimbs. Triceratops has relatively larger muscle attachments than found in rhinos or elephants. This suggests that Triceratops would have been a more powerful runner, judged weight for weight, than an elephant or a rhino. Interestingly, though, the arrangement of the musculature of the Triceratops hindlimb looks rather more like that of a large bird than a rhino.

In Search of Deep Time: Beyond the Fossil Record to a New History of Life

Rhino legs are, in turn, more powerfully muscled than those of proboscideans, so that tells you how much more muscular the legs of a Triceratops would be compared to those of an elephant.

Also, the leg muscles of galloping rhinos are more powerfully built than those of elephants.

Dinosaur Models: The Good, The Bad, And Using Them To Estimate the Mass of Dinosaurs

Ceratopsids clearly have proportionately longer scapulae than do rhinos, providing more room for muscles and greater leverage for propulsion.

In contrast, a long scapular blade could potentially provide great mechanical leverage and thus enhance propulsive power from the forelimb.

www.gspauldino.com/Forelimb.pdf
Forelimb posture in neoceratopsian dinosaurs: implications for gait and locomotion

Paul & Christiansen (2001) found that overall, ceratopsians (including both ceratopsid and non-ceratopsid taxa) "...have strength indicator values comparable to those of rhinos and large bovids, and distinctly higher than in elephants or hippos. The tibial values are even considerably higher than in extant rhinos."

They also note that elephant long bones are not particularly robust for their size, given their long length and rather slender shafts.

Figure 1A is a comparison of humeral length and total forelimb length to body mass in mammals and ceratopsian dinosaurs, the latter given as the combined lengths of humerus, radius and the longest metacarpal. Total forelimb length in mammals shows negative allometry with size. Additionally, large species have even shorter limbs than predicted, presumably as a means of preserving limb bone strength by reducing the size of the lever arm of the bending and torsional moments of the diaphyses (Christiansen, 1999a). However, the African elephant is long-limbed and has a total forelimb length close to the predicted value, probably due to the markedly decreased locomotory performance of elephants compared to rhinos (Alexander et al., 1979b; Alexander & Pond, 1992). Having long limbs and rather slender diaphyses (Alexander et al., 1979a; Christiansen, 1997, 1999a, 1999b) at a large body mass makes running impossible, as the limb bones are not strong enough to allow running, as pointed out by Alexander et al. (1979b).

www.gspauldino.com/GaiaNeoceratopsian.pdf
Limb Bone Scaling, Limb Proportions, and Bone Strength in Neoceratopsian Dinosaurs

However, it's worth noting that the study above compares strength indicator values in taxa that are widely variable in body mass. Because strength indicators do not scale linearly with body mass, but instead with (body mass)^1/3, directly comparing the strength indicator values of animals of highly different body mass is tricky business. Therefore, Casinos (1996) scaled all the species sampled below at hypothetical body mass parity (the same body mass as Megatherium americanum, 3.8 tonnes). And as we can see here, everything I've said above regarding bone strength is corroborated. Triceratops has an even stronger humerus than a white rhinoceros (~12.4% stronger), let alone an elephant (>2 times stronger). The strength difference is significantly more pronounced when comparing femora among the three.



And for all their body mass, elephants do not have particularly large, powerful leg muscles for their size.

Also, unlike elephants, the humeral muscle scars [of stegosaurs] were large...

Source: Currie, P.J.; Padian, K. (1997). Encyclopedia of Dinosaurs. Academic Press.

Despite proboscideans’ enormous weight, they do not have very developed limb musculature (Knight 1947; Haynes 1991; Paul 1997).

The inability of elephants and practically all proboscideans to perform true running with a suspended phase may be due to a combination of different factors or features: (i) the diaphysis of the femur and other long bones is larger in lateromedial than anteroposterior diameters (Christiansen 2007); (ii) the cnemial crest of the tibia is relatively poorly developed, indicating that the muscles attached there are not as strong as in other running animals such as rhinos and horses (Haynes 1991); (iii) the ilium is realtively short and therefore not suitable for big muscle attachments (Paul 1998), indicating a low ratio between limb muscle mass and total body mass (Taylor et al. 1974; Weibel et al. 1987); (iv) the proximal segments of the appendicular skeleton (scapula/humerus humerus/ulna and pelvis/femur) are poorly flexed; (v) the relatively long humerus and femur, short tibia and the composition of the manus and pedi with very short and relatively rigid distal elements (especially metacarpals and metatarsals) and big pads are not suitable for a strong propulsive phase of the limb stroke. All these characteristics are highly divergent from those of most running mammals and birds (Paul 1998, 2009; Christiansen and Paul 2000; Christiansen 2007) and have more influence than the high body mass of elephants because calf and juvenile individuals are also unable to perform true running

Source: Larramendi, A. (2016). Shoulder height, body mass, and shape of proboscideans. Acta Palaeontologica Polonica 61 (3): 537–574.

There is a correlation between muscle attachment area and speed among birds and mammals. Fast running cheetah, canids, gazelles and horses have more mass than slower cattle and goats (Taylor et al., 1974; Hoppler et al., 1987). In slow elephants and humans the ilium is not long, and anchors a narrow thigh musculature. Faster running mammals and birds have longer ilia that anchor a broader, more powerful thigh musculature. Birds have large cnemial crests and hypotarsi that anchor a powerful "drumstick" shank musculature.

Source: Paul, G.S. (1998). Limb design, function and running performance in ostrich-mimics and tyrannosaurs. Gaia, 257-270.

There is a tendency to restore the limbs of these slow giants [sauropods and stegosaurs] as heavily muscled pillars like the fat-limbed brachiosaurs in the movie Jurassic Park. This is a mistake. Slow-moving sauropods and stegosaurs should have had long, lightly muscled legs, like those of elephants.

Source: Paul, G.S. (2003). The Scientific American Book of Dinosaurs.

Axial anatomy:

Moving away from appendicular anatomy, Triceratops had a massively wide rib cage, as you can see in this 3D reconstruction by researcher Pasha van Bijlert (link->).



Loxodonta africana looks significantly less impressive. Ergo, Triceratops is clearly the bulkier animal.


(Source: Larramendi et al. (2017))

Ceratopsids like Triceratops also had ossified tendons that braced the backbone, an adaptation that elephants obviously lack. A juvenile chasmosaurine specimen shows that these should have existed in the neck, trunk, and sacral regions (Currie et al., 2016), making the ossified tendons extensively distributed along the ceratopsid vertebral column.

Here's a visual of this from The Scientific American Book of Dinosaurs.


Also, look at an elephant's skeleton-> and compare it to that of a Triceratops->. Which honestly looks like it has the more massive vertebrae (especially the vertebral centra)?

How do the elephant’s tusks compare to Triceratops’ horns? Farlow (1990) found that the basal area of Triceratops horn cores were as thick relative to total body mass as the tusks of elephants, but also noted how bone and ivory probably differ in mechanical properties, how Triceratops horns would be further strengthened by a keratin sheath (unlike elephant tusks), and how the inner cavities of horns and tusks are not the same.

But Farlow also compared large ceratopsian brow horns (particularly those of Triceratops, Anchiceratops, and Pentaceratops) to the horns of antelope and the tusks of proboscideans, particularly by plotting horn or tusk basal area against length (or reach). Lo and behold, while proboscidean tusks continue the trend seen in antelope, Triceratops and other ceratopsid brow horns plot well above this trend. This means Triceratops brow horns were thicker for their length (read: more robust) than the tusks of an elephant. While the horn cores of Triceratops do plot as being somewhat shorter in absolute terms than the tusks of an elephant with similar basal area, the horn cores would have been covered in a keratinous sheath in life, making them both longer and thicker. So a Triceratops would enjoy the benefits of having more stronger and more robust horns while still retaining similar length/reach to the tusks of an elephant.


From Farlow (1990) hyperlinked above.

All ceratopsids had skulls with bony secondary skull roofs, with sinuses that made a negligible impact on total skull mass (Farke, 2010). By contrast, both rhino and skulls are extensively pneumatic (rhino->, elephant->), which definitely has an impact on total skull mass, and I'm pretty certain they don't have secondary skull roofs. So a ceratopsid would have a more strongly reinforced, and overall more massive skull than a similar sized rhinoceros and elephant. Don't believe me? An average adult male bush elephant (weighing 6 tonnes) had a cranium that weighed ~188 kg (Byers & Ugan, 2005). By comparison, Triceratops prorsus specimen YPM 1822 was estimated to have a total skull mass of ~220 kg (Farke, 2006). And this particular Trike wasn't even a particularly big specimen either, with a skull length of only 1.6 meters (Longrich & Field, 2012) (Triceratops can easily have skulls 2.4-2.7 meters in length).

To help lift this massive head and strengthening the neck, the first three cervicals of ceratopsids were fused together to form a single bone called the syncervical (below is that of Chasmosaurus russelli).



This is obviously not the case with elephants



or rhinos.



Lastly, with regards to axial anatomy, ceratopsids like Triceratops had a single, nearly perfectly spherical occipital condyle connecting their skulls to the atlas. Because it was placed at the natural balancing point of the massive head, it would have allowed Triceratops to rapidly swerve its head (using the powerful neck muscles) at any direction with great precision. This would allow it to make more rapid reactions to a predator attacking it head-on. T. rex trying to reach inward to grab the neck? Rapid swerve to the head counters that. Of course, an elephant's two occipital condyles aren't shaped this way->, and an elephant cannot move its head very far to the sides (Haynes, 1993->); the bush elephant will have a much harder time countering this way than a Triceratops can.


From Bakker (1986), as mentioned in the very beginning of this post.

Physical body protection:

Finally, a Triceratops would have had certain parts of its body protected better than in either an elephant or rhino. Obviously there's the thick neck frill, which in Triceratops was solid bone. But also, according to Greg Paul, its abdomen would have been well-protected too.

The posterior ribs of ceratopsids were tightly packed together and articulated with the prepubis (Paul and Christiansen 2000), forming a cuirass that provided protection to the abdomen.

Source: Tyrannosaurus rex: The Tyrant King (Chapter 18, p. 331).

(The third to last picture I posted above contains a visual of this as well)

[Infinity Blade]

Alright, so I've revised how I view this fight over the years so many times, it's not even funny. I'm sure theropod will remember the tyrannosaur versus elephant discussion I had with him on DeviantArt just a couple years back.

Tell me what you think of my long assessment I've tried to perfect over the years. Reasonable?

Changed to the extant African bush elephant for simplicity's sake.

At parity, I favor the Tyrannosaurus, no question. Mammalian megaherbivores like elephants (and rhinoceroses and hippopotamuses) may do just fine against contemporary predators that weigh at least an order of magnitude less than them. But Tyrannosaurus was a colossal predator every bit as massive and powerful as its foe presented here; it is a whole different ball game.

At first glance, one might think it difficult to see how Tyrannosaurus could deal with the elephant's tusks unless it could run circles around the proboscidean. In fact, a common thing I remember reading in Tyrannosaurus vs. Triceratops discussions is "I can't really see how Tyrannosaurus will get past the horns", or something like that; one might think the same here. And sometimes, elephants develop these really long, impressive-looking tusks; their intimidating size might make someone think the tyrannosaur will have to get past them.

In reality, I don't think tusks or horns are anywhere near as big of an obstacle to Tyrannosaurus' victory against such animals as people make them out to be. All the Tyrannosaurus really needs to do is grab the elephant somewhere by the head, face, or neck with its oversized head and jaws, and once that happens it's free to do whatever it pleases. I can definitely envision it landing that bite too without getting gored. After all, an adult Tyrannosaurus would have well over 5 meters of skull, neck, and torso providing it substantial reach from where it's standing; in a ~7t T. rex, that would be 5.41 meters of reach->. Even if we assumed the bull elephant had exceptional record-sized tusks that were 3.51 meters long (Raubenheimer et al., 1998) - which I think would be too long to be very good weapons, more on that down below - , the T. rex would have a substantial reach advantage over it (when you consider that the elephant's face and head are themselves viable targets, then the elephant's reach could be boiled down to the length of its tusks). And average tusk length for bush elephants is far shorter than this. Moderately lengthed tusks - the only tusk size that is really going to do an elephant good in a fight* - are certainly not going to provide much of a reach advantage/barrier to the tyrannosaur for it to grab the elephant's anterior region. And if the tusks really must be dealt with, fossil evidence (namely that with Triceratops) has shown that Tyrannosaurus sometimes bit onto the goring weapons of its prey to either defend itself from injury or to handicap its quarry. Therefore, it's not unreasonable to think that a Tyrannosaurus could bite onto a tusk with its jaws and wind up breaking it with the enormous power of its jaws, neck, or whole body for that matter, whether it's on the offensive or defensive and whether it breaks the tusk deliberately or not.

*Wait, what's wrong with really long, record-sized tusks? For one, with their prodigious length also comes greater fragility, unless these tusks are also correspondingly much thicker to retain even the same strength; an elastically similar structure that is doubled in length needs to be nearly three (2.83) times thicker to have the same bending strength (Paul, 1988). Unfortunately, while elephant tusks do grow thicker with increasing length, they do not grow sufficiently thicker to the point where they retain the same bending resistance (Chiyo et al., 2015). Also, longer tusks=inferior leverage. Elephants gore via one of two ways. One way is that they use their weight to press their tusks down on a grounded or smaller opponent that's low to the ground; this is a great way of puncturing something with your tusks, but the elephant obviously can't do this to a standing T. rex. Alternatively, they perform dorsiflexion of the head that creates an upwards stabbing motion with the tusks. This means that when a very long-tusked elephant raises its head to stab upwards, there's a longer way between the tip of the tusks and the fulcrum (basically the elephant's neck); consequently, as per basic physics, more force is lost by the time you get to the tip of the tusks than with shorter tusks. What good are long tusks if the elephant finds difficulty in getting those to penetrate deeply?

In one respect this fight is similar to a great white versus a walrus. A white shark's big, wide mouth is full of serrated teeth, allowing it to bite out a massive bolus of skin, flesh, and blubber. It's a horrific weapon, and one I find capable of much worse damage output than a walrus' tusks, as damaging as the latter are. Similarly, I favor the tyrannosaur's weapon between the two main weapons of their respective owners (mouth and tusks) for two key reasons:

1.) While getting a hole pierced through you with a horn or tusk sucks, tearing/gouging/cutting out a chunk of skin, meat, or even bone, with the enormous mouth and teeth Tyrannosaurus had would create a gaping wound much greater in depth and width than one created by an elephant's tusk, and probably similar in length to one (unless an elephant with extremely long tusks ever actually manages to get all whatever meters of tusk in, and I'm not sure how likely that is). Looking at images of goring wounds by elephants and gaping wounds caused by shark bites, I find the latter to be much worse (at least relatively, except Tyrannosaurus is bigger than any living shark). Now, sure, Tyrannosaurus' teeth may not have been as specialized for slicing flesh as those of sharks or very distantly related theropods, so it would not have been able to cause this kind of damage as economically, but that won't stop massive soft tissue damage and blood loss from coming around. And of course, while not as efficient at slicing through flesh, Tyrannosaurus would be more efficient at damaging bone.

2.) This also assumes the elephant's tusks do manage to inflict fatal damage. Make no mistake, I'm not saying they'll be unable to, just that they won't necessarily do so invariably. There are instances where even when animals with goring weapons do stab other, similar sized animals, they fail to seriously debilitate them or puncture through their bodies (rhino stabbing rhino->, rhino stabbing rhino 2->, third account of rhino stabbing rhino but the video is unfortunately no longer available->, rhino stabbing buffalo->, mother gazelle stabbing baboon->). And even when they do they still sometimes fail to kill, and when they do kill, it may not be until long after the fight ended (buffalo stabbed by rhino doesn't die until the next day->). Whether or not they kill something of similar size is, of course, contingent on variables including where they stab it, how much force they manage to generate behind the thrust in that instance, and how much the other, constantly moving animal moves in the direction of the force of the stab (i.e. if you're moving the same direction the same moment you're stabbed, you minimize how much it penetrates into you). This is less of a problem for the teeth of a tyrannosaur, as it's two opposing planes of force (the upper and lower jaws), as opposed to one (the elephant driving its tusks) coming together that make the teeth (each outfitted with two serrated cutting edges that aid in piercing) penetrate.

• Less important but perhaps something to keep in mind: elephant tusks can break during combat or even during more mundane foraging activities, and this apparently isn't uncommon (Chelliah & Sukumar, 2013; Poole, 1989; link 1, link 2). In fact, it's apparently the least aggressive bulls that tend to grow the largest tusks; they're less likely to break them in a violent fight, allowing them to grow to such great length (link). This may not be too surprising, as elephant ivory actually has poor tensile strength (Chelliah & Sukumar, 2013). Now listen, I'm not arguing that elephant tusks are therefore incapable of causing damage to hard, durable material, I know that they can->. Nor am I saying that the elephant tusks will shatter every time they're used for literally anything. But this doesn't change the fact that elephant tusks sometimes break under less extreme circumstances and that the material they are made of is quite limited in strength. This will inherently limit the amount of force with which they can stab, and therefore whether or not they pierce through.

One last point I want to make: I think it's quite telling that in physical confrontations between bull elephants, tusk possession is overridden by body size and musth (although musth can win a fight without there even being any tactile contact). It's only when these two parameters are equal that elephants with tusks clearly have the advantage, which isn't a big shocker (Chelliah & Sukumar, 2013). Although an elephant with good goring tusks isn't quite as reliant on size for defense as some similarly large but arguably inferiorly armed animals, it still kind of feels like elephants will rely more on sheer size than sheer weaponry.

So at similar weights Tyrannosaurus clearly wins. It's got:

• Better weapons; there's reason to think its pedal claws could also have been used against prey animals/enemies in certain circumstances, but they won't even be necessary in this fight.
  
• Superior reach; a T. rex could easily have well over 5, possibly ~6, meters of torso, flexible neck, and skull cantilevered right in front of where it's standing. The longest African bush elephant tusks are ~3m IIRC, while average ones are surely much shorter.
• It could probably subdue the elephant, considering the fossil record shows evidence of tyrannosaurids using an attack strategy to literally bring down ceratopsids to feed upon them (I made a post about this). And it seems pretty clear that ceratopsids are much more powerful animals than elephantids at parity (you'd probably need some of the most robust proboscideans, like a mastodon, to match them).
• The luxury of fighting a foe whose best weapon is arguably its size, tusks notwithstanding.