A New Theory for Nanotyrannus??

[Fembrogon]

Recently while doing a little research, I stumbled across a paper - or, an abstract, at least - from last August, which suggests that Nanotyrannus is not synonymous with T. rex after all...
...but instead is synonymous with Dryptosaurus.

Nanotyrannus is Dryptosaurus: An Abstract. (Eleazer Brunson)

I'm not sure there's anything more to this yet (I'm not a Research Gate member so I can't tell), but the abstract discusses the possibility of dinosaurs being able to migrate between Laramidia and Appalachia; plus it mentions several skeletal features in Nanotyrannus that appear more similar to Dryptosaurus than Tyrannosaurus.

Any thoughts on this? I have no horse in the nano-t race, but I do find this notion intriguing, if only for the surprise of it.

[suspsy]

I did a little inquiring and this is what Thomas Holtz told me:

This is a self-published paper. No, the evidence presented is not very strong at all.

I suspected as much.

[Bread]

Why is this genus name still being mentioned?

I thought it was relatively set in stone that Jane was a juvenule Tyrannosaurus?

[suspsy]

Why is this genus name still being mentioned?

I thought it was relatively set in stone that Jane was a juvenule Tyrannosaurus?

I used to think so too, but lately I've been hearing rumours that that stone may well be shattered in the future. Time will tell.

[Fembrogon]

Let's be real: most things related to T. rex aren't "set in stone" even when they should be, if only because the name carries too much publicity to let issues rest.

I guess I'm not surprised this was self-published. The abstract does allude to more research coming in the future, so who knows? Maybe we'll get a peer-reviewed study with more compelling evidence (one way or the other) relatively soon.

[bmathison1972]

This is not a published paper. It is simply an abstract, possibly originally written for a meeting or symposium. It looks like they elaborated on their findings here: http://psdinosaurs.blogspot.com/2023/02/nanotyrannus-is-dryptosaurus-abstract_10.html

But don't consider this a formally published work nor should any findings in it affect current nomenclature.

EDIT: yes, what Fembrogon said above: The abstract does allude to more research coming in the future, so who knows? Maybe we'll get a peer-reviewed study with more compelling evidence (one way or the other) relatively soon.

[Dynomikegojira]

Hmm well to play's devil's advocate it certainly would explain relatively larger forearms and claws on supposed Nanotyrannus specimens but honestly not sure if those are legit since I don't really trust Peter Larson unfortunately

[suspsy]

Hmm well to play's devil's advocate it certainly would explain relatively larger forearms and claws on supposed Nanotyrannus specimens but honestly not sure if those are legit since I don't really trust Peter Larson unfortunately

Quite understandable, but thankfully the "Duelling Dinos" specimen is currently being studied by more reliable experts. We shall have to wait and see what their published research says.

[Bread]

I don't really trust Peter Larson unfortunately

I always forget that he's part of the "Nanotyrannus is a valid genus" group.

Even if this is the start of future research for this genus name, I still hold my skepticism. I don't see how this genus name can fit into such an environment when there are plenty of other competitors already.

[suspsy]

I don't really trust Peter Larson unfortunately

I always forget that he's part of the "Nanotyrannus is a valid genus" group.

Even if this is the start of future research for this genus name, I still hold my skepticism. I don't see how this genus name can fit into such an environment when there are plenty of other competitors already.

It may not be as farfetched as that. Today's African savannah has lions, leopards, cheetahs, servals, caracals, wildcats, spotted hyenas, aardwolves, jackals, and honey badgers, and they all manage to coexist without any of them being hunted or starving to death.

[Shane]

It may not be as farfetched as that. Today's African savannah has lions, leopards, cheetahs, servals, caracals, wildcats, spotted hyenas, aardwolves, jackals, and honey badgers, and they all manage to coexist without any of them being hunted or starving to death.

Along this line, we know that Albertosaurus, Gorgosaurus, and Daspletosaurus all co-existed in the same place at the same time, so why would it be so difficult to believe that something like Nanotyrannus could co-exist amongst competition?

[Bread]

It may not be as farfetched as that. Today's African savannah has lions, leopards, cheetahs, servals, caracals, wildcats, spotted hyenas, aardwolves, jackals, and honey badgers, and they all manage to coexist without any of them being hunted or starving to death.

Along this line, we know that Albertosaurus, Gorgosaurus, and Daspletosaurus all co-existed in the same place at the same time, so why would it be so difficult to believe that something like Nanotyrannus could co-exist amongst competition?

Correct me if I am wrong, but wasn't there a lot less surplus of species in the Hell Creek formation than Dinosaur Park formation? That's why I generally considered this sort of niche for "Nanotyrannus" to not be so much possible.

Also, regarding current extant animals in Africa. Isn't there also just so much more variety as compared to Hell Creek's?
Edit: Just to add, with this in mind of Africa's savanahs, they are much larger than the Hell Creek formation. Wouldn't this also help aide in the vast variety of animals, allowing a larger amount of roles to be filled rather than constant competition(s).

I am no expert, so again correct me if I am wrong. I've just viewed and seen information regarding "Nanotyrannus" niche to not be so much as possible in the Hell Creek formation.

[Shane]

Correct me if I am wrong, but wasn't there a lot less surplus of species in the Hell Creek formation than Dinosaur Park formation? That's why I generally considered this sort of niche for "Nanotyrannus" to not be so much possible.

Also, regarding current extant animals in Africa. Isn't there also just so much more variety as compared to Hell Creek's?
Edit: Just to add, with this in mind of Africa's savanahs, they are much larger than the Hell Creek formation. Wouldn't this also help aide in the vast variety of animals, allowing a larger amount of roles to be filled rather than constant competition(s).

I am no expert, so again correct me if I am wrong. I've just viewed and seen information regarding "Nanotyrannus" niche to not be so much as possible in the Hell Creek formation.

I'm no expert so I can't "correct" you, but can we ever truly know the diversity of an ecosystem from millions of years ago? Our knowledge is dependent on what has been preserved and uncovered, and I don't think we can ever really know how many species were truly in a given area based solely on what is preserved in the fossil record.

But like I said I'm no expert in this field. I think there's probably a ton of reasons why Nanotyrannus may not be its own thing and is likely a juvenile of something else, whether it's a Tyrannosaurus or some other tyrannosaurid or tyrannosauroid...but I dunno if diversity of competition is a compelling reason.

I can't speak to what Nanotyrannus was one way or another, but I do find it fascinating that it seems like another example of people seeing something as absolute and then realizing how few absolutes there ever truly are in paleontology. A few months ago Nanotyrannus ABSOLUTELY WAS a juvenile T. rex, and there was no room for arguing further, but now...maybe not?

[Gwangi]

I think because we're living in a period of low biodiversity it is easy to assume that there shouldn't be many predators but if today's ecosystems were intact a lot of them would look more like what we see in Africa. There are parts of North America that should be home to black and brown bears, mountain lions, wolves, coyotes, bobcats, lynx, wolverines, large raptors, foxes, and other predators all coexisting together. There are a few places that still have that diversity. Go back several thousand years and you get even more species of big cat, bear, and canines existing alongside those still around today. In the Hell Creek formation you have T. rex, a few small-medium sized Eumaniraptorans, and crocodilians. I think there's room for more.

[Bread]

Correct me if I am wrong, but wasn't there a lot less surplus of species in the Hell Creek formation than Dinosaur Park formation? That's why I generally considered this sort of niche for "Nanotyrannus" to not be so much possible.

Also, regarding current extant animals in Africa. Isn't there also just so much more variety as compared to Hell Creek's?
Edit: Just to add, with this in mind of Africa's savanahs, they are much larger than the Hell Creek formation. Wouldn't this also help aide in the vast variety of animals, allowing a larger amount of roles to be filled rather than constant competition(s).

I am no expert, so again correct me if I am wrong. I've just viewed and seen information regarding "Nanotyrannus" niche to not be so much as possible in the Hell Creek formation.

I'm no expert so I can't "correct" you, but can we ever truly know the diversity of an ecosystem from millions of years ago? Our knowledge is dependent on what has been preserved and uncovered, and I don't think we can ever really know how many species were truly in a given area based solely on what is preserved in the fossil record.

But like I said I'm no expert in this field. I think there's probably a ton of reasons why Nanotyrannus may not be its own thing and is likely a juvenile of something else, whether it's a Tyrannosaurus or some other tyrannosaurid or tyrannosauroid...but I dunno if diversity of competition is a compelling reason.

I can't speak to what Nanotyrannus was one way or another, but I do find it fascinating that it seems like another example of people seeing something as absolute and then realizing how few absolutes there ever truly are in paleontology. A few months ago Nanotyrannus ABSOLUTELY WAS a juvenile T. rex, and there was no room for arguing further, but now...maybe not?

Very true. We still don't even know much about Dakotaraptor other than a few bones, even those appear to be up in the air. Though I truly believe a large dromaeosaur was definitely filling a gap in Hell Creek formation. So indeed there is still an abundance of other species we have yet to discover. My apologies for the lack of assumption. I should have thought that through.

I think because we're living in a period of low biodiversity it is easy to assume that there shouldn't be many predators but if today's ecosystems were intact a lot of them would look more like what we see in Africa. There are parts of North America that should be home to black and brown bears, mountain lions, wolves, coyotes, bobcats, lynx, wolverines, large raptors, foxes, and other predators all coexisting together. There are a few places that still have that diversity. Go back several thousand years and you get even more species of big cat, bear, and canines existing alongside those still around today. In the Hell Creek formation you have T. rex, a few small-medium sized Eumaniraptorans, and crocodilians. I think there's room for more.

Yep, it's even more exceptionally sad that my home state's Florida Panther is fading away. Although conservation is in effect, and the species is improving very slightly compared to a few years ago, it's still at an all time low in terms of biodiversity as this species of big cat was once roaming across a larger part of Florida. If I recall correctly, there were even reports of Jaguars roaming in Texas a while ago, but now due to increase borders their range has decreased.

like I said with Shane's comment, I should have thought out an assumption for more biodiversity than originally anticipated.

Here is the paper I was recalling earlier for "Nanotyrannus" and its niche filling, though juvenile Tyrannosaurus probably filled it according to the paper.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6938697/

Note, it's dated at 2020, and it also has Horner, who I know is certainly controversial but I find the paper to be pretty informative. Possibly even shared in another thread regarding this genus name.

[Gwangi]

Yep, it's even more exceptionally sad that my home state's Florida Panther is fading away. Although conservation is in effect, and the species is improving very slightly compared to a few years ago, it's still at an all time low in terms of biodiversity as this species of big cat was once roaming across a larger part of Florida. If I recall correctly, there were even reports of Jaguars roaming in Texas a while ago, but now due to increase borders their range has decreased.

like I said with Shane's comment, I should have thought out an assumption for more biodiversity than originally anticipated.

At one point jaguars were found in Texas, Arizona, California, Louisiana, and New Mexico, and possibly elsewhere. Today there are still jaguars seen wandering around in Arizona but there aren't many of them. And yeah, the plight of the Florida panther is a sad story. As is the story of eastern cougars in general.

[VD231991]

It may not be as farfetched as that. Today's African savannah has lions, leopards, cheetahs, servals, caracals, wildcats, spotted hyenas, aardwolves, jackals, and honey badgers, and they all manage to coexist without any of them being hunted or starving to death.

Along this line, we know that Albertosaurus, Gorgosaurus, and Daspletosaurus all co-existed in the same place at the same time, so why would it be so difficult to believe that something like Nanotyrannus could co-exist amongst competition?

Albertosaurus lived a few million years later than Daspletosaurus and Gorgosaurus. When George Olshevsky made the case for more than one non-alioramin tyrannosaurine taxon co-existing in the Nemegt Formation, he pointed out that lions and leopards co-exist with each other in the African savannah, but given that we know that Maleevosaurus and Tarbosaurus efremovi are conspecific with Tarbosaurus bataar, it is unclear whether Olshevsky's opinion was analogous to the diversity of Panthera species in Africa because we don't know for sure the coloration of Tarbosaurus (the differences between the coloration of lions and leopards are well-known). Nevertheless, the distinctness of the alioramins from Tarbosaurus, Raptorex and Zhuchengtyrannus indicates than there are parallels between tyrannosaurid diversity in East Asia during the Maastrichtian and the existence of more than one species of pantherine in Africa because three valid alioramin species have been described so far.