Nanotyrannus on Dino Hunters

[andrewsaurus rex]

ok, so i know the validity of Nanotyrannus is hotly debated and that the general consensus is that it's a juvenile T Rex but I was watching Dino Hunters last night and Peter Larson was on it with some pretty convincing evidence demonstrating that Nanotyrannus is valid and not a juvenile Rex.

Aside from the number of teeth (weak argument) and the more fused nasal bones on Nano (not a bad argument) he compared hand bones from T Rex and hand bones from a recently discovered skeleton of 'Nanotyrannus' and the hand bones on the new skeleton were larger than those of any adult Rex.

While the number of teeth in a tyrannosaur may change as it grows, I just don't see the hands and presumably arms shrinking as it grows.

I've looked online and there is very little mention of this discovery and nothing seems to have changed in the debate over Nano, as a result of this discovery.

What's going on?

[Dynomikegojira]

Just glad that the Bloody Mary tyrannosaur is being described by Zanno at a museum so we'll know within the next couple of years whether Nanotyrannus or a similar dinosaur actually existed. The forearms I think is the most convincing argument in Nanotyrannus's favor but personally it think it's very suspicious that most of the supposed Nanotyrannus specimens are in private collection so other paleontologists can't verify Larsons's claims unfortunately and apparently Nanotyrannus is a major selling point for commercial paleontologists. So basically until we get confirmation of what the Bloody Mary specimen is or if we were to discover a similar specimen in the field with clear distinct differences that match Larson's description I still believe that we're dealing with a juvenile Tyrannosaurus and I think that's how most paleontologists feel as well.

[andrewsaurus rex]

Interesting comments.  You are implying that Larson is not being truthful in his assertions  Would he deliberately lie?  It can't be construed as him misinterpreting the fossils, as it is pretty easy to tell if the hands are bigger or not, especially for a T rex expert.

I have no opinion on Nano one way or the other. I'm waiting to see what happens.  I would not be surprised at all if Nano was real.  It would be sort of a fox to the T rex wolf.  There are big and little canines extant at the same time and cats and bears.  Why not tyrannosaurs too?  Seem plausible but of course that doesn't mean it's the way it was. 

[Dynomikegojira]

It's more I don't trust commercial paleontologists than Greg Larson but they way I see it until other paleontologists can verify his claims about Nano I'm skeptical we don't need another Archeoraptor situation

[Halichoeres]

Nobody is immune to perverse incentives, and being exposed to perverse incentives doesn't necessarily mean someone will be underhanded or corrupt. That said, being a private dealer provides more incentives to overstate the importance of your holdings than being a scientist at a nonprofit institution, and can lead a person to fool even themselves about a particular taxon. I don't know enough about the specifics of these specimens to offer an opinion. However, this seems like a relevant study: https://science.sciencemag.org/content/371/6532/941

Because predatory dinosaurs had to start small and probably had a really limited window of parental care, there might not have been ecological space for mid-sized carnivores. Because of the different reproductive biology of dinosaurs compared to carnivoran mammals, we just shouldn't expect things like jackals or coyotes between the foxes and wolves (to use a very imperfect analogy). The absence of these mid-sized carnivores holds in a variety of different environments over many millions of years, according to the above study.

[andrewsaurus rex]

Also interesting comments.

The only problem I have with drawing conclusions from studies of prehistoric environments is that the known fauna of those environments could well be incomplete, thus skewing the conclusions.  Just by the nature of the way they lived, some animals could have been more likely to be fossilized than others or just by chance there are animals from those environments that just have not been discovered yet.

To me, it does not seem unreasonable that there were other theropods of reasonable size, co-existing with T rex, other than just younger versions of T rex filling all the predatory niches.  Afterall, in the Morrison, there were at least 3 significant predators: Allosaurus, Ceratosaurus and Torvosaurus co-existing.  Dakotaraptor co-existed with T Rex sub adults and may have competed with them, so why not others as well?

Now, it's entirely possible that T rex was so dominant that all other competition was wiped out or forced to stay diminutive in size.  If so, that really flies in the face of people who still believe that T rex was primarily a scavenger.

[Gothmog the Baryonyx]

Nobody seriously believes that Tyrannosaurus was primarily a scavenger.

I would say that unless something very convincing emerges, I would err on the side of synonymy for this one. There doesn't appear to be much in favour of the existence of Nanotyrannus but wishful thinking.

[andrewsaurus rex]

Nobody seriously believes that Tyrannosaurus was primarily a scavenger.

I would say that unless something very convincing emerges, I would err on the side of synonymy for this one. There doesn't appear to be much in favour of the existence of Nanotyrannus but wishful thinking.

But there are still those that do believe in scavenger Rex.  And I remember a time when it was a theory with a lot of traction and supporters.

[Halichoeres]

Also interesting comments.

The only problem I have with drawing conclusions from studies of prehistoric environments is that the known fauna of those environments could well be incomplete, thus skewing the conclusions.  Just by the nature of the way they lived, some animals could have been more likely to be fossilized than others or just by chance there are animals from those environments that just have not been discovered yet.

To me, it does not seem unreasonable that there were other theropods of reasonable size, co-existing with T rex, other than just younger versions of T rex filling all the predatory niches.  Afterall, in the Morrison, there were at least 3 significant predators: Allosaurus, Ceratosaurus and Torvosaurus co-existing.  Dakotaraptor co-existed with T Rex sub adults and may have competed with them, so why not others as well?

Now, it's entirely possible that T rex was so dominant that all other competition was wiped out or forced to stay diminutive in size.  If so, that really flies in the face of people who still believe that T rex was primarily a scavenger.

To me, the probability that comparing multiple environments across different continents and geological periods will give us the wrong answer is lower than the probability that a single hand on a single specimen promoted by a person who has a financial stake in the specimen will give us the wrong answer.

[austrosaurus]

Larson is a corporatist hack and Dino Hunters is utter garbage so I wouldn't take anything either says at face value.

[GojiraGuy1954]

ok, so i know the validity of Nanotyrannus is hotly debated and that the general consensus is that it's a juvenile T Rex but I was watching Dino Hunters last night and Peter Larson was on it with some pretty convincing evidence demonstrating that Nanotyrannus is valid and not a juvenile Rex.

Aside from the number of teeth (weak argument) and the more fused nasal bones on Nano (not a bad argument) he compared hand bones from T Rex and hand bones from a recently discovered skeleton of 'Nanotyrannus' and the hand bones on the new skeleton were larger than those of any adult Rex.

While the number of teeth in a tyrannosaur may change as it grows, I just don't see the hands and presumably arms shrinking as it grows.

I've looked online and there is very little mention of this discovery and nothing seems to have changed in the debate over Nano, as a result of this discovery.

What's going on?

Jane, the nanotyrannus holotype, is considered to be a juvenile tyrannosaurus. So even if "Nano" existed, the genus name is invalid.

[andrewsaurus rex]

ok, that's a valid point but it's just labels.  I'm not concerned about the genus name being valid, my interest is whether there was a small tyrannosaur alive at the same time as T-rex, whether it be called Nanotyrannus or IttyBittyTyrannus or something else doesn't really matter to me.

[GojiraGuy1954]

ok, that's a valid point but it's just labels.  I'm not concerned about the genus name being valid, my interest is whether there was a small tyrannosaur alive at the same time as T-rex, whether it be called Nanotyrannus or IttyBittyTyrannus or something else doesn't really matter to me.

Most likely no because all of our "Nanotyrannus" specimens are juveniles