Mammalian carnivores vs predatory dinosaurs bite lethality

[dinosauria101]

So, in your opinion, which group of predators has deadlier bites and why?
In my opinion the predatory dinosaurs take the cake by far - they have proportionately MUCH larger heads as a whole, in addition to carinae and serrations on their teeth - even bone crushing theropods like tyrannosaurids and abelisaurids have serrations while mammalian carnivores lack them entirely - as well as no need for precision biting.

[Infinity Blade]

I probably would rate the bites of some predatory dinosaurs over those of some predatory mammals even on a "lb for lb" basis...but I don't want to overgeneralize.

There are mammalian predators that had or have serrations on their canines. Many (don't know if all) sabertooths had them* and Verdugo once posted information about how sun bears sometimes (frequently so, in fact) have serrations on their posterior carina->. Now yeah, two serrated cutting edges are still better than one, but mammalian predators can get really nasty teeth. If you were to ask me what I thought was a deadlier weapon between say, the jaws of a Deinonychus and the jaws of Smilodon gracilis (assuming the two really could weigh the same), I'd be hesitant to pick the former over the mouth with enormous fangs that not only have at least some kind of serrations on them, but could puncture through skulls.

*Although, at least in the case of Smilodon (and presumably other machairodonts?), these teeth were not truly ziphodont. The carinae were composed only of enamel->, unlike the serrations seen in other animals. I also feel that they don't look like they'd cut as well as other predatory animals' tooth serrations, but I could be wrong.

[dinosauria101]

Ah, sun bears have serrations? Interesting!
I did know about the sabertooths, but there was a researchgate atricle comparing Gorgosaurus and Komodo dragon serrations (you may know what I am talking about) that said they were not true serrations.
As for your example, Deinonychus IS larger at 111 kg as opposed to 55-95 kg, but we can get what is for all intensive purposes parity with that specimen of Deino (YPM 5210, which the 80 kg estimate was based on) for a good comparison. Nevertheless, I'd be cautious of labeling the Smilodon's bite superior overall, for while it is better at skull damage and can certainly cause rib damage as we have seen, it seems a lot more of an awkward weapon by its very nature, which is also probably too different for a good analoguy between the 2. Maybe a more apples to apples comparison would be short faced bear and Afrovenator; they're around the same weight IIRC

[Infinity Blade]

but there was a researchgate atricle comparing Gorgosaurus and Komodo dragon serrations (you may know what I am talking about) that said they were not true serrations.

I'm actually not entirely sure what you're referring to, show it to me.

[dinosauria101]

Nov 15, 2019 18:49:27 GMT 5 Infinity Blade said:

but there was a researchgate atricle comparing Gorgosaurus and Komodo dragon serrations (you may know what I am talking about) that said they were not true serrations.

I'm actually not entirely sure what you're referring to, show it to me.

Here it is: www.nature.com/articles/srep12338

Looks like you were right earlier. Enamel carina-like structures with no denticles is not true serrations 

[Infinity Blade]

That's one of the exact same papers I linked to.

[dinosauria101]

Why so it is. My bad.

Anyhow, regarding direct apples to apples comparison, one of the best I can think of would have to be Pachycrocuta and Deinonychus; the weights are close at 108 vs 111 kg and neither needs to rely on precision to bite. In that case, I'd take Deinonychus' bite as not only is its head significantly larger (41 cm vs 28-30 cm), it has a very carcharodontosaurid-like bite mechanism which is to say a pretty simple one - no need for force, relies on serrations and pretty much equal throughout the mouth. Whereas Pachycrocuta needs to rely on crushing power from the very back of its mouth (hard to infict a bite from there on a foe that's fighting back) and its bite at the canines, which is the easiest to land, is not gonna do all that much.

[Verdugo]

The thread is far too broad tbh but i assumed you probably want a Best vs Best comparison. The thing is i already talked about this before. You really cannot say this animal has better bite than that animal based solely on a few factors like skull length or serrations. You need to look at the entire killing apparatus animal as a whole. Some factors that you might want to consider (not inclusive):

1. Bite force (Duh!)
2. Bite size and Gape (which is related to Skull length that you're alluding to)
3. Teeth size, teeth design, teeth position in the jaw. For example, like comparing T-rex or Hyenas to Crocodiles. These animals are usually considered as 'bone crushers' due to their high Bite force. However, when you look at their teeth, it's clearly they're not doing the same thing.
4. Cranial and mandible geometry. For instance, T-rex lower jaw fits into its upper jaw. This allows it to enhance bone-cracking capabilities by taking advantage of Shear stress (imagine T-rex jaw like a scissor that helps it Shear though bones)
5. Post cranial forces, usually from neck muscles and the rest of the animal. I already posted the use of post-cranial forces in Hyena which allows them to enhance their bite potency. And you can also see that in Ora how they used their post-cranial forces to help them compensate for their very weak Bite force. 

There are probably even more to this but i just haven't thought of yet. Anyway, you can look at the Grizzly bear for example. They don't have a lot of stand-out traits when it come to their bites. Bite force is not exceptionally strong for Carnivorans of its size, Canines are not enlarged like Felids, skulls are not disproportionally big. However, their neck muscles are massive and their skull are stronger than other Bears (thanks to their pneumatised high-domed skull). And thus, they are very good as using their post-cranial forces to bite, pull-back, and shake their preys. Here is the result (warning graphic):

www.youtube.com/watch?v=QfYVez5qiIk
^ At 1:07

Also, see how the Hyena here used its strong neck muscles, strong Bite force and robust Canine teeth to grip and pull the Wildebeest down. Then it started using it strong but flexible neck and carnassial teeth to dismember its prey. And you can see just fast and efficient the Hyena is at tearing its prey apart with this technique. Graphic, duh.


www.youtube.com/watch?v=E0kNW4KQCoY&t=

When it comes to Best vs Best, i wouldn't bet on even a T-rex against the best biter of Mammals (on lb 4 lb basis of course). I made a post on Megistotherium and Simbakubwa's biting apparatus (link 1; link 2). The skull size alone is comparable in width and length to an exceptionally large Saltie (something in the 900 kg weight class) and these Hyaenodontids are like around 500-600 kg. The biting prowess is clearly in no way inferior to any Theropods (lb 4 lb).

I have also posted some stuffs on Dinocrocuta on Wildfact that you already seen. I mean, visually, its skull and teeth are built like monsters. The skull of Dinocrocuta is about 305 mm in width (source, Table 1) which is actually comparable to the 332 mm skull width of Majungasaurus (source, Table 2). The skull on the other hand is much shorter and the mandible is akinetic. These mean that the Mammal here probably has stronger Bite force. And the Dinocrocuta is like what, 200-250 kg compared to a 1 tonne Theropod. How is it in anyway inferior?

[dinosauria101]

I was referring to as a whole and usefulness in a head on fight. There are definitely exceptions to the rule.

[Infinity Blade]

Yeah, in the first line of my first post I was talking something like say, a tyrannosaurid, carcharodontosaurid, megalosaurid, ceratosaurid, or an allosaurid versus a wolf, conical-toothed cat, bear, maybe even a spotted hyena “lb for lb”. Hyaenodontids seem to be something else (a hyaenodontid and a theropod like the ones above arguably have their own advantages, proportionately of course).

[dinosauria101]

Well, hyaenodontids are not carnivorans. SO yeah it's a bit like apples to oranges.

[Infinity Blade]

Not as apples-to-oranges as a comparison between the jaws of animals whose last common ancestor lived ~312 million years ago. What I wrote is fine enough.

[Supercommunist]

Not a dinosaur, but does any have an idea as to how powerful an erythrosuchus bite would be?

[Infinity Blade]

I'm afraid no one's done any calculations on it, but it must have bitten damn hard for sure. The head wasn't just comically large for its size, but the snout was deep, the temporal fenestrae were large, the skull bones were robustly constructed, and the back of the skull flared out laterally, all of which you'd expect in a hard biting animal.


markwitton-com.blogspot.com/2016/09/a-salute-to-erythrosuchidae.html

[Supercommunist]

^Yeah I figured that was the case, but I wondered if maybe its head was super large because of some other function like mouth gape. But from what it sounds like it had some obvious adaptations for sheer biting power.

Proportionately speaking, how large was its head compared to a hyaenodon, an animal also mentioned to have a huge head for its size? Based on my ignorant layman opinion, I'd imagine the erythrosuchus would have an even more powerful bite than the hyaenodon and may possibly have the strongest jaws on a pound for pound basis. In general, it seems that animals that are capable of replacing their teeth are better equipped to develop more devastating bites. Unsurprisingly, high bite forces compromises the durability of teeth and mammalian carnivores already suffer from that issue. I don't think its a coincidence that most modern mammalian carnivores live less than fifteen years. I recall reading a study that most tigers by age ten suffer from severe dental disrepair, and in one instance an individual was forced to maul a person to death with its claws in order to kill them.



www.semanticscholar.org/paper/Unique-fatality-due-to-claw-injuries-in-a-tiger-a-Pathak-Dixit/2af6aed6c748942f0be85cfaa81f5a721898dca3

I imagine for similar reason, most mammals never developed serrations since those edges would probably just dull fairly quickly and make the adaptation useless since their is no way to replace them. I remember hyaenodons had a clever way of somewhat circumventing this problem but IIRC they couldn't flat out replace teeth.

Since erythrosuchus didn't really need to be worried about the durability of teeth I wouldn't be surprised if it had an significantly more powerful bite than hyaenodon.