Tinker the juvenile Tyrannosaurus
An online interview with Mike Matheny by Samuel Barnett
In this interview I make reference to things I have read or noticed elsewhere. The two main sources are here and I urge you to read them:
New story on the discovery
The story by Michael Matheny at the official Tinker website
The first question in this online interview takes the form of a posting I made late last year to the official Tinker website’s message board:
I read on this site, a claim that the theory of Nanotyrannus being a juvenile Tyrannosaurus rex was put out of the window by the discovery of Tinker on the grounds that their teeth were different. Now Nanotyrannus is approximately 40% - 50% the size of T. rex. Tinker from the various estimates on the site seems to be 65% to 75%. The site mentioned that crocs have needle teeth when they're younger and proper teeth as they grow up. Perhaps what this find is telling us is that half-sized tyrannosaurus rex still have their baby teeth but Tinker size ones have grown their full teeth. I don't see how it could rule out Nanotyrannus as a juvenile Tyrannosaurus at all - is there something more to the find than this that would indicate seperate species?
and here is the response I got from Michael Matheny – official spokesman to the Tinker team:
I don't think it's a real good idea to rule out much of anything in Paleontology...well, maybe ruling out flying T rexes would be ok, but you know what I mean...there is still a tremendous amount to be learned and much of today's 'conclusions' will be tomorrows jokes. And that's one of the neat things about this science...it is growing and evolving so fast.
Do Tinker's teeth rule out the Nano question? Well, consider this. While Tinker may have had different teeth as a baby, as a 60% adult sized juvenile he had the same teeth as Mom and Dad. Tinker is the same size as an adult Nano. Adult Nanos have totally different teeth than Tinker. This would certainly be a strong indicator that Nanos are NOT T.rexes.
Also, I read a description of the Nano skull that mentioned that the snout was sharper, more 'foxlike' and that Nano's eyes may have been set for forward on the face giving better binocular vision than a T.rex.
From what I understand of Tinker's skull remains, they are classic T.rex in shape.
I haven't heard of any additional Nano remains having been discovered...or more probably, they have been discovered and they are sitting in some dusty drawer somewhere, unidentified...like the skull was.
You could probably stake out a nice career for yourself as a paleontologist by doing all of your field work in museum storage vaults and drawers.
Of course I had more to discuss and so I immediately contacted Mr Matheny for a few follow-up questions:
Me
I have heard many size predictions for Tinker - 23 feet from CNN news, 75%
adult size from somewhere else, between 63% and 65% from the
individual elements listed and now 60% from you. Now I appreciate that this
specimen is largely buried at present, but how did you come up with this
figure?
Mike
Dr. Bakker's initial estimate was 2/3 adult size, 1/4
adult weight. As you know, Tyrannosaurs, like humans, came in different
sizes, so Dr. Bob's estimates are based on the presumed 'average'
T.rex. (Where did '75%' come from?) ...so whether Tinker is 60%,
66%, or 57%...kind of a moot point as a precise determination is impossible...2/3 gets the idea across.
Me
Fair enough - let's look at maximum/minimum margins for error then: You
mentioned 57 - 66 percent. Do you see the new find overlapping the 40 - 50
percent rex size of Nanotyrannus as indicated by Carr in his recent JVP
paper on Tyrannosaur growth stages? Dr Holtz quoted 550mm from snout tip to
occipital condyle for the nano as compared to 1530mm for the same
measurement in Sue (admittedly Sue is a large rex even by T rex standards).
Is there any length of the skull taken so far for Tinker?
Mike
So far there are no measurements of Tinker's skull as most of the pieces are still in
matrix (half of lower jaw with a couple of attached teeth has been
removed and we've sent it off for casting...one of Kim's priorities is
the removal of skull bits).
Me
Having spoken to Thomas Holtz jr on the matter, he brought up the fact that,
whether it is a juvenile T rex or not, Nanotyrannus IS a juvenile
something - it has a juvenile bone texture.
Mike
Dr. Holtz's impressions on Nano being a 'juvenile something' could certainly be right. The 'adult something' of that species apparently hasn't been found yet...of course, that doesn't mean it’s a T rex. I hadn't heard that the Nano skull might be a juvenile. Haven't been able to catch up to Bakker to see what he thinks.
As an aside, if the nano teeth are the same size as the teeth in the original Nano find, that would mean that another 'juvenile' Nano has been found...I'm not
comfortable with the odds on that...If these teeth are the same size as
the original, then I'm thinking adult...just a thought).
Me
It appears that there is
a strong sexual dimorphism between specimens of Tyrannosaur, hence the
robust morph and the gracile, or do you agree with Dr Bakker's
interpretation of keeping the name "Dynamosaurus imperiosus" for one of the
morphs?
Mike
I'll bet the big
bucks that female tyrannosaurs were larger than males and that T.rex
social structure was female dominated...I say this because I like the
idea and it coincides with Pete Larson's ideas on dimorphism...however,
this is still a 'scientific guess' and so far not proven...since the
whole idea is based on today's crocs...that extra bit of chevron to hold
the penile retractor muscle in males...and MAYBE the same holds true for
rexes.
Me
If Tinker is the same size as a nano, could it be that the differences between them are sexually dimorphic?
Mike
Could be, but I don't think they'd have different teeth.
Me
How do you know that the teeth found at the location were Nano teeth and
not, for instance, those of the Lancian Tyrannosaurid - Aublysodon (Stygivenator)
molnari?
Mike
I wouldn't know a nano tooth from a toaster. I
got that from Dr. Bob...I have seen the photographs and the shape is
certainly different from Tinker's teeth.
Me
Do you agree with the concept of Tinker being incapable of hunting down it's
own meals and requiring to be fed by it's parents? As you say in your
response to the "evidence of feathers" post, Tinker is no baby and
represents what would amount to a four foot person. Humans have a long
dependancy period as it is, but up to that age? Okay, perhaps
rexes have a more accelerated growth rate and reach this size more swiftly than
people, but still - it's the same size as many an Allosaurid - how gangly does
it have to be for it not to be able to hunt it's own meals?
Mike
My personal thoughts unsupported by
any direct evidence: Tinker could probably hunt for himself and
undoubtedly did so. He could have certainly scavenged for himself. I
don't view Tinker's hunting as bringing down the big ones or even the
little ones who were healthy. Most predator attacks in the world today
end in failure...and this is for mature, seasoned hunters. Blundering
kids would have a...let's be generous...tough time bringing down
anything that was awake and able to move.
Tinker would have the raw power to deal with most anything. What he
couldn't have (my estimate here) is the coordination and prior knowledge
of 'what works' to actually fight something, particularly another
predator...think lion adolescent (or human) vs an experienced
adult...I'm thinking bloody and over quickly...in fact, it is possible
that this is what actually happened to Tinker...he squared off with one
or more Nanos and got his clock cleaned.
In conclusion I will be very interested in following the story of Tinker from it's sad beggining 65 million years ago to it's ressurection from the matrix and display in the present day. I will also be pursuing the "Is Nanotyrannus lancensis a juvenile T rex or not" argument and updating this page as Tinker divulges more information about his ancient life. What do you think, reader? I have enclosed a picture Mr Matheny sent me giving comparisons of some of the teeth found at the site. The top two bearing roots belong to Tinker and the bottom one is a shed tooth from a "Nano". Ultimately everything Mr Matheny or I tell you can only go so far - until such time as a full study has been done, it is up to you to make up your own mind on the matter. Look long and hard at those teeth ladies and gentlemen - the rest is up to you...
Pictures of some of the teeth found at the Tinker site
Other sites with relevant Tinker information
Dino Data's "News" section
Steve Brusatte's assessment of the find with more pictures