"Ceratosaurus" Morrison Formation Theropod tooth

[Neovenator]

Hi all!

 

I've had this tooth in my collection for a while now and I want to give a more narrow ID. It was originally sold to me as belonging to Ceratosaurus sp. and even then I knew how bold a statement that was and have had my doubts about it. My knowledge on Morrison Theropod teeth is very limited so any of your help is appreciated.

[Troodon]

Couple of questions

 

Do you have a locality where this was found?

 

What can you tell me about the mesial (outside) carina.  Hard to tell in the photo...is is worn? Can you see serrations, how far down does the carina extend from the tip ...does it go to the base?

 

Serration count of at least distal carina mid line 4 or 5 mm wide

 

Is there are partial root or is it all crown

[Neovenator]

Seems to be a partial root that's been smoothed during prep. Sending a new picture where the denticles stop marked in red. Around 20 denticles in a 5mm space on the distal carina. Mesial carina does seem to have a worn. Picture 4 shows this. 

 

I'm afraid all I know is its a Morrison Formation tooth. Can't provide more precise provenance than that I'm afraid. 

Edited May 4, 2022 by Neovenator

[Troodon]

Thanks

Well without a provenance how do you know it's from the Morrison Fm?

Pic 4 is difficult to see or determine whats going on why I asked my questions

 

 

[Neovenator]

I originally purchased it from a seller I believe has a reliable history with Morrison fossils. I bought an Allosaurus tooth from the same and I'm quite confident that tooth is consistent with the data I compared it to published by Hendrickx. Unfortunately the exact locality in which this fossil originated is lost as a result of a faded label, which is my mistake, I'm certainly more vigilant about what I use to store this information now. 

 

As for the matter of the mesial carina, it seems the enamel is still intact along the edge of the tooth which leads me to believe there aren't serrations there at all. My knowledge is patchy here so the reasoning or realism behind that isn't known to me. 

[Troodon]

Provenance, not tell you anything your not aware of but good for those who read this, is the most important bit of info needed to identify teeth or verify what you have.

 

Well if the carina does not extend to the base and appears to be restricted to the apical part of the crown my best call is that it's a Meglosauroidae, definitely not Ceratosaurus.   Without knowing what the serration density is of that mesial edge I cannot definitively say much more.

The ratios and density fit that group.

 

BTW,  Nice tooth

[Neovenator]

Thank you Troodon , I did think it looked somewhat megalosaurian but never relying on a glance. I'll dig into it again tomorrow but I'll likely mark it as Megalosauridae indet. Very pretty tooth. 

[Troodon]

I described it as a Meglosauroidae not Meglosauridae.  It could be a Marshosaurus for all we know

[Neovenator]

Ah I meant Megalosauroidea apologies, Marshosaurus was my first candidate but without seeing where the mesial carina starts and ends it gets me nowhere fast.