Unusual Hell Creek Formation fossilized tooth record

[Joseph Fossil]

I've recently found a, how do I say...quite unusual Theropod dinosaur tooth from the Late Cretaceous Hell Creek Formation (67-66.0 Million Years ago). The paper, titled The occurrences of vertebrate fossils in the Deadhorse Coulee Member of the Milk River Formation and their implications for provincialism and evolution in the Santonian (Late Cretaceous) of North America by Derek Williams Larson, is a record of theropod teeth from various Late Cretaceous formations in Western North America, and buried on page 244 of the report an apparent megalosauridae tooth (UCMP120305) from the Hell Creek Formation (67-66.0 Million Years ago).

 

https://era.library.ualberta.ca/items/54e305be-de2a-4529-adc9-4e6b038ae699/view/28ba15f8-8131-44be-b48f-e4e9648db26e/Larson_Derek_Fall_2010.pdf

 

 

This for me is pretty unusual as Megalosauridae (as far as we know) lived only between the Middle-Late Jurassic (170-145 Million Years ago), millions of years before the Maastrichtian Cretaceous. I know in the past many theropod dinosaurs were described as species of "Megalosaurus", but that was more around the 1800-early 1900s and the citation for the tooth lists its apparent phylogenetic description as recently as 2008.

 

There was also another less confusing but fascinating description of a Dromaeosauridae tooth (UALVP48462) from the Milk River Formation, which apparently has a tooth crown height of 17.3mm.

 

 

But besides the pretty fascinating Milk River Dromeosauridae tooth, I'm puzzled about the UCMP120305 specimen! I really skeptical this tooth specimen belongs to megalosauridae. But if it's not, then where could the classification of the specimen have come from?

 

 

What do you guys think?

[Kane]

I think reaching out to the author of the thesis might prove fruitful.

[jpc]

I agree

[Troodon]

I would not read to much into that Meglosauridae posting and view it as an outlier in that appendix.  I looked at that chapter in Sankey's book and nothing was mentioned.   Look thats a 10 year old paper, the data in appendix is even older, and new discoveries have changed what has been described and known from the Hell Creek and DPF so it's an out of date thesis.

 

I would agree with the others reach out to the author or more so the source publication authors he obtained it from, if you want to pursue it.

[Troodon]

Forgot the Dromaeosauridae.

You should really go to the source document on these and ask Derek why that was identified as such, looks more tyrannosaurid to me.

 

 

Larson, D.W. 2008. Diversity and variation of theropod dinosaur teeth from the  
uppermost Santonian Milk River Formation (Upper Cretaceous), Alberta:  
a quantitative method supporting identification of the oldest dinosaur tooth  
assemblage in Canada. Canadian Journal of Earth Sciences 45: 1455–
1468