Jump to content

Recommended Posts

 Hi I decided to make a post about my main research project right now on Campanian Tyrannosaurs specifically Daspletosaurus. Today I have found something to tell teeth from the Judith River Formation and Dinosaur Park Formation. This could also do with the Tyrannosaurs prey or locality. I found out that Judith River Formation Tyrannosaur teeth serrations are more circular and more round compared to the same time Dinosaur Park Formation Tyrannosaur teeth serrations. The Dinosaur Park Formation Tyrannosaur teeth serrations are more longer skinner and more chiseled like but not like other Tyrannosaur teeth from other areas like T. rex’s teeth serrations. Certain Tyrannosaurs in different areas and times would/could of had unique serration morphology probably dew to there prey. I did this on multiple teeth from the Judith River Formation and Dinosaur Park Formation to strengthen my hypothesis. Any opinions on this topic would be great. I will post more on my research here on this and other topics on the Tyrannosaur/Daspletosaurus. I have been doing research on this Daspletosaurus from the Dinosaur Park Formation and it’s close relatives because it was the first dinosaur fossil I’ve ever found. I’ve liked fossils and dinosaurs since I was 2 but in 2018 I went to Alberta and found my first dinosaur fossil which was a fossil from the Dinosaur Park Formation Daspletosaurus sp. Thats why I have been researching on this topic. 

 

The serrations I found on Dinosaur Park Formation Tyrannosaur teeth.

C474E0FC-C32D-4BCD-AF29-F5EE94B42145.jpeg

 

The serrations I found on Judith River Formation Tyrannosaur teeth.

47B0733B-E13E-4FC9-97A3-1F420ED5172D.jpeg

  • I found this Informative 2
Link to comment
Share on other sites

2 hours ago, dinosaur man said:

Tyrannosaur teeth are more circular and more round compared to

Rounded, circular is more a feature of tooth position 

 

2 hours ago, dinosaur man said:

Tyrannosaur teeth are more longer skinner 

Dont understand what you are saying how can the length of tooth describe much other than position or age

  

  • I found this Informative 3
Link to comment
Share on other sites

46 minutes ago, Troodon said:

Rounded, circular is more a feature of tooth position 

 

Dont understand what you are saying how can the length of tooth describe much other than position or age

  

@Troodon Thank you!! But how come that none of the serrations I found on the Dinosaur Park Formation teeth, are not found on the Judith River Formation teeth?

 

Sorry i meant to say the serrations are longer and skinnier.

Link to comment
Share on other sites

3 minutes ago, Troodon said:

So you talking about denticle configurations  

Not teeth  ?  You have not been very clear

Yeah, sorry, I fixed it to make it clearer.

Link to comment
Share on other sites

 

So how many teeth did you use in your study from each locality and from what part if the jaw were these teeth from?  Did the denticles in  every tooth, from each locality,  have the same characteristics

  • I found this Informative 3
Link to comment
Share on other sites

23 minutes ago, Troodon said:

 

So how many teeth did you use in your study from each locality and from what part if the jaw were these teeth from?  Did the denticles in  every tooth, from each locality,  have the same characteristics

@Troodon I did it on 14 Dinosaur Park Formation teeth and and 20 Judith River Formation teeth so far. I’ve done some more research and found that Judith River Formation teeth also have chiseled shape serrations, but none that I have seen so far have the same shapes as the Dinosaur Park Formation teeth. There are two serrations types I’ve seen in the Dinosaur Park Formation teeth the one above and a rectangle one a chiseled shaped tooth but a fatter base. And two serrations types in the Judith River Formation the above one and the chiseled serrations. And all have been Maxillary teeth. 

  • I found this Informative 2
Link to comment
Share on other sites

A minor point but you are talking about denticle shape not serration shape.  Two very different features of a theropod tooth.

 

Sorry I'm lost

7 hours ago, dinosaur man said:

Judith River Formation teeth also have chiseled shape serrations, but none that I have seen so far have the same shapes as the Dinosaur Park Formation teeth.

Here you say JRF denticles are chisel shaped

7 hours ago, dinosaur man said:

And two serrations types in the Judith River Formation the above one and the chiseled serration

Here you say there are two types  JRF denticles, chisel shaped and the one above ..which is what?

 

Jaw position can influence the shape of denticles and you mention all your teeth have been Maxillary, might be why you see a difference,  I dont know..  Not that well versed on the variation of denticle shape.

 

I suggest you try to take photo's of your different shapes and email P. Currie and see what he says.  Now he is an expert.

 

Here is a paper that Im sure you've seen that discusses the morphology of Tyrannosaurid teeth in North America.  Most of the teeth studied are from Alberta's the Belly River Group that includes DPF.   The study includes denticle shape and variations in them but does not compare them to JRF teeth from Montana.    

 

https://www.app.pan.pl/article/item/app50-757.html

  • I found this Informative 4
Link to comment
Share on other sites

@Troodon Thank you!!, I will ask him. And the two types of Judith River Formation teeth serration types are, the the circular round ones from my 2nd drawing and the chiseled shape serrations.

  • I found this Informative 1
Link to comment
Share on other sites

Sounds like a great project dinosaur man! Always fun to work on stuff you’re passionate about :thumbsu:

 

Now that said, a key part of any scientific study is asking questions and ensuring logical, consistent methodology. So here are some questions that hopefully will give you some more things to think about and research.

 

14 hours ago, dinosaur man said:

 Hi I decided to make a post about my main research project right now on Campanian Tyrannosaurs specifically Daspletosaurus. Today I have found something to tell teeth from the Judith River Formation and Dinosaur Park Formation. Are these teeth specifically associated with Daspletosaurus body fossils, or are they isolated teeth? (Is there any definitive way to say they come from Daspletosaurus?) This could also do with the Tyrannosaurs prey or locality. How? What (or how) would Judith River tyrannosaurs be eating that Dinosaur Park tyrannosaurs wouldn’t be? I found out that Judith River Formation Tyrannosaur teeth serrations are more circular and more round compared to the same time Dinosaur Park Formation Tyrannosaur teeth serrations. The Dinosaur Park Formation Tyrannosaur teeth serrations are more longer skinner and more chiseled like but not like other Tyrannosaur teeth from other areas like T. rex’s teeth serrations.  Could this be the result of wear (i.e., small sample size bias) or tooth position?  Certain Tyrannosaurs in different areas and times would/could of I think you mean “could have had”, not “could of had” (sorry, not a scientific point but I’ve seen a lot of people on the internet write the wrong word in this phrase and don’t want you to be one of them :)) had unique serration morphology probably dew to there prey. Again, how would their diet influence denticle morphology? Do you have evidence suggesting preferred prey species for one tyrannosaur compared to another, or a specific example of this situation in another species (extinct or modern)? The issue here is less with the conclusion and more with it being unclear how you got to it. and I did this on multiple teeth from the Judith River Formation and Dinosaur Park Formation to strengthen my hypothesis. Good job, but how much is enough? Is an average of 17 teeth from each horizon enough to form a serious conclusion about location-specific morphologies when an individual tyrannosaur would have had more than 17 teeth in its mouth? Any opinions on this topic would be great. I will post more on my research here on this and other topics on the Tyrannosaur/Daspletosaurus. Please do! :)  have been doing research on this Daspletosaurus from the Dinosaur Park Formation and it’s close relatives because it was the first dinosaur fossil I’ve ever found. I’ve liked fossils and dinosaurs since I was 2 but in 2018 I went to Alberta and found my first dinosaur fossil which was a fossil from the Dinosaur Park Formation Daspletosaurus sp. Thats why I have been researching on this topic. 

 

The serrations I found on Dinosaur Park Formation Tyrannosaur teeth.

C474E0FC-C32D-4BCD-AF29-F5EE94B42145.jpeg

 

The serrations I found on Judith River Formation Tyrannosaur teeth.

47B0733B-E13E-4FC9-97A3-1F420ED5172D.jpeg 
Good, but you do have photographic examples of these morphologies? Photos are generally less subjective and will allow us to see what you’re seeing and comment more intelligently.

 

 

1 hour ago, dinosaur man said:

@Troodon Thank you!!, I will ask him. And the two types of Judith River Formation teeth serration types are, the the circular round ones from my 2nd drawing and the chiseled shape serrations.

Now hang on a second, wasn’t the entire point of your first post that the two different morphotypes you identified were stratigraphically separated (one only found in DPF, one in JRF)? It seems like you’re saying now that both are found in the JRF, which is the opposite of your original point and makes it unclear what you’re trying to say.

 

Looking forward to seeing what you come up with! Hopefully my comments are clear and give you a basis for further thought and research. :)

  • I found this Informative 5
Link to comment
Share on other sites

28 minutes ago, Arion said:

Sounds like a great project dinosaur man! Always fun to work on stuff you’re passionate about :thumbsu:

 

Now that said, a key part of any scientific study is asking questions and ensuring logical, consistent methodology. So here are some questions that hopefully will give you some more things to think about and research.

 

 

 

Now hang on a second, wasn’t the entire point of your first post that the two different morphotypes you identified were stratigraphically separated (one only found in DPF, one in JRF)? It seems like you’re saying now that both are found in the JRF, which is the opposite of your original point and makes it unclear what you’re trying to say.

 

Looking forward to seeing what you come up with! Hopefully my comments are clear and give you a basis for further thought and research. :)

@Arion Thank you for the questions!!, I have done more research on it and have found  TWO distinct serration types on both Dinosaur Park Formation and Judith River Formation. Again Thank you!!

Link to comment
Share on other sites

I have a new hypothesis that the top teeth serrations are Daspletosaurus and the bottom are Gorgosaurus. A possible way of telling Daspletosaurus from Gorgosaurus. I have found the same type of Daspletosaurus serrations in specimens of Daspletosaurus and I have found the same type of serrations I found one Gorgosaurus in Gorgosaurus specimens, from both Formations.

 

Daspletosaurus possibly had serrations like this and the chiseled serrations.

E49F0A3D-E1A2-4242-B609-7E6D222DC26A.jpeg

 

Gorgosaurus possibly had serrations like this and rectangular serrations.

BC4021E9-891A-4E49-BD17-D1DB101F4783.jpeg

Link to comment
Share on other sites

I have talk to Corwin Sullivab at the university of Alberta since Phill Currie was busy about the serrations. He said that it was definitely interesting but in order to prove it there would need to be a big systematic study on lots of teeth.

  • I found this Informative 3
Link to comment
Share on other sites

I have another the first skull is a reconstruction from the Dinosaur Park Formation Daspletosaurus sp. specimen FMNH PR308 skull. And the second is a reconstruction of the skull of the Tumbler Ridge Tyrannosaur. These photos are better then my photos from before. They look very similar. Any opinions would be great.

2E24D7BE-ED37-4CC1-80F5-5E42779D6A26.jpeg

ED51C13B-597D-4E29-8A84-FEB696EAC228.jpeg

Link to comment
Share on other sites

21 minutes ago, Randyw said:

They don’t look very similar to me. I see multiple differences between the 2

Agreed there are a lot differences but there are also a lot of similarities.

Link to comment
Share on other sites

Of course there are similarities they are images of tyrannosaurids but one cannot distinguish anything more from that black and grey sketch. The diagnostic elements are not shown.

  • I found this Informative 1
Link to comment
Share on other sites

43 minutes ago, dinosaur man said:

Agreed there are a lot differences but there are also a lot of similarities.

Repeatability is a crucial part of a strong scientific hypothesis, even in the sense of helping someone else to see how you got from A to C. That’s where citing specific anatomical features to support your ideas is really helpful, because it allows everyone else who isn’t inside your head to see your thought process and provides a testable and repeatable way to assess your conclusions.

 

So in this case, you suggest that the Tumbler Ridge tyrannosaur is similar to a skull of Daspletosaurus. Great! But...thinking they’re similar is a very subjective viewpoint, and as we’ve already seen it’s obviously not one shared by everyone. What you need is some objective characters that someone else can look at and assess for themselves. If you say, for example, ‘The height : length ratio of the maxilla is x:x in both, and and ascending ramus of the maxilla does not extend posteriorly beyond the posteriormost maxillary tooth,’ then there’s a couple of specific features we can look at and understand what you mean by saying they’re similar.

 

So I think the main issue is we can’t see how you got from A to C at this point. You’ve provided some evidence and offered an interpretation, but we’re not clear (or at least I’m not) on how you got to the conclusion from the stated evidence because it’s not obvious to us. Articulating your thought process will really help. :)

  • I found this Informative 5
Link to comment
Share on other sites

35 minutes ago, Arion said:

Repeatability is a crucial part of a strong scientific hypothesis, even in the sense of helping someone else to see how you got from A to C. That’s where citing specific anatomical features to support your ideas is really helpful, because it allows everyone else who isn’t inside your head to see your thought process and provides a testable and repeatable way to assess your conclusions.

 

So in this case, you suggest that the Tumbler Ridge tyrannosaur is similar to a skull of Daspletosaurus. Great! But...thinking they’re similar is a very subjective viewpoint, and as we’ve already seen it’s obviously not one shared by everyone. What you need is some objective characters that someone else can look at and assess for themselves. If you say, for example, ‘The height : length ratio of the maxilla is x:x in both, and and ascending ramus of the maxilla does not extend posteriorly beyond the posteriormost maxillary tooth,’ then there’s a couple of specific features we can look at and understand what you mean by saying they’re similar.

 

So I think the main issue is we can’t see how you got from A to C at this point. You’ve provided some evidence and offered an interpretation, but we’re not clear (or at least I’m not) on how you got to the conclusion from the stated evidence because it’s not obvious to us. Articulating your thought process will really help. :)

@Arion Thank you!! I’m going to start posting how I got my conclusions. Right now all my stuff is at home, but for now one thing is both the Tumbler Ridge Tyrannosaur and Dinosaur Park Formation Daspletosaurus sp. specimen FMNH PR308 have a maxilla height of around 25cm.

Link to comment
Share on other sites

This is my understanding of the TR Tyranno.

The only element found in the TR tyranno was the maxilla embedded in a rock slab see photo..  Additional prepping will be needed to really expose its features which then can be used in identification.   The other key data point which will aid in identification is to understand the age of deposit it was found in.   The rock slab was actually moved to the area about 14 years ago, likely after being extracted from a quarry in the region.  They believe it's late Campanian or early Maastrichtian but it needs to be quantified which would then would point to Albertosaurus, Daspletosaurus or Gorgosaurus.

 

bc_tyrannosaur_skull.jpg.534af3330f473f2558f5a7ad10097441.jpg

 

This image posted was not a reconstruction but just to show the public where the maxilla fits in the jaw

 

A diagram of a typical Tyrannosaur showing the location of the maxilla.

Tyrannosaurid-skull-outlineBC.jpg.8f9aac1e8a281c2e0f4cf205f341fe21.jpg

  • I found this Informative 4
Link to comment
Share on other sites

33 minutes ago, Troodon said:

This is my understanding of the TR Tyranno.

The only element found in the TR tyranno was the maxilla embedded in a rock slab see photo..  Additional prepping will be needed to really expose its features which then can be used in identification.   The other key data point which will aid in identification is to understand the age of deposit it was found in.   The rock slab was actually moved to the area about 14 years ago, likely after being extracted from a quarry in the region.  They believe it's late Campanian or early Maastrichtian but it needs to be quantified which would then would point to Albertosaurus, Daspletosaurus or Gorgosaurus.

 

bc_tyrannosaur_skull.jpg.534af3330f473f2558f5a7ad10097441.jpg

 

This image posted was not a reconstruction but just to show the public where the maxilla fits in the jaw

 

A diagram of a typical Tyrannosaur showing the location of the maxilla.

Tyrannosaurid-skull-outlineBC.jpg.8f9aac1e8a281c2e0f4cf205f341fe21.jpg

Ahh, but I have still found similarities between the original maxilla and Daspletosaurus sp. And also they have found Tyrannosaur teeth in the area.

Link to comment
Share on other sites

When it comes to fossils everyone is entitled to opinions and best when they are supported with concrete facts that are clear and well defined.  Yes teeth and even tracks have been been found in the area and I all point to the same three possible Tyrannosaurids.

  • I found this Informative 5
Link to comment
Share on other sites

8 minutes ago, dinosaur man said:

Ahh, but I have still found similarities between the original maxilla and Daspletosaurus sp. And also they have found Tyrannosaur teeth in the area.

 

As has been stated, you need to remember those similarities and differences must be quantifiable.

  • I found this Informative 3

The human mind has the ability to believe anything is true.  -  JJ

Link to comment
Share on other sites

3 hours ago, Troodon said:

This is my understanding of the TR Tyranno.

The only element found in the TR tyranno was the maxilla embedded in a rock slab see photo..  Additional prepping will be needed to really expose its features which then can be used in identification.   The other key data point which will aid in identification is to understand the age of deposit it was found in.   The rock slab was actually moved to the area about 14 years ago, likely after being extracted from a quarry in the region.  They believe it's late Campanian or early Maastrichtian but it needs to be quantified which would then would point to Albertosaurus, Daspletosaurus or Gorgosaurus.

 

bc_tyrannosaur_skull.jpg.534af3330f473f2558f5a7ad10097441.jpg

 

This image posted was not a reconstruction but just to show the public where the maxilla fits in the jaw

 

A diagram of a typical Tyrannosaur showing the location of the maxilla.

Tyrannosaurid-skull-outlineBC.jpg.8f9aac1e8a281c2e0f4cf205f341fe21.jpg

@Troodon it might be a reconstruction. Do to what the maxilla looks like in the photo has a very close look to the real thing. And I found this. 

D27D0689-477B-405C-AE3F-7EB762785722.jpeg

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...