Largest NON-TUSK teeth on land?

[Infinity Blade]

I could be misremembering, but I think I recently read a paper claiming that large theropods had the largest teeth known of any terrestrial vertebrate. Obviously this would discount tusks (e.g. proboscideans, narwhals, walruses, hippos), since if we included those, they would easily take the cake as the largest teeth in the entire animal kingdom. The largest non-tusk teeth ever, to my knowledge, are those of Livyatan melvillei and kin.

But even discounting tusks...is this claim (i.e. theropods having the largest teeth of any land vertebrate) really true? Some saber-toothed synapsid predators appear to have had or are said to have had canines as large as, if not larger, than the teeth of even the largest theropods. Below is an image you can find floating around online comparing the upper canine of a Smilodon with the tooth of a T. rex (by David Evans, from what I can find).


Barbourofelis fricki also had some immense upper canines, and it appears that the exposed portion is indeed crown (Martin, 1980).


The gorgonopsid Rubidgea is said to have had saber canines larger than those of Tyrannosaurus rex (van Valkenburgh & Jenkins, 2002). Unfortunately, I can't verify this claim since the source cited for it is an unpublished thesis.

The incisors are very large, postcanine teeth are absent, and the saber canines are huge—those of Rubidgea atrox (Fig. 4.5) are longer than the teeth of the theropod dinosaur Tyrannosaurus rex (Jenkins, 1998).

Large theropods certainly must have been contenders, though. According to Gignac & Erickson (2017), known T. rex tooth crowns are up to 18 cm in height, apparently the largest of any dinosaur.

However, extensive bite-mark evidence on herbivorous and conspecific dinosaur skeletons, heavily worn and broken teeth, and bone-bearing coprolites attributable to large (10–13 m) Albertosaurus sarcophagus, Gorgosaurus libratus, and Tyrannosaurus rex (Dinosauria: Tyrannosauridae), demonstrate that these North American taxa were exceptionally osteophagous, among theropods. All were equipped with large, stout lateral teeth (up to 18 centimetre [cm] crown length, 138 cubic centimetre [cc] volume in T. rex—the largest of any dinosaur) that regularly scored, deeply punctured, and even sliced through bones.

I think we can agree that the true record holder is probably going to be some predatory animal, as long teeth are often seen as a useful attribute for predators (especially those tackling large prey), and herbivores with long teeth tend to be tusked (which are out of this thread's question).

So let's make this question very simple. Out of all terrestrial animals, which animal had/has the largest non-tusk teeth in absolute terms?

[theropod]

Actually depends on what exactly you mean by "largest tooth". Just strictly the longest? In that case I have nothing to add to your list.

But if by largest you mean most voluminous or most massive, then elephantids probably have the largest teeth of any terrestrial animal, and are even serious contenders for the largest non-tusk teeth of any animal, period.
At least I cannot really think of much that has teeth that would even stand a chance of matching the size of some mammoth and bush elephant molars I’ve seen (and I’m talking wooly mammoth here, so not one of the truly gigantic extinct elephantids), they can easily give even Livyatan a run for its money in terms of the sheer mass of the teeth. But it seems to be surprisingly hard to find what exactly the absolute record holder is, neither do I know how much interspecific variation there is in relative tooth size, and which elephantid has the absolute biggest teeth. But even the ones I know are enormous.

Slightly related note, but what exactly even defines a tooth as a tusk? I always thought it was being exposed when the mouth is closed, but your post reminded me that hippo teeth are also often called tusks, and they fit neatly inside the oral soft tissues, so by that definition they’d be normal teeth, not tusks.

[Infinity Blade]

Oct 15, 2023 4:05:32 GMT 5 theropod said:

Actually depends on what exactly you mean by "largest tooth". Just strictly the longest? In that case I have nothing to add to your list.

But if by largest you mean most voluminous or most massive, then elephantids probably have the largest teeth of any terrestrial animal, and are even serious contenders for the largest non-tusk teeth of any animal, period.
At least I cannot really think of much that has teeth that would even stand a chance of matching the size of some mammoth and bush elephant molars I’ve seen (and I’m talking wooly mammoth here, so not one of the truly gigantic extinct elephantids), they can easily give even Livyatan a run for its money in terms of the sheer mass of the teeth. But it seems to be surprisingly hard to find what exactly the absolute record holder is, neither do I know how much interspecific variation there is in relative tooth size, and which elephantid has the absolute biggest teeth. But even the ones I know are enormous.

Slightly related note, but what exactly even defines a tooth as a tusk? I always thought it was being exposed when the mouth is closed, but your post reminded me that hippo teeth are also often called tusks, and they fit neatly inside the oral soft tissues, so by that definition they’d be normal teeth, not tusks.

Longest was primarily what I had in mind, and I was curious which land animal seems to hold the record in that regard. However, volume/mass was also something I kept in mind. The impression I got from online size comparisons was that, for instance, Livyatan teeth are significantly thicker than T. rex teeth, but maybe not necessarily longer. For the former reason alone I'd still consider Livyatan teeth to be larger.

I kind of forgot about elephants. To be honest, I wasn't entirely sure if their molars can be considered single units (i.e. a single tooth) or a battery of numerous small individual teeth. I knew they have multiple sets of teeth throughout their lives, and from a quick search online, I have the impression that they are indeed single teeth. So I guess elephant teeth are a contender for mass.

As for what makes a tusk, it's a bit complicated, but strictly speaking key factors are continuous growth, tissue composition of the tooth, and having a gomphosis (so a fibrous joint that holds the tooth in its socket) throughout the tooth's life (Whitney et al., 2021). Hippo canines grow continuously, have a tusk-like tissue composition (they have enamel, but it doesn't cover the entire surface area of the tooth. They are still covered by soft tissue when the mouth is closed, but I feel that's more due to the unique arrangement/anatomy of the oral soft tissue (i.e. the lower canines fit in "pockets" on the upper jaw) than anything else (boar tusks, for instance, are exposed when the mouth is closed, but they're not necessarily larger proportionately, especially not the tusks of Sus scrofa). All this considered, I'm not 100% positive on whether or not we can call hippo canines true tusks, but I wouldn't necessarily be opposed to it.

Here, we define a tusk based on gross morphology, continuous tissue deposition and eruption, tissue composition, and tooth attachment tissues. In using multiple characteristics to differentiate a tusk from other dental structures, it is possible to distinguish between dentitions that may have anatomical similarities, but are not developmentally homologous. The term ‘tusk’ has been widely used to describe any incisor or canine that extends out from the oral cavity [13]. Further, the term is also used in a range of dentitions where there is an enlarged tooth position but the crown does not extend out from the oral cavity such as the palatal ‘tusks’ of some extinct amphibians or the canine-like ‘tusks’ in some heterodontosaurid dinosaurs (e.g. [15,16]). However, a key developmental characteristic for a true tusk is continuous growth, allowing it to be distinguished from enlarged teeth that are morphologically similar but have determinate growth and eruption. Although vestigial deciduous teeth can be replaced early in ontogeny (e.g. the tush in elephants), a wide-open pulp cavity indicating active and continuous dentine deposition and eruption is a feature of the permanent tusk dentition [13]. Further distinguishing a tusk from other tooth types is its tissue composition. Due to the geometric constraints of producing both enamel and dentine continuously [17,18], ever-growing teeth will contain enamel, but the tissue will not cover the entirety of the dentine core as in other dentitions. In tusks, an enamel cap is present initially at eruption but is eventually worn away [12,13,19]. The result is a mature histology consisting mainly of dentine with cementum coating the root and occasionally at the point of new eruption prior to any wear [13,19]. Importantly, it is this adult tissue composition that distinguishes a tusk from ever-growing teeth such as rodent incisors or hypselodont molars where both enamel and dentine are continuously deposited [17,18,20,21]. Finally, the mode of attachment for a tusk must be ligamentous (i.e. a gomphosis) to accommodate the sustained movement of the tusk occlusally throughout life. Fusion of the tooth to the jawbone (i.e. ankylosis) precludes continuous tissue deposition and eruption. Therefore, although this mode of attachment can be found in many tooth types, it is a requirement for an ever-growing dentition. In summary, a tusk is defined and can be identified by having a combination of features: (i) a portion of the crown that extends out from the oral cavity, (ii) continuous growth and eruption, necessitating (iii) a gomphosis throughout the lifespan of the tooth and (iv) dentine as the sole tissue forming the crown.

[tyrannasorus]

Oct 15, 2023 4:05:32 GMT 5 theropod said:

Actually depends on what exactly you mean by "largest tooth". Just strictly the longest? In that case I have nothing to add to your list.

But if by largest you mean most voluminous or most massive, then elephantids probably have the largest teeth of any terrestrial animal, and are even serious contenders for the largest non-tusk teeth of any animal, period.
At least I cannot really think of much that has teeth that would even stand a chance of matching the size of some mammoth and bush elephant molars I’ve seen (and I’m talking wooly mammoth here, so not one of the truly gigantic extinct elephantids), they can easily give even Livyatan a run for its money in terms of the sheer mass of the teeth. But it seems to be surprisingly hard to find what exactly the absolute record holder is, neither do I know how much interspecific variation there is in relative tooth size, and which elephantid has the absolute biggest teeth. But even the ones I know are enormous.

Slightly related note, but what exactly even defines a tooth as a tusk? I always thought it was being exposed when the mouth is closed, but your post reminded me that hippo teeth are also often called tusks, and they fit neatly inside the oral soft tissues, so by that definition they’d be normal teeth, not tusks.

Can molars be counted as a singular tooth? A google search gives an elephant having both 12 and 4 molars, essentially an elephant will have four sets of molars in their mouth but some sources consider each one a combination of several teeth giving us 12 or more molars altogether 

[theropod]

Oct 17, 2023 11:34:00 GMT 5 tyrannasorus said:

Oct 15, 2023 4:05:32 GMT 5 theropod said:

Actually depends on what exactly you mean by "largest tooth". Just strictly the longest? In that case I have nothing to add to your list.

But if by largest you mean most voluminous or most massive, then elephantids probably have the largest teeth of any terrestrial animal, and are even serious contenders for the largest non-tusk teeth of any animal, period.
At least I cannot really think of much that has teeth that would even stand a chance of matching the size of some mammoth and bush elephant molars I’ve seen (and I’m talking wooly mammoth here, so not one of the truly gigantic extinct elephantids), they can easily give even Livyatan a run for its money in terms of the sheer mass of the teeth. But it seems to be surprisingly hard to find what exactly the absolute record holder is, neither do I know how much interspecific variation there is in relative tooth size, and which elephantid has the absolute biggest teeth. But even the ones I know are enormous.

Slightly related note, but what exactly even defines a tooth as a tusk? I always thought it was being exposed when the mouth is closed, but your post reminded me that hippo teeth are also often called tusks, and they fit neatly inside the oral soft tissues, so by that definition they’d be normal teeth, not tusks.

Can molars be counted as a singular tooth? A google search gives an elephant having both 12 and 4 molars, essentially an elephant will have four sets of molars in their mouth but some sources consider each one a combination of several teeth giving us 12 or more molars altogether 

Yes, molars are each a singular tooth. They are not dental batteries (but this is precisely why I didn't consider large hadrosaurs a contender).
the 12 molars of an elephant refer to the number it gets in total during its lifetime. However, not all of these teeth are actually present simultaneously; at any one time, an elephant has just one functioning molar per quadrant (or two halves, making a whole), which gets worn down and replaced by the molar that is anatomically and developmentally just the tooth behind it, but ontogenetically acts like it is a succeeding tooth generation.
This process is called horizontal tooth replacement, and is the reason for the discrepancy between the dental formula and the actual teeth observable in the jaw, not that several teeth somehow make up a single molar.

[duriaantiquior]

An elephant's back molar is 30cm long, so I would guess Palaeoloxodon had the largest.

[tyrannasorus]

I see, then elephants and woolly mammoths may very well have the largest and most voluminous teeth

Back on topic it still seems like Tyrannosaurus has the longest teeth on land unless we find molars of larger proboscideans that are even more massive
I’ve heard that tarbosarus Had teeth comparable in length but falls short in thickness

[duriaantiquior]

How long are T. rex's teeth?

[Infinity Blade]

Oct 17, 2023 18:22:40 GMT 5 duriaantiquior said:

How long are T. rex's teeth?

The most commonly cited figure is that they're a foot long (so 30 cm) in total. However, one paper I cited in the OP mentions T. rex tooth crowns being up to 18 cm in length, which if true, would make me think the whole tooth would be even bigger (unless it's somehow weirdly proportioned such that the root takes up less/the crown makes up more of the tooth's length than usual).

[duriaantiquior]

Oct 17, 2023 18:39:36 GMT 5 Infinity Blade said:

Oct 17, 2023 18:22:40 GMT 5 duriaantiquior said:

How long are T. rex's teeth?

The most commonly cited figure is that they're a foot long (so 30 cm) in total. However, one paper I cited in the OP mentions T. rex tooth crowns being up to 18 cm in length, which if true, would make me think the whole tooth would be even bigger (unless it's somehow weirdly proportioned such that the root takes up less/the crown makes up more of the tooth's length than usual).

This T. rex tooth is 29cm, with full crown.

bhigr.com/product/tyrannosaurus-rex-stan-tooth-29cm-11-5-in-fossil-replica/
It's also a fossil replica, so they're probably trying to make it as impressive as possible.

[Infinity Blade]

Oct 18, 2023 16:29:24 GMT 5 duriaantiquior said:

Oct 17, 2023 18:39:36 GMT 5 Infinity Blade said:

The most commonly cited figure is that they're a foot long (so 30 cm) in total. However, one paper I cited in the OP mentions T. rex tooth crowns being up to 18 cm in length, which if true, would make me think the whole tooth would be even bigger (unless it's somehow weirdly proportioned such that the root takes up less/the crown makes up more of the tooth's length than usual).

This T. rex tooth is 29cm, with full crown.

bhigr.com/product/tyrannosaurus-rex-stan-tooth-29cm-11-5-in-fossil-replica/
It's also a fossil replica, so they're probably trying to make it as impressive as possible.

Eh, these casts are based entirely off of real specimens, so I can buy the real tooth being 29 cm long. The tooth crown of a T. rex can easily be 10 cm long, and the roots of tyrannosaurid teeth are 2.5-3x the length of the crown, so yeah.

[duriaantiquior]

Oct 18, 2023 16:55:39 GMT 5 Infinity Blade said:

Oct 18, 2023 16:29:24 GMT 5 duriaantiquior said:

This T. rex tooth is 29cm, with full crown.

bhigr.com/product/tyrannosaurus-rex-stan-tooth-29cm-11-5-in-fossil-replica/
It's also a fossil replica, so they're probably trying to make it as impressive as possible.

Eh, these casts are based entirely off of real specimens, so I can buy the real tooth being 29 cm long. The tooth crown of a T. rex can easily be 10 cm long, and the roots of tyrannosaurid teeth are 2.5-3x the length of the crown, so yeah.

Well, a couple of sites sell palaeoloxodon teeth.
They are only 20cm long though.