Therizinosaurus’ claws were useless against predators

[suspsy]

What's that, you say? Dominion got yet another thing completely wrong?

According to this study, yes.

https://www.nature.com/articles/s42003-023-04552-4

Our study sampled their sister lineage Alvarezsauroidea widely, as well as ancestral forms (e.g., Allosaurus and Guanlong) and mammalian unguals for comparison (Fig. 3), and the unguals of Therizinosaurus retain the worst performance. Our FSA failed to support any previous functional assumptions requiring considerable stress-bearing, including digging earth45,46, gripping and ripping branches44, attacking prey or predators12,44 and even climbing tress47. Hence, the FSA results instead suggest functions rarely requiring stress-bearing, such as exhibition, intimidation12 or sexual display19, or as a result of sexual selection and allometry such as in the giant antlers of Megaloceros giganteus24.

[TheCambrianCrusader]

Not really surprised their claws would be display structures but still good to know nonetheless

[Blade-of-the-Moon]

lol I think just about every paleoartist has shown them as weapons at one point or the other, can't blame JW for using that..besides it's genetically engineered beast based on the current thinking at the time. That one at least, probably did use them for weapons.    I recall in Raptor Red, Bakker used his as a digger/tunneler and it even fought the Utahraptors with them..but I digress.


I don't know about useless either, they could be for intimidation? A false bluff.

 

[Leyster]

@Blade-of-the-Moon the one which appeared in Raptor Red is an hypotetical "segnosaur" (afaik North American Therizinosaurs were still unknown when it was written), from an age when they were a still not well understood group. And note that this result applies only to Therizinosaurus, other therizinosaur claws have different functions (other species' performed well as hook-and-pull tools).

[GojiraGuy1954]

Because every exaggerated feature on an extinct animal must be a display structure. God forbid we discuss any other potential uses, it's either for fighting or an ornament

[Blade-of-the-Moon]

@Blade-of-the-Moon the one which appeared in Raptor Red is an hypotetical "segnosaur" (afaik North American Therizinosaurs were still unknown when it was written), from an age when they were a still not well understood group. And note that this result applies only to Therizinosaurus, other therizinosaur claws have different functions (other species' performed well as hook-and-pull tools).

You may be right, I need to read it again.Things  I read anymore tend to get buried in my brain after awhile. lol

Science is always learning and changing anyway, what makes sense one day is proven wrong the next. Toys, movies, books, they just can't keep up if they tried too.

[Sim]

I'm not convinced.  How else would Therizinosaurus defend itself from Tarbosaurus?  Plus, the claws of the PNSO Therizinosaurus are small and made of plastic yet they still broke my skin when I was handling it.  I imagine the claws of a real Therizinosaurus, that are much bigger and harder, would do damage when used.

[Cretaceous Crab]

Yeah, we know the claws weren't made of adamantium, but come on...they were like, 3 feet long.

If a Tarbosaurus came up on a Therizinosaurus, who started waving those bad boys around and making slashing gestures, I'm certain it wouldn't risk getting an eye gouged out unless it was really hungry.

If some predators can easily be deterred by the incessant honking and wing flapping of a goose, I bet a Therizinosaur going through the same general motions would be an intimidating defense display.

Now if it was MORE than one Tarbo, then the Therizinosaur may be out of luck on that one.

[andrewsaurus rex]

Because every exaggerated feature on an extinct animal must be a display structure. God forbid we discuss any other potential uses, it's either for fighting or an ornament

yeah it seems like every spectacular feature on a dinosaur is being dumbed down to a display feature these days.  Sort of the opposite of the 80's and 90's when dinosaurs were getting faster, bigger and more ferocious and capable every day.  Ceratopsian horns, stegosaur spikes and plates, ankylosaur tail clubs etc and now therizinosaur claws.  All nearly useless and just used for display.  I'm very skeptical.  There are easier and simpler display features that an animal can evolve.  If the claws were of no practical use, they would certainly be in the way of even basic foraging.....strange thing to evolve from selective pressures.   On most modern animals, even if something evolved for display or intra specific combat, such as antelope horns, they are still used as weapons..  Even human hands, which didn't evolve as weapons of any kind can be deadly....ask any boxer or mma star.

[suspsy]

I don't recall anyone claiming that ankylosaur clubs and stegosaur spikes and ceratopsian horns were only used for display. Whoever said that? Citation?

[Cretaceous Crab]

I don't recall anyone claiming that ankylosaur clubs and stegosaur spikes and ceratopsian horns were only used for display. Whoever said that? Citation?

Ditto. There is evidence that thagomizers (stego tails) were for defense [injuries to Allosaurus vertebrae] and ceratopsian horns in intraspecies combat.

And if there was any claim that ankylo tail clubs were only for display, I'm not buying. That's a lot of weight to haul just to look good.

Also keep in mind that structures and features can and often do play multiple roles in nature.

[Thialfi]

The study does seem to indicate that for earlier branching therizinosaurians, their claws may indeed have one or several of the functions mentioned; it's just that Therizinosaurus proper grew so large, and thus its unguals, that they basically became useless in the functions described, and with their increased length also decreasing the amount of stress those unguals could handle. 

The study does however imply the claws could have been used to deter predators - just not by slashing or stabbing them, but mainly through intimidation and the risk of losing an eye. This sounds fair and plausible.

[Thialfi]

I don't recall anyone claiming that ankylosaur clubs and stegosaur spikes and ceratopsian horns were only used for display. Whoever said that? Citation?

Ditto. There is evidence that thagomizers (stego tails) were for defense [injuries to Allosaurus vertebrae] and ceratopsian horns in intraspecies combat.

And if there was any claim that ankylo tail clubs were only for display, I'm not buying. That's a lot of weight to haul just to look good.

Also keep in mind that structures and features can and often do play multiple roles in nature.

Isn't there even fossil evidence of ankylosaur clubs breaking bones of carnivorous theropods? The infamous crurivastator part in Zuul's name?

[andrewsaurus rex]

I don't recall anyone claiming that ankylosaur clubs and stegosaur spikes and ceratopsian horns were only used for display. Whoever said that? Citation?

sorry, I didn't realize I was going for a doctorate here.    I've heard several times and seen discussions on here about dinosaur features that were once thought weapons, now being considered as evolving for mating purposes (eg display, intraspecific combat).  Ceratopsian horns I've read this about the most.

i'll look for citations when I have more time.  Here's one I found after a 5 second google search.  https://www.earth.com/news/triceratops-horns-attract-mates/   Haven't read the article just skimmed it.  The main argument for ceratopsian horns is that most were not strong and not angled well or long enough to be useful for defense.  To be clear, I don't believe it at all.

For anykylosaurs, iirc the tail clubs and armor are considered more for intra specific combat, than defense, which I considered ridiculous.   Stegosaurs it may have just been plates that were for display, not the spikes.....i'll do some digging later when I have time.

My point was that the trend these days seems to be to dumb down dinosaur abilities, rather than, like in the dinosaur heresy days,  when they were ever stronger, bigger, faster and more deadly.  Seems to be a fad to undo much of that and in the process go from one extreme to the other.

[Faelrin]

@Thialfi If I recall correctly the Zuul paper from last year said the tail club was primarily used for intraspecific combat and not defensive purposes. Although the abstract does mention it might or could still be used for such.

https://royalsocietypublishing.org/doi/10.1098/rsbl.2022.0404

[suspsy]

I don't recall anyone claiming that ankylosaur clubs and stegosaur spikes and ceratopsian horns were only used for display. Whoever said that? Citation?

sorry, I didn't realize I was going for a doctorate here.

There's nothing at all unreasonable about requesting a citation for a claim.

Here's one I found after a 5 second google search.  https://www.earth.com/news/triceratops-horns-attract-mates/  Haven't read the article just skimmed it.

And you would be well advised to read material thoroughly before citing it. This Earth article does a rather shabby job of summarizing the 2018 Knapp study, which does not eliminate predator defence as one of the uses for the horns; it simply argues that the primary purpose of the horns was rooted in sexual selection. They could still have been used for defence against tyrannosaurs when necessary. Especially in Triceratops.

For anykylosaurs, iirc the tail clubs and armor are considered more for intra specific combat, than defense, which I considered ridiculous. 

Why would intraspecific combat be ridiculous? There is direct fossil evidence for this behaviour in the form of healed armour damage in Zuul. Similarly, there is direct fossil evidence that Stegosaurus used its tail against Allosaurus. Again, just because ankylosaurs and stegosaurs used their tails against each other doesn't mean they didn't also use them against theropods. Elephants, rhinos, hippos,  bovids, and walruses use their tusks, teeth, and horns in intraspecific combat far more often than they use them for protection against predators, but they still use them for the latter purpose regardless.

My point was that the trend these days seems to be to dumb down dinosaur abilities, rather than, like in the dinosaur heresy days,  when they were ever stronger, bigger, faster and more deadly.  Seems to be a fad to undo much of that and in the process go from one extreme to the other.

How is showing that horns and spikes and clubs could serve more than just one purpose "dumbing down"?

[andrewsaurus rex]

turns out I have more time right now than I thought.

Here's info on ankylosaur tail clubs not being defensive weapons, again after a 5 second search, so there may be better sources with digging: https://arstechnica.com/science/2022/12/ankylosaurs-tails-may-have-been-the-original-cretaceous-fight-clubs/

this blog just indicates that there is some debate about the function of stegosaur tail spikes; I know I've read arguments that state they were not for defense; https://blog.everythingdinosaur.com/blog/_archives/2007/10/14/3289552.html

In my mind, if it looks like a weapon it was probably used as a weapon, even if that was not its original reason for evolving..   I believe ankylosaur tail clubs were used as the cudgel they appear to be, and that stegosaur spikes and certopsian horns were dangerous weapons in defense against predators...

[andrewsaurus rex]

suspsy: in my opinion asking for citations is a bit ridiculous on a dinosaur toy forum.  And I did say I hadn't read the article, so I wasn't sure if it was a good citation or not.

[Thialfi]

@Thialfi If I recall correctly the Zuul paper from last year said the tail club was primarily used for intraspecific combat and not defensive purposes. Although the abstract does mention it might or could still be used for such.

https://royalsocietypublishing.org/doi/10.1098/rsbl.2022.0404

Interesting read! I can't remember if it was Zuul specifically who was responsible for said shin splinting and I can't immediately find a source for my claim either. But this paper sheds some light on that. Thanks!

[suspsy]

suspsy: in my opinion asking for citations is a bit ridiculous on a dinosaur toy forum.

It's not the least bit ridiculous, actually. If you're going to make any kind of claim regarding dinosaurs or another science topic, then you should absolutely be willing and prepared to back it up with evidence. Doesn't matter where or when. Because that's how science works.

And I did say I hadn't read the article, so I wasn't sure if it was a good citation or not.

Then frankly, you shouldn't have shared it in the first place.

Similarly, the article about Zuul you shared above clearly states that ankylosaurs could have used their clubs both for intraspecific combat and defence against predators:

"We're not seeing anything that we can quantify that suggests that predators are influencing the evolution of tail clubs. It doesn't mean that they didn't," Arbour clarified, "but we just don't have any evidence in the fossil record."

But the fossil record does show that nodosaurs, which didn't have tail clubs at all, coexisted with a number of carnivorous theropods. Other ankylosaurs lived among these predators for millions of years before their tail clubs evolved in these lineages.

I mentioned elephants, rhinos, hippos, bovids, and walruses earlier. None of those mammals evolved big tusks and horns and teeth as defences against predators. They all function primarily for intraspecific combat and sexual display. And it doesn't at all mean that they can't be used against predators if necessary. The same probably goes for marginocephalians and thyreophorans.