My Tyrannosaur research

[dinosaur man]

22 minutes ago, Runner64 said:

Hi @dinosaur man a very cool project you’re working on and am looking forward to looking at results. I’m glad you found something you’re passionate about!  

Thank you!!

[DPS Ammonite]

@dinosaur man  Have you joined a local paleontological society or volunteered at a paleo museum? Both of those places would help you with your interests and might help you with your research.

[dinosaur man]

4 hours ago, DPS Ammonite said:

@dinosaur man  Have you joined a local paleontological society or volunteered at a paleo museum? Both of those places would help you with your interests and might help you with your research.

Thank you for suggesting that!! But no I haven’t yet, I haven’t been able to find any in my area for some reason, considering my area is rich in Devonian and Silurian marine invertebrate fossils.

[Arion]

On 2/20/2020 at 3:30 PM, 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.

 

 

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.

A couple of things stand out to me about this. First, it looks very much like the maxilla is exposed in medial view, so any comparison with a picture of a maxilla in lateral view is unlikely to be super useful beyond a general outline.

 

Secondly I don’t think the interpretive drawing is intended to be anything more than what @Troodon says, a reconstruction to show where the maxilla fits in the skull. And even there, one could argue the proportions are a little off and the maxilla is positioned slightly more posteriorly than it should be.

 

I think until you give us some specific examples of the similarities with Daspletosaurus you’re seeing it’s hard for us to see this from your perspective; personally I think it could just as easily belong to Gorgosaurus, Albertosaurus, or a new genus, and especially until the stratigraphy gets resolved it’s pretty much impossible to say because the stratigraphic horizon is crucial to identification.

[dinosaur man]

Philip Currie has emailed me back about the Tyrannosaur serrations. And has said that there is a way to indentify some Daspletosaurus teeth. Quoted from him “We have one type of serrations with large arcuate ‘wrinkles’ on the inside of the tooth next tot the serrations. When we see these in Dinosaur Provincial Park, then we know we have a Daspletosaurus tooth. If the arcuate wrinkles are not there, however, then the tooth can still be from Daspletosaurus, or it can be from Gorgosaurus. So at least we are part-way there.” And he also said “Possibly you have found a way to identify at least some of the Gorgosaurus teeth.” 

[dinosaur man]

I have found out that the Dinosaur Park Formation Daspletosaurus May have migrated as the Western Interior Seaway moved West. Which is why there is the possibility of the Tumbler Ridge Tyrannosaur being a Daspletosaurus (which currently I’m trying to get more compelling evidence for, if so this could also strengthen this theory) as the the diagram below shows. It also could mean that any deposits in Alberta, Saskatchewan and British Columbia that are around 76.5 to 71 million years could contain this species.

[Arion]

3 hours ago, dinosaur man said:

I have found out that the Dinosaur Park Formation Daspletosaurus May have migrated as the Western Interior Seaway moved West. Which is why there is the possibility of the Tumbler Ridge Tyrannosaur being a Daspletosaurus (which currently I’m trying to get more compelling evidence for, if so this could also strengthen this theory) as the the diagram below shows. It also could mean that any deposits in Alberta, Saskatchewan and British Columbia that are around 76.5 to 71 million years could contain this species.

Interesting idea; what’s the basis for this theory?

[dinosaur man]

10 hours ago, Arion said:

Interesting idea; what’s the basis for this theory?

@Arion my evidence is this: there is a lot of evidence on Daspletosaurus being present in the Horseshoe Canyon Formation like:

 

From specimen CMN 11315 

-The same dentary width as Daspletosaurus.

-That the transition between the rostral and ventral margins of the dentary occurs below the first and second alveolus as in Daspletosaurus.

-The proximal face of the femur is straight and oriented at a obtuse angle to the long axis of the shaft which indicates Daspletosaurus. 

-The foramen is distinct from the quadratojugal pheumatopore as in Daspletosaurus.

-And there are similarities with Albertosaurus but that just might be dew to that the animals not fully grown.

 

As this is all from the only Horseshoe Canyon Formation possible Daspletosaurus specimen it most likely is Daspletosaurus. Also before the Horseshoe Canyon Formation  the only Daspletosaurus fossils where found more East of this and the closest in time to this specimen is the Dinosaur Park Formation Daspletosaurus sp. it could show that the Dinosaur Park Formation Daspletosaurus and other dinosaurs of it area moved West as the Western Interior Seaway moved West. Which also means there’s a possibility of the Tumbler Ridge Tyrannosaur is the Daspletosaurus sp. as so with the possibility some of the Pipestone Creek areas Tyrannosaurs could be Daspletosaurus sp. when it moved even further West. Also at this time I believe that the Gorgosaurus evolved to the Albertosaurus at about 74 million years ago to adapt with everything that was happening at the time.

[connorp]

1 hour ago, dinosaur man said:

Also at this time I believe that the Gorgosaurus evolved to the Albertosaurus at about 74 million years ago to adapt with everything that was happening at the time.

I don’t follow this. Wikipedia states that “Gorgosaurus and Albertosaurus are extremely similar, distinguished mainly by subtle differences in the teeth and skull bones.” I assume by “everything that was happening,” you’re referring primarily to the marine transgression. I don’t see how slight morphological changes in the skull and dentition would lead to an evolutionary advantage with rising sea levels.

 

Furthermore, I don’t believe there is a clear consensus on whether G. libratus is actually a species of Albertosaurus or not. So it’s hard to say one genus evolved into the other if it’s not clear they’re even separate genera. 

[Troodon]

7 hours ago, dinosaur man said:

evidence is this: there is a lot of evidence on Daspletosaurus being present in the Horseshoe Canyon Formation like:

 

From specimen CMN 11315

@connorp @Arion

I refer you to a VERY recent publication, 2019, by notable paleontologists Phil Currie, Jordan Mallon et al. ..

 

They make the following statement:

 

"To date, A. sarcophagus remains the only unequivocally identified tyrannosaurid species from the Horseshoe Canyon Formation (Carr, 2010; Eberth et al., 2013). Daspletosaurus spp. are otherwise known only from the older Dinosaur Park, Oldman, and Two Medicine formations (Currie, 2005; Carr et al., 2017). The presence of Daspletosaurus sp. as a second tyrannosaurid in the Horseshoe Canyon Formation, although not unprecedented (both Daspletosaurus sp.and Gorgosaurus libratus are present in the Dinosaur Park Formation; Farlow and Planka, 2002), requires more compelling evidence than that provided by Russell (1970), ideally in the form of a mature individual. Therefore, we consider the weight of the evidence, particularly the cladistic and biostratigraphic considerations, to favor the hypothesis that CMN 11315 represents an immature A. sarcophagus.

 

https://anatomypubs.onlinelibrary.wiley.com/doi/10.1002/ar.24199

 

 

We also have this paper that clearly makes the following statement:

 

"Also, in western Canada these tyrannosaurid taxa are temporally separated: G. libratus and D. torosus are reported from deposits that are middle to late Campanian in age, whereas A. sarcophagus is reported from late Campanian to Maastrichtian deposits."

 

Publication:

Quantifying tooth variation within a single population of Albertosaurus sarcophagus (Theropoda: Tyrannosauridae) and implications for identifying isolated teeth of tyrannosaurids. 

 

By Lisa G. Buckley, Derek W. Larson, Miriam Reichel, and Tanya Samman

 

Let me add: 

Why it's also very important to understand the age of the TR Tyranno before trying to assign it to any specific genus/species

[dinosaur man]

1 hour ago, Troodon said:

@connorp @Arion

I refer you to a VERY recent publication, 2019, by notable paleontologists Phil Currie, Jordan Mallon et al. ..

 

They make the following statement:

 

"To date, A. sarcophagus remains the only unequivocally identified tyrannosaurid species from the Horseshoe Canyon Formation (Carr, 2010; Eberth et al., 2013). Daspletosaurus spp. are otherwise known only from the older Dinosaur Park, Oldman, and Two Medicine formations (Currie, 2005; Carr et al., 2017). The presence of Daspletosaurus sp. as a second tyrannosaurid in the Horseshoe Canyon Formation, although not unprecedented (both Daspletosaurus sp.and Gorgosaurus libratus are present in the Dinosaur Park Formation; Farlow and Planka, 2002), requires more compelling evidence than that provided by Russell (1970), ideally in the form of a mature individual. Therefore, we consider the weight of the evidence, particularly the cladistic and biostratigraphic considerations, to favor the hypothesis that CMN 11315 represents an immature A. sarcophagus.

 

https://anatomypubs.onlinelibrary.wiley.com/doi/10.1002/ar.24199

 

 

We also have this paper that clearly makes the following statement:

 

"Also, in western Canada these tyrannosaurid taxa are temporally separated: G. libratus and D. torosus are reported from deposits that are middle to late Campanian in age, whereas A. sarcophagus is reported from late Campanian to Maastrichtian deposits."

 

Publication:

Quantifying tooth variation within a single population of Albertosaurus sarcophagus (Theropoda: Tyrannosauridae) and implications for identifying isolated teeth of tyrannosaurids. 

 

By Lisa G. Buckley, Derek W. Larson, Miriam Reichel, and Tanya Samman

 

Let me add: 

Why it's also very important to understand the age of the TR Tyranno before trying to assign it to any specific genus/species

@Troodon the paper on Thanatotherises says that there is a possibility of identifiable Daspletosaurus specimens being found in the Horseshoe Canyon Formation. But for right now none  have been found. They said that it was probably present where most people thought that it went extinct before then. And I know the age of the TR Tyrannosaur but Daspletosaurus was known to possibly live at this time as the above paper states.

[TyBoy]

35 minutes ago, dinosaur man said:

But for right now none  have been found

If you knew this to be true why did you make the comment above " my evidence is this: there is a lot of evidence on Daspletosaurus being present in the Horseshoe Canyon Formation"   

 

Sure lots possibilities are out there but that's all they are possibilities and we need to deal in facts...

 

41 minutes ago, dinosaur man said:

And I know the age of the TR Tyrannosaur 

So what is it and the documentation to support it?

[Arion]

9 hours ago, dinosaur man said:

@Arion my evidence is this: there is a lot of evidence on Daspletosaurus being present in the Horseshoe Canyon Formation like:

 

From specimen CMN 11315 

-The same dentary width as Daspletosaurus.

-That the transition between the rostral and ventral margins of the dentary occurs below the first and second alveolus as in Daspletosaurus.

-The proximal face of the femur is straight and oriented at a obtuse angle to the long axis of the shaft which indicates Daspletosaurus. 

-The foramen is distinct from the quadratojugal pheumatopore as in Daspletosaurus.

-And there are similarities with Albertosaurus but that just might be dew to that the animals not fully grown.

 

Excellent! This is the kind of qualitative information I was looking for.  

 

Here are my observations. My experience with this specimen comes from Mallon et al. (2019), referenced by @Troodon earlier in this thread.

 

9 hours ago, dinosaur man said:

-The same dentary width as Daspletosaurus.

Absolute measurements are rarely useful as a diagnostic feature in dinosaur fossils, and especially so in this case since CMN 11315 is an immature individual. (To illustrate this with a silly example, suppose we were to say that because Gorgosaurus from the Dinosaur Park Formation had a skull X centimetres long, all tyrannosaurs from the DPF with skulls X centimetres long were Gorgosaurus. But if an adult Daspletosaurus from the DPF had a skull X+15 centimetres long, then obviously at some point in its life a slightly younger Daspletosaurus also would have had a skull X centimetres long, growing the extra 15 centimetres as it matured. So using absolute size as a way to identify Gorgosaurus in this example does not work).

 

9 hours ago, dinosaur man said:

-That the transition between the rostral and ventral margins of the dentary occurs below the first and second alveolus as in Daspletosaurus.

I'll give you that one; Mallon et al. (2019) agree on this feature.

 

9 hours ago, dinosaur man said:

-The proximal face of the femur is straight and oriented at a obtuse angle to the long axis of the shaft which indicates Daspletosaurus. 

Mallon et al. (2019) note, "The proximal face of the femur is straight and oriented at an obtuse angle to the long axis of the shaft (i.e., dorsally or proximally inclined head), which contrasts with the condition in D. torosus and Ty. rex, in which this surface is concave (Brusatte and Carr, 2016)."  So this actually would indicate that CMN 11315 is not Daspletosaurus, in which the proximal face of the femur is concave, not straight.

 

9 hours ago, dinosaur man said:

-The foramen is distinct from the quadratojugal pheumatopore as in Daspletosaurus.

Again, Mallon et al. (2019) note, "There is a small (∼4 mm) foramen that perforates the center of the fossa on the dorsal process. This foramen has not been described elsewhere in a tyrannosaurid, but it is variably present in Albertosaurus sarcophagus (present: TMP 1981.010.0001, TMP 1985.098.0001; absent: TMP 1998.063.0084). The foramen is distinct from the quadratojugal pneumatopore seen in Daspletosaurus horneri and Nanotyrannus lancensis, which occurs lower on the lateral surface of the dorsal process, beyond the bounds of the fossa (Larson, 2013; Carr et al., 2017)." So Daspletosaurus does not have a foramen on the dorsal process of the quadratojugal, it has a pneumatopore lower on the lateral surface of the dorsal process outside of the fossa. Their point is that this is a feature that has been observed in Albertosaurus but not Daspletosaurus.

 

9 hours ago, dinosaur man said:

 

-And there are similarities with Albertosaurus but that just might be dew to that the animals not fully grown.

By the same logic, might the similarities you see with Daspletosaurus also be due to CMN 11315 being immature?

 

9 hours ago, dinosaur man said:

Also before the Horseshoe Canyon Formation  the only Daspletosaurus fossils where found more East of this and the closest in time to this specimen is the Dinosaur Park Formation Daspletosaurus sp. it could show that the Dinosaur Park Formation Daspletosaurus and other dinosaurs of it area moved West as the Western Interior Seaway moved West. Which also means there’s a possibility of the Tumbler Ridge Tyrannosaur is the Daspletosaurus sp. as so with the possibility some of the Pipestone Creek areas Tyrannosaurs could be Daspletosaurus sp. when it moved even further West. Also at this time I believe that the Gorgosaurus evolved to the Albertosaurus at about 74 million years ago to adapt with everything that was happening at the time.

Technically it is true that exposures of the Dinosaur Park Formation are more southeast than the Horseshoe Canyon Formation, but it's hard to make a direct connection between that and the life ranges of the fauna those formations preserve. The interior seaway was closing as the Cretaceous period concluded, not opening, and the presence of younger terrestrial strata farther east in Canada (i.e., Frenchman Formation in Saskatchewan) would suggest to me that it was not moving west at this time.

 

I think Mallon et al. (2019), cited by @Troodon, is an excellent study of CMN 11315. They found that "CMN 11315 represents an immature A. sarcophagus. Any morphometric similarity to Daspletosaurus spp. is attributable to convergent intraspecific variation." They also found that "Notably, CMN 11315 shares several skull characters (which are often considered the most useful for taxonomic identification; Currie et al., 2003) with A. sarcophagus, to the exclusion of tyrannosaurines. It shares only one (transition between the rostral and ventral margins of the dentary occurs below the first and second alveolus) with Daspletosaurus spp., to the exclusion of albertosaurines." Throughout the paper they cite a number of features that are shared by CMN 11315 and albertosaurines but not with Daspletosaurus. Their conclusion is that CMN 11315 is not even from the same subfamily as Daspletosaurus. It's simpler to conclude that CMN 11315 is Albertosaurus (a well-documented tyrannosaur from the same formation with which it shares a number of features) than Daspletosaurus (which is several million years older, from different formations, and from which CMN 11315 differs in many ways).

 

3 hours ago, Troodon said:

We also have this paper that clearly makes the following statement:

 

"Also, in western Canada these tyrannosaurid taxa are temporally separated: G. libratus and D. torosus are reported from deposits that are middle to late Campanian in age, whereas A. sarcophagus is reported from late Campanian to Maastrichtian deposits."

 

Publication:

Quantifying tooth variation within a single population of Albertosaurus sarcophagus (Theropoda: Tyrannosauridae) and implications for identifying isolated teeth of tyrannosaurids. 

 

By Lisa G. Buckley, Derek W. Larson, Miriam Reichel, and Tanya Samman

 

Let me add: 

Why it's also very important to understand the age of the TR Tyranno before trying to assign it to any specific genus/species

Ornithischian dinosaurs from Late Cretaceous of western North America also seem to have had very specific chronologic and geographic ranges (see the chronological succession of ankylosaurs in Alberta during the Campanian, as an example). Also in Alberta we have Thanatotheristes, which lived only a couple million years before Daspletosaurus and Gorgosaurus, underscoring the importance of a precise age for the Tumbler Ridge tyrannosaur in assisting with identification. A quick Macrostrat search in the area around Tumbler Ridge, including surrounding areas where the fossil may have originally come from, shows strata ranging from Albian-Maastrichtian in age, so that doesn't narrow it down much.

[dinosaur man]

@Arion I have heard that the Tumbler Ridge Tyrannosaur is 74-72 MYA. But also CNN 11315 may not be Daspletosaurus but in some papers I have seen they say that Daspletosaurus might one day be found there so there is still a big possibility of Daspletosaurus being present in the Horseshoe Canyon Formation. And the Seaway was moving West until about 72 million years ago where it slowly moved back few to changes and was almost all gone at about 68 million years ago. And Thank you!!

 

@TyBoy I was talking about identifiable Daspletosaurus material which could easily  tell that it’s Daspletosaurus. Not like CMN 11315 which is now most likely known as Albertosaurus but at the time was not fully identifiable. 

[TyBoy]

1 hour ago, dinosaur man said:

 I was talking about identifiable Daspletosaurus material which could easily  tell that it’s Daspletosaurus. Not like CMN 11315 which is now most likely known as Albertosaurus but at the time was fully identifiable. 

 

No you said there are lots of examples to show that Daspletosaurus was present in the HCF and cited several examples in  CMN 11315 to prove your point.  Yet the same paper you obtained your info from said it was Albertosaurus.   

My other point was the age of TR Tyranno where you said I knew the date.. Now you are saying I heard of a date range...Knowing and Hearing are two different things..

 

 

 

[dinosaur man]

47 minutes ago, TyBoy said:

 

No you said there are lots of examples to show that Daspletosaurus was present in the HCF and cited several examples in  CMN 11315 to prove your point.  Yet the same paper you obtained your info from said it was Albertosaurus.   

My other point was the age of TR Tyranno where you said I knew the date.. Now you are saying I heard of a date range...Knowing and Hearing are two different things..

 

 

 

Yeah because in the paper it said it was most likely Albertosaurus which doesn’t mean definitely an Albertosaurus. And sorry I knew the age range was 74-72 million years ago.

[Troodon]

Part of research is dealing with facts and not letting personal biases, wishes, desires enter into the equation.  The paper said clearly A. sarcophagus remains the only unequivocally identified tyrannosaurid species from the Horseshoe Canyon Formation.   Challenging accepted hypotheses is good but biasing everything you read toward your desires is not.

 

 I'm very curious you keep saying you know the age of the TR tyranno to be 74-72 what is your source?  

[dinosaur man]

13 minutes ago, Troodon said:

Part of research is dealing with facts and not letting personal biases, wishes, desires enter into the equation.  The paper said clearly A. sarcophagus remains the only unequivocally identified tyrannosaurid species from the Horseshoe Canyon Formation.   Challenging accepted hypotheses is good but biasing everything you read toward your desires is not.

 

 I'm very curious you keep saying you know the age of the TR tyranno to be 74-72 what is your source?  

My sources for the age of the Tumbler Ridge Tyrannosaur is some news websites, and also this

https://www.trmf.ca/prprc#palaeontologist-contact.

[Kane]

13 minutes ago, dinosaur man said:

My sources for the age of the Tumbler Ridge Tyrannosaur is some news websites, and also this

https://www.trmf.ca/prprc#palaeontologist-contact.

News websites are not peer reviewed scholarly publications. More often than not, news articles misconstrue, bowdlerize, oversimplify, or even wilfully distort and sensationalize scholarly research in order to gain readership / clicks. 

 

When searching and citing information, confirmation through scholarly peer-reviewed sources is the gold standard.  

[dinosaur man]

6 minutes ago, Kane said:

News websites are not peer reviewed scholarly publications. More often than not, news articles misconstrue, bowdlerize, oversimplify, or even wilfully distort and sensationalize scholarly research in order to gain readership / clicks. 

 

When searching and citing information, confirmation through scholarly peer-reviewed sources is the gold standard.  

Thank you!!, but also the link I posted was from the Peace Region Paleontological research centre.

[Kane]

23 minutes ago, dinosaur man said:

Thank you!!, but also the link I posted was from the Peace Region Paleontological research centre.

Indeed you did! However, you'll notice where they occasionally link to the scientific paper: that is where to acquire the source to cite.  

[dinosaur man]

I have been working on a word document about everything I’ve learned on this subject, I will share what I have when I’m done it!! And Thank you all for your comments!! they have been really helpful!!

[Arion]

2 hours ago, dinosaur man said:

I have been working on a word document about everything I’ve learned on this subject, I will share what I have when I’m done it!!  And Thank you all for your comments!! they have been really helpful!!

Sounds good, looking forward to seeing it  

[dinosaur man]

I’ve been recently informed after talking to the curator Andrew Lawfield of the Peace Region Paleontological Research Centre about the Tumbler Ridge Tyrannosaur and he said this “I've been informed that there may be a research publication currently in progress, although I'm uncertain what stage this has reached.“ this was about a possible paper on the Tumbler Ridge Tyrannosaur which could help my research, and other research on Tyrannosaurs, and Dinosaurs of the area.

[dinosaur man]

I have just found this out "

Meters found above sea level, a few of the skeletons from Dinosaur Provincial Park:  

681 meters Eastern part of the Park TMP 1992.036.1220 

662 meters Western part of the Park TMP 1985.062.0001 

695 meters stern part of the Park FMNH PR308 

674 meters Eastern part of the park ?  

? AMNH 5438 

All the skeletons found so far in the Dinosaur Park Formation are in the 660 to 700 meters above sea level range."