Another weird ankylosaur from Gondwana: Stegouros elengassen

[Smilodon P.]

I saw an image some days ago, but only now I found the paper about this flat-tail armored guy (or girl) from Chile:

https://www.nature.com/articles/s41586-021-04147-1]

[Newt]

Well that's just fantastic! The tail made me think of this:

[Gothmog the Baryonyx]

It's still only an informal name, it hasn't been peer reviewed and published yet

[Faelrin]

Wow that has some exceptional remains there. I can't think of too many ankylosaurs like this, other then like Zuul off hand. Maybe Pinacosaurus too.

The tail is an incredible find and really helps diversify the group further. I hope this can receive a formal name soon, and I hope to see a figure of it in the future (wouldn't surprise me if CollectA jumped on it, with how quick they are with new taxa).

[Gothmog the Baryonyx]

In other news, on the same day this was announced a new dinosaur that has actually been published, a Velocoraptorine Dromaeosaurid from Central Mongolia, Kurri kulla, has actually been named also:

https://digitallibrary.amnh.org/handle/2246/7286

[stargatedalek]

Interesting note, it's not an Ankylosaur! It's a group that split off earlier than Nodosaurs and then evolved tail clubs convergently. And it brings Minmi with it into this new group.

[Gothmog the Baryonyx]

Very interesting but I hope they come up with a different name when it is formally named and described.

[Sim]

In other news, on the same day this was announced a new dinosaur that has actually been published, a Velocoraptorine Dromaeosaurid from Central Mongolia, Kurri kulla, has actually been named also:

https://digitallibrary.amnh.org/handle/2246/7286

Its name is actually Kuru kulla, which is a bad name choice as 1. there's a disease called kuru and 2. the name is basically the name of a deity split in two.  I find it just plain weird to make a name that only works when both the genus and species are put together.  What if you need to name a new species in that genus?  This stupid type of name has already been used at least twice for dromaeosaurids, earlier this year with Shri devi and earlier with Tsaagan mangas.  I wish people would just stop with these rubbish names.

Interesting note, it's not an Ankylosaur! It's a group that split off earlier than Nodosaurs and then evolved tail clubs convergently. And it brings Minmi with it into this new group.

"Ankylosaur" is a bit of a confusing term as it could mean ankylosaurian or ankylosaurid.  The paper finds Stegouros to be an ankylosaurian but not an ankylosaurid.  There's no mention of Minmi, but Kunbarrasaurus and Antarctopelta are suggested to be in a new group together with Stegouros.

[Newt]

"Kuru" is also a brand of shoes.  I know because my better half got me a pair. "Oh boy!" I thought. "Spongiform encephalopathy for my feet!" But "Thanks, darling!" is what I said, because I know which side my bread is buttered on.


They are very comfortable shoes, I must say. Just a shame they didn't pick a more savory name than one taken by a brain-destroying prion-induced illness spread by the practice of eating raw human brains. Either the marketing folks didn't do their due diligence (I hope I'm using that term correctly) before selecting the brand name, or they did and said, "That's an association we'll proudly own!". Much like Tom Petty, I can't decide which is worse.


Vaguely back on topic: I'm fascinated by dinosaur biogeography, but darn if new discoveries don't keep throwing wrenches (or spanners, for my transatlantic friends) into my understanding. I just read a couple of abstracts today that indicated that the Cretaceous "sauropod hiatus" in North America may be entirely artifactual; one mentioned in passing that the Campanian Cerro del Pueblo formation of Coahuila has undescribed titanosaur remains, and the other indicated that wide-gauge titanosaurs were known almost entirely from upland environments, which is a problem for the sauropod hiatus because (A) wide-gauge titanosaurs were pretty much the only sauropods left by that time and (2) upland environments are desperately undersampled for that period in North America. Next they'll take the Oligo-Miocene Cat Gap away from me! Anyway, the idea that not only were ankylosaurians present in Gondwana but that they had an endemic radiation is powerful stuff for someone raised on the Dinopedia.

[Gothmog the Baryonyx]

Stegauros has now finally been published. It was leaked early by someone of dubious repute.
Pity about the name, but it's a very interesting discovery. That tail, though probably an evolutionary dead end, marks this as a unique animal, and one of the best of the year.

@Sim I actually like it when the genus name and species name combine to make a phrase. Its like a low key puzzle. If they ever name a second species the challenge is to make a new phrase.

[Shonisaurus]

I hope Collecta, PNSO, Safari or another brand of toy dinosaurs will make that rare ankylosaur from Patagonia with an Aztec-type mace. It will be for me one of my requests for the next year 2022 to encourage a company of dinosaurs to be encouraged to do so. I wish a figure of that stegourus and the parrosaurus missouriensis.

[Carnoking]

This thing is incredible!

[Brontozaurus]

Vaguely back on topic: I'm fascinated by dinosaur biogeography, but darn if new discoveries don't keep throwing wrenches (or spanners, for my transatlantic friends) into my understanding. I just read a couple of abstracts today that indicated that the Cretaceous "sauropod hiatus" in North America may be entirely artifactual; one mentioned in passing that the Campanian Cerro del Pueblo formation of Coahuila has undescribed titanosaur remains, and the other indicated that wide-gauge titanosaurs were known almost entirely from upland environments, which is a problem for the sauropod hiatus because (A) wide-gauge titanosaurs were pretty much the only sauropods left by that time and (2) upland environments are desperately undersampled for that period in North America. Next they'll take the Oligo-Miocene Cat Gap away from me! Anyway, the idea that not only were ankylosaurians present in Gondwana but that they had an endemic radiation is powerful stuff for someone raised on the Dinopedia.

It's honestly so exciting to speculate what Gondwanan ankylosaurs were like now that we have Stegorous. We're so familiar with the big Asian and American forms with their tail clubs that these smaller forms with bladed tails must have been up to something totally different.

[Newt]

It's honestly so exciting to speculate what Gondwanan ankylosaurs were like now that we have Stegorous. We're so familiar with the big Asian and American forms with their tail clubs that these smaller forms with bladed tails must have been up to something totally different.

Maybe abelisaur shins were more susceptible to chopping than to smashing.


Seriously though, I think you're onto something with the size difference. Tail clubs are only found on big animals - ankylosaurids, a couple of weirdo sauropods, Deodicurus, possibly some meiolaniid turtles...am I missing any? They don't seem to scale down, which makes sense, since they're all about momentum and therefore mass. Animals below a certain size threshold just can't support a club that would be an effective bone-breaker, even against similarly small foes. Smaller animals are better off with pointy weapons.

[Concavenator]

What a great discovery, easily one of my favorites from 2021.

Interesting note, it's not an Ankylosaur! It's a group that split off earlier than Nodosaurs and then evolved tail clubs convergently. And it brings Minmi with it into this new group.

Where did you see that Minmi is now grouped together with Stegouros? In the paper, its sister taxon is Antarctopelta, though as @Sim said, Kunbarrasaurus has joined this new proposed group (which the authors have called Parankylosauria). So I guess that Minmi is still considered to be an ankylosaurid.