Theropod Tooth

[Dino Dad 81]

I think this one is a little trickier than normal. Would love to hear your thoughts!

• The hell creek formation, Powder River County, Montana
• CH: 12.5mm (small adjustment for tip wear)
• CBL: 6.8mm
• CBW: 3.6mm
• Mesial serration density: 25/5mm
• Distal serration density: 20/5mm
• Complication: The mesial carina is straight as an arrow, but highly offset. Appears to maintain furthest distance from distal carina. Anterior tooth I suspect.
• Complication: There's a significant amount of root and uneven cracking to grapple with in base cross-section

 

 

 

 

 

 

 

 

 

 

 

 

 

 

[Dino Dad 81]

One can zoom in a lot on these pic. But would it be more helpful if I post more zoomed versions?

[Troodon]

Can you take a density reading towards the tip and base of the posterior edge.  I'm I correct in seeing blood grooves on the edge.  Cool tooth whatever it is.  The CH from what point on the base?  Ridges just on labial side?

[Dino Dad 81]

Thanks for the scrutiny, @Troodon

 

There are blood grooves, you'll see them in the middle and base denticle shots below.

 

Here's what I used for CH--I don't think I could have justified smaller...:

 

To my surprise, distal denticle density is consistent throughout--it's only the height of the denticles that varies so much (2 ticks = 1mm):

 

 

 

 

Here's my attempt at assessing whether anything here could be considered a ridge:

 

 

[Troodon]

Thanks for the additional info.,

Interesting.  Your first photo gave me the appearance of ridges so will scratch that characteristic, base on the video.

The closeup images are good.  D. Evans makes a comment in the Acheroraptor paper that the largest denticles are midway in the carina and become progressively smaller apically and basally, typical of Dromaeosaurids.  Appears they are similar in your example.   Has the appearance of an Tyrannosaurid (displaced carina, lingual twist, shape of denticles, cross-section of basel but cannot explain the DSDI.) 

Probably a Tyrannosaurid but just because of size and density would call it indet.

 

[Dino Dad 81]

Interesting @Troodon, thank you!

What families tend to have blood grooves? That's a characteristics that's been totally off my radar.

 

Also, you saw 1 of 2 videos I posted in my last post. Not sure the second one will be helpful, just in case you're interested.

Edited August 26, 2022 by Dino Dad 81

[Troodon]

Forgot that characteristic in my comments.

Most families tend to have blood grooves not Spinosaurids or Abelisaurids & some others per Hendrickx (2019).   That does not mean all in that family have one or that teeth in a dentition can be mixed.  That feature is seen on T rex and have to look at my Nanotyrannus teeth.   The paper on AR and DR make no mention of them and the teeth shown don't appear to have them.  So just another unanswered mystery.

[Dino Dad 81]

@Troodon, looking back at my pics, there look like there might be discolored lighter vertical stripes. It looks like there are about four of these vertical stripes on each side. Could the tooth possibly be Acheroraptor that is worn to the point of having no noticeable fluting? There is a ton of tip wear.

[Troodon]

You cannot ID based on possibilities and what iffs especially when sides of the crown do not appear to have any wear.