"Dueling Dinosaurs" for sale

[wings]

...until there is new evidence that contradicts our currently knowledge (histological analysis showing it is an adult, three fingers, ect.)

There was a paper that briefly mentioned a histological study on "Jane"; sections of a rib, fibula and metatarsal were examined and the result indicates that the animal was approximately 11 and still in the rapid growth phrase (Henderson and William 2008). Based on Anderson's formula (on long-bone circumference to calculate the weight of an animal); "Jane" was found to be about 560kg (Larson 2013, though it is difficult to determine how accurate this number is). If we take a look at the histological analysis by Erickson et al. (2004, http://www.biology.ualberta.ca/courses.hp/biol506.hp/pdfs/Erickson%2704_Nature.pdf) and we plot "Jane"'s mass and age on this graph what you'll see is that "Jane" is actually somewhere near the beginning of the "rapid growth phrase" (though it doesn't sit exactly on any of these curves). Now this is the interesting part, the result could be interpreted in two different ways, depending on your preference. At this point I don't think people are debating the age of the animal (roughly 11 or 12 years old, since no one has yet published a finding which contradicts this), so it is a juvenile animal.  For people who favor the idea of it being a juvenile Tyrannosaurus would say yes this is just one of the young animal of the species (stage 1). On the other hand, for people who favor that this is actually a new specie of tyrannosaurs the "Nanotyrannus" would say that this animal might just follow similar growth curves as other tyrannosaurs species (namely Daspletosaurus, Gorgosaurus and Albertosaurus which plateau a lot sooner than Tyrannosaurus) rather than it grows to 10 folds of its body weight in 10-15 years or so as found in Tyrannosaurus, after seeing the fused hips and other fused elements of the animal as some might view the closure of suture would limit the amount of growth.

[Simon]

Thank you.  So the Dueling "Nanotyrannus'" arms are at least as large as Sue's, perhaps a tad longer.  Given its tiny size, I am still favoring the new critter theory rather than a juvi TRex....

[Dinoguy2]

Thank you.  So the Dueling "Nanotyrannus'" arms are at least as large as Sue's, perhaps a tad longer.  Given its tiny size, I am still favoring the new critter theory rather than a juvi TRex....

Where were the lengths of the Dueling specimen's arms published? Or is this all based  on eyeballing a perspective shot next to Bakker's arm? Do we know how long his arms are?

[Simon]

The Dueling Dinos site is temporarily down, which is why the pictures I linked to upthread have disappeared.  One of them shows a tapemeasure next to the Nano's hand.  It is exactly 12 inches long from the wrist to the tip of the longest claw.  The forearm and upper arm bones each looked like they might be a little shorter than that.  So we are arriving at the same exact estimate that you gave for Sue's arms, ie anywhere from 2.5 to near 3 feet....

[SBell]

Thank you.  So the Dueling "Nanotyrannus'" arms are at least as large as Sue's, perhaps a tad longer.  Given its tiny size, I am still favoring the new critter theory rather than a juvi TRex....

Where were the lengths of the Dueling specimen's arms published? Or is this all based  on eyeballing a perspective shot next to Bakker's arm? Do we know how long his arms are?

They aren't published anywhere, at least not in a peer-reviewed article. That is the main issue with things like this auction--given the the buyer will probably not be a researcher, there is the possibility that the specimen will never be properly published (SVP rules, for example, won't allow for publication of privately held specimens because of the lack of potential follow-up study access. At least that's how I recall things). So the answer will remain indeterminate (unless molds and casts are made and provided--perhaps then data could be collected, if not formally published on!).

[wings]

The Dueling Dinos site is temporarily down, which is why the pictures I linked to upthread have disappeared.  One of them shows a tapemeasure next to the Nano's hand.  It is exactly 12 inches long from the wrist to the tip of the longest claw.  The forearm and upper arm bones each looked like they might be a little shorter than that.  So we are arriving at the same exact estimate that you gave for Sue's arms, ie anywhere from 2.5 to near 3 feet....

Are you referring to these pictures?





and here is "Sue"'s arm, there are scale bars on these images but just double check with the given measurements (just in case if the bars are wrong because sometimes it does happen...)



and once you've adjusted the scale of these elements; "Sue"'s arm might look something roughly like this (below)

[Simon]

Thanks.  Looks like Sue's upper arm is longer, the forearm about the same size, and the hand + claws about the same length as the Nanotyrannus.  As I said before, this leads me to think that the Nano is not a juvi-TRex.

[wings]

....Thanks for the photos by the way. The fact that Larson is calling that metacarpal with a tiny articular surface a third digit has convinced me he's more interested in helping hype-up the price of the specimen rather than in doing science...

This is not for or against the idea of "juvenile Tyrannosaurus" / "Nanotyrannus" but it does appear that having a "third digit" is not such a unique feature (https://gsa.confex.com/gsa/2007AM/finalprogram/abstract_132345.htm). Also noted that this "feature" is not included in Larson's "more" formal publications (on the validity of Nanotyrannus).

[Dinoguy2]

Thanks.  Looks like Sue's upper arm is longer, the forearm about the same size, and the hand + claws about the same length as the Nanotyrannus.  As I said before, this leads me to think that the Nano is not a juvi-TRex.

So an adult specimen has slightly longer arms than a juvenile in a species that is known for its reduced arm length, so this leads me to think Nano is a juvi T. rex.

The fact is we have no idea how arms developed as tyrannosaurs grew. We know that they didn't grow isometrically, or else young tyrannosaurs would have giant skulls. We know the skull started relatively large compared to the body but then stayed relatively small as the body grew (see Gorgosaurus, Tarbosaurus). We don't really know what the arms were doing in those middle years, or what variation might exist between species in terms of growth pattern.

It's too bad we don't have any arms of Alioramus, which is around the same size/growth stage.

Without statistical analysis vs. other tyrannosaurs and histology, unfortunately no feature of this skeleton can possibly be used to support either side of the debate.

[wings]

...Without statistical analysis vs. other tyrannosaurs and histology, unfortunately no feature of this skeleton can possibly be used to support either side of the debate.

You meant "allometry", right? since we actually do have research on histology on various tyrannosaur species (see http://www.biology.ualberta.ca/courses.hp/biol506.hp/pdfs/Erickson%2704_Nature.pdf) which was mentioned a few posts back. Often I would wonder if it is so important for the scientific community to formally acknowledge whether this animal (the dueling dinosaurs) is a "Nanotyrannus" / a juvenile Tyrannosaurus or not. Of course it would be better if we have more specimens of it, but for the time being we still have other materials to study on (like "Jane"). I suppose we can extrapolate measurements of some of its skeletal elements (informally) or identifying special features (such as the pneumatization of the quadratojugal) the only drawback is that we can't use any of these info on a scientific publication but personally I don't see it as a big issue. Does proving the identity of this particular animal make much different to the current discussion on whether "Nanotyrannus" is real? Since we can't use the info extracted from this animal formally then why does it matter...

...We know the skull started relatively large compared to the body but then stayed relatively small as the body grew (see Gorgosaurus, Tarbosaurus). We don't really know what the arms were doing in those middle years, or what variation might exist between species in terms of growth pattern.

It's strange but somehow you would infer the skull ratio to other tyrannosaurs. On the other hand, if I would have used the same logic then can't we just infer the arm growth pattern of Tyrannosaurus to the Tarbosaurus's (since we do have quite a "complete" growth series for them with arms). Again we just don't know for certain.

[Dinoguy2]

...Without statistical analysis vs. other tyrannosaurs and histology, unfortunately no feature of this skeleton can possibly be used to support either side of the debate.

You meant "allometry", right? since we actually do have research on histology on various tyrannosaur species (see http://www.biology.ualberta.ca/courses.hp/biol506.hp/pdfs/Erickson%2704_Nature.pdf) which was mentioned a few posts back. Often I would wonder if it is so important for the scientific community to formally acknowledge whether this animal (the dueling dinosaurs) is a "Nanotyrannus" / a juvenile Tyrannosaurus or not. Of course it would be better if we have more specimens of it, but for the time being we still have other materials to study on (like "Jane"). I suppose we can extrapolate measurements of some of its skeletal elements (informally) or identifying special features (such as the pneumatization of the quadratojugal) the only drawback is that we can't use any of these info on a scientific publication but personally I don't see it as a big issue. Does proving the identity of this particular animal make much different to the current discussion on whether "Nanotyrannus" is real? Since we can't use the info extracted from this animal formally then why does it matter...

...We know the skull started relatively large compared to the body but then stayed relatively small as the body grew (see Gorgosaurus, Tarbosaurus). We don't really know what the arms were doing in those middle years, or what variation might exist between species in terms of growth pattern.

It's strange but somehow you would infer the skull ratio to other tyrannosaurs. On the other hand, if I would have used the same logic then can't we just infer the arm growth pattern of Tyrannosaurus to the Tarbosaurus's (since we do have quite a "complete" growth series for them with arms). Again we just don't know for certain.

Well, you can't bracket based on one relative, you need two. But, come to think of it we DO have an upper bound for subadult tyrannosaur arm growth in a bracket-able species--the famous, nearly complete subadult Gorgosaurus libratus specimen. The arms on that are relatively small, similar to the proportions of an adult Gorgosaurus. There are also large subadult Tarbosaurus specimens that appear to have tiny arms, but I don't know how much of that is reconstruction. So, to me, that's one pretty compelling data point in favor of Nano being valid, *assuming* Gorgosaurus and Tarbosaurus grow the same way as T. rex (and given phylogenetic bracketing, that's a fair assumption). It would still be nice to have an adult Nano with diagnostic nano features or a young T. rex lacking them to really support the hypothesis, though.

[wings]

...Well, you can't bracket based on one relative, you need two. But, come to think of it we DO have an upper bound for subadult tyrannosaur arm growth in a bracket-able species--the famous, nearly complete subadult Gorgosaurus libratus specimen. The arms on that are relatively small, similar to the proportions of an adult Gorgosaurus. There are also large subadult Tarbosaurus specimens that appear to have tiny arms, but I don't know how much of that is reconstruction. So, to me, that's one pretty compelling data point in favor of Nano being valid, *assuming* Gorgosaurus and Tarbosaurus grow the same way as T. rex (and given phylogenetic bracketing, that's a fair assumption). It would still be nice to have an adult Nano with diagnostic nano features or a young T. rex lacking them to really support the hypothesis, though.

Of course there are more than one relative to examine apart from Tarbosaurus; we also have Albertosaurus (http://en.wikipedia.org/wiki/Albertosaurus) and Gorgosaurus (http://en.wikipedia.org/wiki/Gorgosaurus) growth series. The only reason I put the Tarbosaurus comment (which is just a throw in comment and not a serious one by the way) in because the possibility of this condition could well be different between species and we just don't know for sure at this point (I just don't think we could actually say "We know..." as you did from the previous post. ). It shouldn't be too hard to find some of Maleev's paper on Tarbosaurus to see which specimen is reconstructed (so it's just a matter of putting some effort to look them up to verify the authenticity on some of these) or even try to look up the specimen number which sometimes the institute would give description on.

[HD-man]

GOOD NEWS: "Two fossilized dinosaurs discovered side-by-side in the Montana badlands failed to sell when they went under the hammer in here Tuesday (Nov. 19), despite projections that they would break auction records...Auction house officials said they are hopeful the dinosaur duo will find a home and are now entering into negotiations with interested U.S. institutions" ( http://www.livescience.com/41325-dueling-dinosaur-fossils-fail-to-sell-auction.html ).

[Balaur]

Yes! I was really worried. I'm just surprised that museums are funded enough.

[Gorgonzola]

There was actually quite a lot that didn't sell at that auction - a nearly complete Triceratops skull, a T. rex skeleton, an Edmontosaurus skull, a mounted Triceratops skeleton...seems like whoever appraised this stuff placed it way too high, bids were tepid the whole auction and pretty much everything had a high bid that was half the expected value.

[SBell]

Yes! I was really worried. I'm just surprised that museums are funded enough.

They aren't. But the auctionhouse is probably trying to find a way to make money still.

Good to see that common sense is starting to prevail on these--I'm guessing that they are so over-valued because there is very little potential for an increase in investment, which is often a driving factor for artifacts and relics.

[HD-man]

If you view the size of the arm compared to the body you quickly realize that this can't possibly be a "juvenile TRex".  It is larger than the arms of full-grown TRexes.  It almost makes the critter look raptor-like.  Its a new tyrannosaurid for sure

I recently read about that & you're right (See the Bakker quote).

Quoting Bakker ( http://science.slashdot.org/story/13/03/10/2217251/dr-robert-bakker-answers-your-questions ):

Later digs in the Late Cretaceous provided ballistic evidence that tyrannosaur species fed in families too. The Black Hills Institute excavated a fine adult Triceratops who had tooth-marked bones (specimen now on display at The Childrens Museum of Indianapolis, a superb institution). All around the T'tops were some forty shed teeth, juvenile and adult, from the small tyrannosaurid Nanotyrannus. Clearly young and full-grown predators had fed together.

(Some colleagues have accused Nano's of being juvenile T. rexes; new finds debunk the idea. The "Dueling Dinosaurs of Montana" discovery includes a full grown Nano that demonstrates the key differences: Adult Nano's have heads and bodies only half the size of a full-grown T. rex but the Nano arms and fingers are twice as massive and carry claws that dwarf those of a rex. At all growth stages, Nano teeth are far sharper than rex chompers.)

[SBell]

If you view the size of the arm compared to the body you quickly realize that this can't possibly be a "juvenile TRex".  It is larger than the arms of full-grown TRexes.  It almost makes the critter look raptor-like.  Its a new tyrannosaurid for sure

I recently read about that & you're right (See the Bakker quote).

Quoting Bakker ( http://science.slashdot.org/story/13/03/10/2217251/dr-robert-bakker-answers-your-questions ):

Later digs in the Late Cretaceous provided ballistic evidence that tyrannosaur species fed in families too. The Black Hills Institute excavated a fine adult Triceratops who had tooth-marked bones (specimen now on display at The Childrens Museum of Indianapolis, a superb institution). All around the T'tops were some forty shed teeth, juvenile and adult, from the small tyrannosaurid Nanotyrannus. Clearly young and full-grown predators had fed together.

(Some colleagues have accused Nano's of being juvenile T. rexes; new finds debunk the idea. The "Dueling Dinosaurs of Montana" discovery includes a full grown Nano that demonstrates the key differences: Adult Nano's have heads and bodies only half the size of a full-grown T. rex but the Nano arms and fingers are twice as massive and carry claws that dwarf those of a rex. At all growth stages, Nano teeth are far sharper than rex chompers.)

But did he study the 'dueling dinos' or is he just quoting what he's heard about it? It's never been subject to any rigorous measurement or publication, so much of what has been said about it appears to have been more of an attempt to drive the value up by trumpeting its importance (which cannot be denied, of course, but the purpose of establishing importance here is for bigger money).

[Simon]

Since the Nanotyrannus "dueling" skeleton is pretty much completely exposed, I would guess that yes, Bakker DID measure the arm bone.  Ditto the skull and teeth. He has been the consultant to the guys that dug it up from the beginning.  He is more familiar with it than anyone else.

You can see him on youtube taking a walk-around the skeleton and its obvious that the Nano's arms are larger than an adult Trex' arms.  Therefore it cannot be a juvi TRex, just based on that one observation, but a relative that filled a different niche of the contemporary ecosystem.

[Yutyrannus]

Since the Nanotyrannus "dueling" skeleton is pretty much completely exposed, I would guess that yes, Bakker DID measure the arm bone.  Ditto the skull and teeth. He has been the consultant to the guys that dug it up from the beginning.  He is more familiar with it than anyone else.

You can see him on youtube taking a walk-around the skeleton and its obvious that the Nano's arms are larger than an adult Trex' arms.  Therefore it cannot be a juvi TRex, just based on that one observation, but a relative that filled a different niche of the contemporary ecosystem.

That's what I've thought all along, there is so much evidence against it being a juvenile Tyrannosaurus as opposed the the extremely limited amount of evidence for it that I'm surprised this is just being realized now.