T Rex or Nanotyrannus?

[DPS Ammonite]

10 minutes ago, CBchiefski said:

@DPS Ammonite That is a difficult question and rather complex. It is honestly is one I try to avoid, in short, depends on the institution as some have the funds, but most simply do not. Sue being bought for such a large amount did radically increase the value of fossils, in many ways it was a paradigm shift. Many buys do not have a major impact on the value of fossils but after sue, the market prices went up for everything, so I suppose like most aspects of life, it depends. 

Let me rephrase my question. If a paleontologist wanted to officially describe a fossil, would it be ethical or a confict of interest to buy the fossil to be described?  Large amounts of cash can make fossil sellers misrepresent their wares.

[CBchiefski]

11 minutes ago, DPS Ammonite said:

Let me rephrase my question. If a paleontologist wanted to officially describe a fossil, would it be ethical or a confict of interest to buy the fossil to be described?  Large amounts of cash can make fossil sellers misrepresent their wares.

Outside of the potential price impacts for every buy down the road, I would personally say no. Of course, I can only speak for myself.  Like most buyers, I think any paleontologist would want to ensure it was worth buying long before that option was explored. The specimen would need to be worth every dollar since most institutions are already pressed for funds. A perfect example in relatively recent times is Zuul the new ankylosaur, it was bought and there will be many publications on that specimen. Will not state the amount Zuul was sold to the ROM for, let's just say it was quite a bit and I think many in the field agree, the price was justified given the amazing condition.

Edited October 26, 2018 by CBchiefski
Typo

[Miocene_Mason]

@CBchiefski did you see Laurel the Juvenile T. rex also announced at SVP 2018? I wasn’t there, but here’s some pictures I saw from Facebook of it (source:Here). I think it was a team from KU. I’m not too knowledgeable on dinosaur teeth but they look pretty robust on this one, and it is labeled as a T. rex. Could be a counterpoint to the Bone histologies...

[CBchiefski]

On 10/25/2018 at 7:40 PM, WhodamanHD said:

@CBchiefski did you see Laurel the Juvenile T. rex also announced at SVP 2018? I wasn’t there, but here’s some pictures I saw from Facebook of it (source:Here). I think it was a team from KU. I’m not too knowledgeable on dinosaur teeth but they look pretty robust on this one, and it is labeled as a T. rex. Could be a counterpoint to the Bone histologies...

 

 

 

Yes, I saw that talk, and nothing presented directly supports or falsifies the Nano hypothesis. The specimen does need a detailed description as the number of teeth was changed between the abstract and the talk which does raise some questions about the initial interpretation. Not saying I am taking issue with the researchers, it is good to see corrections made however the need for a correction in the first place and so soon afterwards, makes me wonder about the rest of their interpretation. They are using measurements to show its overall size which based on the above picture is problematic, as the maxilla shows deformation, note it has a lateral curve moving anterodistal along the bone. For those not familiar with anatomy, the bone above curves away from the rest of the mouth area with this curve becoming greater toward the front of the animal. I think this is taphonomic, but if it is the natural shape of the bone than the specimen is very interesting. T-rex does often have a robust maxilla but this is unusual compared to most. For the teeth, it is noted in a publication already listed in this thread that the dental morphology is a poor and ineffective way to differentiate many tyrannosaurids, therefore it is best to be very conservative when using teeth.
 

Not sure what you mean by a "counterpoint to the Bone histologies" as no histology was done on this specimen and sadly there are no associated bones which histology could be done on. Histology works well as an indicator of age for every bird and croc so far tested. These two clades bracket dinosaurs so if the testing method works on them, then it is sound logic to assume it works with dinosaurs. Histology does have some flaws but is vastly superior when compared to making age assumptions just off size.
 

[Miocene_Mason]

@CBchiefski I did not get a chance to see the talk or the abstract as I’m not yet a member of SVP (which I hope to change soon), so all I know of it is gleened from the pictures and what I’ve heard from others. I was saying a counterpoint in that if this is a juvenile T. rex, then what is Jane? The histology was a piece of evidence in support of invalidating N. lancensis and Laurel is a possible point in support of it’s validity. This specimen appears to me (uneducated in the matter as I am) to have more robust teeth, with a circular cross section in the crown, rather than the hourglass-shaped cross section of Jane’s and the teeth referred to as nanotyrannus by collectors. Of course this could just be intraspecies variation or differences in stages of growth, or I could just be confused.

I too assumed the curve was taphonomic, T. rex skulls seem to be prone to plastic deformation. 

[Miocene_Mason]

Okay, not to bring back a post from so long ago, but I thought I’d put a final reply in as I had been meaning to do. Thanks to @CBchiefski, I have read the abstract and I have a better idea of what’s happening here.

 

The abstract itself made no reference to the Nanotyrannus. The authors appear to be very careful to just describe the specimen and it’s attributes rather than turn it into a commentary on the debate, which could be for a few reasons. Anyway, while making no direct references to the debate, it seems to imply or at least nudge in the direction of its possible use as evidence in this debate. It directly compares it to Jane. It says Laurel has a congruent number of alveoli to sue (12), and the maxillary tooth count is higher than Jane. Most strikingly for me, Laurel has a first pre-maxillary tooth much different than Jane’s. That would imply, for me, that Jane and Laurel are somehow different, be it subspecies, species, genus or simply a strange allele possessed by some T. rex. 

 

That being said, the bone histologies in Jane are pretty damning. That’s does not necessarily mean that the two taxon aren’t different, just that Jane is a juvenile. If they find an associated long bone with Laurel, histologies could be done on it to see where it is in relation to Jane. That may lend support to the Nanotyrannus hypothesis depending on what it finds. 

 

So, the debate goes on. Right now it seems that the juvenile T. rex theory is stronger, but the possibility of this being incorrect still exists.

[Abstraktum]

Well I'm no expert or anything and I have no idea if Nano is now a juvenile T Rex or not.

But I just want to throw in the juvenile/young/nearly adult T Rex that is in Bavaria / Germany. I already posted about it, but some may didn't see it. 

 

http://www.thefossilforum.com/index.php?/topic/86893-tyrannosaurus-rex-exhibition-in-munich/

 

Bavarian T Rex has a size of around 10 meters (32.8 ft), Jane is 6,5 meters (21.3 ft).

[CBchiefski]

On 12/17/2018 at 6:35 AM, WhodamanHD said:

The abstract itself made no reference to the Nanotyrannus. The authors appear to be very careful to just describe the specimen and it’s attributes rather than turn it into a commentary on the debate, which could be for a few reasons. Anyway, while making no direct references to the debate, it seems to imply or at least nudge in the direction of its possible use as evidence in this debate. It directly compares it to Jane. It says Laurel has a congruent number of alveoli to sue (12), and the maxillary tooth count is higher than Jane. Most strikingly for me, Laurel has a first pre-maxillary tooth much different than Jane’s. That would imply, for me, that Jane and Laurel are somehow different, be it subspecies, species, genus or simply a strange allele possessed by some T. rex. 

 

That being said, the bone histologies in Jane are pretty damning. That’s does not necessarily mean that the two taxon aren’t different, just that Jane is a juvenile. If they find an associated long bone with Laurel, histologies could be done on it to see where it is in relation to Jane. That may lend support to the Nanotyrannus hypothesis depending on what it finds. 

 

So, the debate goes on. Right now it seems that the juvenile T. rex theory is stronger, but the possibility of this being incorrect still exists.

Indeed, and the histology is the key point as teeth and bones can change drastically during growth. Regardless of what it is classified as, Jane is not an adult which means there should be a similar, larger animal present. The only animal which fits then is T rex, of course, there are animals in the formation which we are unaware of but till we find them, there is nothing to work with.

In the prior post, I bring up the alteration to show how poor size is as a way to gauge age. Size can be altered by the fossilization process and while we can reconstruct bones, there is always an amount of error in any reconstruction. It will be good to have you in the society, just maintain the curiosity, skepticism, and kindness you show on here and you will be a great addition.
 

On 12/17/2018 at 2:55 PM, Abstraktum said:

Well I'm no expert or anything and I have no idea if Nano is now a juvenile T Rex or not.

But I just want to throw in the juvenile/young/nearly adult T Rex that is in Bavaria / Germany. I already posted about it, but some may didn't see it. 

 

http://www.thefossilforum.com/index.php?/topic/86893-tyrannosaurus-rex-exhibition-in-munich/

 

Bavarian T Rex has a size of around 10 meters (32.8 ft), Jane is 6,5 meters (21.3 ft).

Yes, if I recall correctly that one was stated as a sub adult.  Very nice, thanks for sharing.

[Miocene_Mason]

1 hour ago, CBchiefski said:

there should be a similar, larger animal present. The only animal which fits then is T rex, of course, there are animals in the formation which we are unaware of but till we find them, there is nothing to work with.

Very true. I’m sure the future will bring more evidence for or against it, plenty more Tyrannosaurs left to be found. Let’s hope some are juvenile. I’m also excited to see what the future holds for the differences in tooth morphology, assuming the juvenile T. rex theory holds. Strange how few juveniles have been found compared to the relatively large amount of adults, guess they just grew so quick that statistically adults are vastly more commonly. 

 

1 hour ago, CBchiefski said:

It will be good to have you in the society, just maintain the curiosity, skepticism, and kindness you show on here and you will be a great addition.

Thank you, I’ll certainly try! I’m currently working to become more connected with those in the field as I need a letter of recommendation to join as a junior member, though I’ll only be one for a short time. Until then, I’m having fun simply meeting paleontologist and enthusiasts in my area and talking to/learning from all the people on here!