My Jurassic Park: Hell Creek/lance Theropods

[Troodon]

@Bone guy @-Andy- @Tidgy's Dad @Bobby Rico @Jaimin013

Thank you,   definitely  3 love faces Bobby

 

@Haravex

Thanks, No idea what that scar is.  Will show Pete Larsen at next years tucson show and get his thoughts

[TyBoy]

Wow that an unmistakable Rex tooth, nice, very nice

[Troodon]

@StevenJD  @TyBoy

 

Thank you

[Troodon]

Nanotyrannus tooth with what appears to be pathology in the tip area

 

 

Nanotyrannus Tooth

 

Nanotyrannus Tooth

 

[Troodon]

 

[-Andy-]

How did you differentiate this from a T. rex foot claw?

[Troodon]

1 hour ago, -Andy- said:

How did you differentiate this from a T. rex foot claw?

Just size and it matches the claws on the dueling Dino Nano.  I don't buy comments that say it would be a juvie rex.  Pete Larsen may be able to tell them apart.  

[Troodon]

A few Dromaeosaurid teeth I decided to post.   

Acheroraptor temertyorum is the small Dromaeosaurid in the Hell Creek

 

Lateral tooth:

 

 

 

Premaxillary tooth:

This morphology was for many years assigned to Zapsalis sp. however a 2019 paper identified it as a Dromaeosaurid premaxillary tooth of Saurorintholestes langstoni in the Dinosaur Park Fm.   The authors of the paper believe that this morphology in the Hell Creek/Lance most likely belongs to Acheroraptor since the teeth are very similar.

 

 

 

@JoeS First I want to thank you since your recent posts stimulated me to take a look at a couple of my Acheroraptor teeth especially the last one.   Its the size of this tooth why I was thinking yours was Nanotyrannus.  Its characteristics are identical to yours but at 2 cm high significantly larger than yours.  I wrote to Phil to get his thoughts on it and how it compared to the ones in Saurornitholestes skull they have.  Well the largest dentary tooth in that skull is only 12 mm.   Phil still is betting on it being Acheroraptor but like anything different its needs additional specimens to be conclusive.  Lots of unknowns, even the existence of Dakotaraptor is questioned by several notable paleontologists, most say more conclusive specimens are needed.

 

 

 

[JoeS]

14 hours ago, Troodon said:

A few Dromaeosaurid teeth I decided to post.   

Beautiful teeth! Never seen a rooted Acheroraptor   Thanks for sharing!
That anterior dentary is super and indeed huge, is the distal carina running straight down? I have a similar sized tooth from that same position, which lacks the typical Acheroraptor ridges. Was always entertaining the idea it might be a Dakotaraptor, but since we also lack an understanding of how these anterior teeth look in Nanotyrannus I guess we have to wait for new publications.
 

15 hours ago, Troodon said:

even the existence of Dakotaraptor is questioned by several notable paleontologists

Oh wow, how interesting, this is completely new to me, is there a blog or something I can read further? I only read that one of the bones in the publication was wrongfully assigned to Dakotaraptor at the time.

[Troodon]

On 2/7/2021 at 10:22 AM, JoeS said:

 

Oh wow, how interesting, this is completely new to me, is there a blog or something I can read further? I only read that one of the bones in the publication was wrongfully assigned to Dakotaraptor at the time.

Thanks

Here is the paper on the turtle bone

Dakotaraptor Furc.pdf

 

Other than email most of the discussions have been on Twitter where I saw this:

A tibia that looks like an Anzu.  Concern was that the locality contained multiple species.   

 

I think for those on the fence want to see additional material to confirm what has been described.   The digt II claw is definitely unique and distinctive 

 

On the tooth the distal is pretty straight, slight curvature.  I have a number of Nano teeth that look like this but they have worn serrations on the mesial edge.  Lots of unknowns because lots of these teeth have Densities greater than 1

 

Quick phone image

[Troodon]

Tooth that has been in my collection just getting around to properly identify it.

 

 

 

[Nanotyrannus35]

Looking at this topic is really awesome! Seeing all those teeth it's like tyrannosaur teeth are a dime a dozen.

[Troodon]

28 minutes ago, Nanotyrannus35 said:

Looking at this topic is really awesome! Seeing all those teeth it's like tyrannosaur teeth are a dime a dozen.

Thank you.  In the channel deposits that I've collected the most common dino teeth found are 1) Ceratopsian spitters  2) Nanotyrannus.    All about location, they are all different.

[Nanotyrannus35]

3 minutes ago, Troodon said:

In the channel deposits that I've collected the most common dino teeth found are 1) Ceratopsian spitters  2) Nanotyrannus.   

I think that Nanotyrannus teeth are the best. First off, they're smooth and elegant as opposed to big, thick Tyrannosaurus teeth, and second off, their a lot cheaper on the market than T. Rex teeth probably because less people know about the species.

[Troodon]

6 minutes ago, Nanotyrannus35 said:

I think that Nanotyrannus teeth are the best. First off, they're smooth and elegant as opposed to big, thick Tyrannosaurus teeth, and second off, their a lot cheaper on the market than T. Rex teeth probably because less people know about the species.

A LOT cheaper to acquire is right on 

[Nanotyrannus35]

2 minutes ago, Troodon said:

A LOT cheaper to acquire is right on 

Looking on the auction website I've noticed that a 1 inch Nanotyrannus tooth goes from 100-300 dollars while a 1 inch Tyrannosaurus tooth goes from 500-1000 dollars.

[-Andy-]

On 2/7/2021 at 9:54 AM, Troodon said:

Premaxillary tooth:

This morphology was for many years assigned to Zapsalis sp. however a 2019 paper identified it as a Dromaeosaurid premaxillary tooth of Saurorintholestes langstoni in the Dinosaur Park Fm.   The authors of the paper believe that this morphology in the Hell Creek/Lance most likely belongs to Acheroraptor since the teeth are very similar.

 

Hi Frank, I believe that Zapsalis sp. still exists in the Hell Creek/Lance Formation. I was reading this paper linked by you where the Saurornitholestes jaw was described > Cranial Anatomy of New Specimens of Saurornitholestes langstoni (Dinosauria, Theropoda, Dromaeosauridae) from the Dinosaur Park Formation (Campanian) of Alberta - Currie - 2020 - The Anatomical Record - Wiley Online Library

 

There was something interesting they mentioned:

Although Larson and Currie (2013) opinioned that the species from the Dinosaur Park Formation is equivalent to Z. abradens, the specimens recovered from Dinosaur Provincial Park have mesial denticles. Although it is possible that the holotype of Z. abradens from Montana had serrations that were lost because of tooth wear, the “roots” of serrations (Abler, 1992, fig. 13) are usually visible in worn teeth (such as the distal denticles of the holotype Zapsalis; Fig. 18A). This suggests that the holotype of Zapsalis, unlike Saurornitholestes might not have had mesial denticles. Many of the cf. Zapsalis teeth recovered from the Milk River Formation (Larson and Currie, 2013) include ones that lack mesial serrations. Furthermore, the distal margins of the teeth are concave in outline when viewed in lateral view, which also seems to be the case in the holotype of Zapsalis (AMNH FARB 3853). The similarity between the premaxillary teeth of Saurornitholestes and Zapsalis shows that the latter is a dromaeosaurid and suggests that the two genera may by synonymous. However, the differences suggest they are distinct at least at the species level. Pending the discovery of associated skeletal material from the Judith River Formation of Montana, it is recommended that the two genera be kept separate.

 

More surprising is the presence of a highly specialized second premaxillary tooth that is consistently flat and ridged on the lingual surface. These teeth were originally described as isolated elements by Cope (1876a, 1876b) as Z. abradens. Although distinct from Saurornitholestes at the species level, it is conceivable that the discovery of better preserved skeletal material in the Judith River Formation of Montana could lead to the synonymy of Saurornitholestes and Zapsalis. The second premaxillary teeth of at least Bambiraptor, Saurornitholestes, and Velociraptor may have been specialized for preening feathers.

 

This would indicate to me that while Zapsalis teeth are undoubtedly the premaxillary teeth of dromaeosaurid, the ones that lack mesial serration should still be identified as Zapsalis/Dromaeosaurid indet. for now until we are sure which dromaeosaurid species they belong to

[Troodon]

@-Andy-  .. That's the problem you have with Tooth taxons, its a bad way to describe any species.   Its a very good point you raise but not sure how it can be validated.   We just don't know what the anterior dentition of Dakotaraptor and Acheroraptor look like or even Zapsalis.  Lets take Acheroraptor, the premaxillary teeth on some could be serrated while others non-serrated so they may not be consisted animal to animal.  I say that because if you look at dromaeosaurid teeth from the same species you see some with lightly serrated mesial edges and other are smooth.  We also have little other evidence in the HC that there is a third Acheroraptor sized dromaeosaurid.   Where are the small dentary or maxillary Acheroraptor sized teeth?   Anyway Its going to take new discoveries to definitively make this call.   I lean right now toward only just having a small and large Dromaeosaurid (other than microraptors) in these deposits which is consistent with what you see in other faunas and the lower diversity of species in the HC/Lance formations. 

 

My tooth from Montana has mesial serrations so in my mind its Acheroraptor, so I'm satisfied.. 

[FB003]

@TroodonFinally got around to taking a look at these and I have to say they are all quite beautiful.  From what I can tell, the majority of these were collected personally which is even cooler in my opinion.  Is most of your overall collection collected by you?

Edited November 29, 2021 by FB003

[Troodon]

2 hours ago, FB003 said:

@TroodonFinally got around to taking a look at these and I have to say they are all quite beautiful.  From what I can tell, the majority of these were collected personally which is even cooler in my opinion.  Is most of your overall collection collected by you?

Thanks and no far from collecting it all.  I have collected mainly in the Hell Creek/Lance Fm and occasionally in the Judith, TwoMed

so thats were you would find a portion that is self collected material and some acquired.  The rest of my collection guessing 50% is all acquired.   

 

[FB003]

8 minutes ago, Troodon said:

Thanks and no far from collecting it all.  I have collected mainly in the Hell Creek/Lance Fm and occasionally in the Judith, TwoMed

so thats were you would find a portion that is self collected material and some acquired.  The rest of my collection guessing 50% is all acquired.   

 

Ah got it.  Thats still quite a large ratio.  Sounds like a fun time! Thank you for indulging my curiosity.  

[Troodon]

With the Tucson show I have access to some very knowledgeable individuals like Pete Larsen and always use that opportunity to ID material...   I had this pretty complete cervical vertebra for a while, still needs a little cleaning, and tentatively ID it as Anzu but wanted to get an expert opinion.   Pete looked at it and said it could only be Nanotyrannus.  Anzu cervicals are very pneumatic and super fragile and do not preserve very well.   He indicated that Nanotyrannus cervicals are very distinctive from T rex and are another characteristic that distinguishes the two species.   The lack of sutures points to it being an adult.   Super pumped when I heard that ID.

 

 

I showed him this bone and he said in all the years collecting had never seen any texture like this one.   Could be bird or Theropod but did not know.  Indicated it was the coolest specimen he's seen at the show. 

 

 

 

Finally, I showed him this tiny claw and wanted to confirm my call of a small Caenagnathid.   He agreed and is planning to send photo to Dave Evans since they have a tiny Hell Creek Caenagnathid at the ROM which they are studying.

 

[Fossil Collect]

On 9/7/2015 at 8:37 AM, Troodon said:

There are two Tyrannosaurs described in the Hell Creek & Lance Formations, Tyrannosaurus rex and Nanotyrannus lancensis. Teeth from these animals are the number one sought after and coveted item by collectors. I don't understand all the hoopla and prices they command since my friends who I collect with know that I'm not a tooth person and prefer bones and claws. However I've been fortunate to find and acquire a few teeth and will post a several of my nicer ones.

My two most favorite T-rex teeth are my biggest and smallest:

The Baby (one of the rarest teeth around) is 1 1/8" and when I showed it to Bob Bakkar and Pete Larson they flipped and never had seen a Rex tooth so small and confirmed it was one. Collected from Garfield County, MT.

My big Trex one is a rooted Premaxillary tooth at 6". One can see the replacement tooth hole at the bottom of the root

T-rex teeth are big and my biggest crown, no root still on the matrix is this 4 5/8" monster.

If your are interested none of these teeth have any work done to them. Minor crackfill to the root of the 6" tooth. Serrations are in pretty good shape.

.

Is it really a infant tooth or is it a juvenile?

[Troodon]

7 hours ago, Fossil Collect said:

Is it really a infant tooth or is it a juvenile?

Not sure exactly what you are referring to but if the question relates to the 1 1/4" tooth all I can say is that Bakker and Larsen both described it as a baby tooth after they examined it.  Proper age classification is " young" not "juvenile" (Hone et al. 2020)

[rocket]

On 2/7/2023 at 9:53 PM, Troodon said:

 

I showed him this bone and he said in all the years collecting had never seen any texture like this one.   Could be bird or Theropod but did not know.  Indicated it was the coolest specimen he's seen at the show. 

 

 

 

looks eroded for me, what do you think? 

Could you see if it is a "massive bone" or a hollow bone? For the first moment I thought about a ptero, but the second says might be not.

Very unusual bone, when Pete does not know it is really special