Acheroraptor? Something else?

[FB003]

Hi all,

 

Trying to place an ID on it.  Seller had it listed as "dromaeosaur". I wanted the near perfect troodon tooth that came with it so didn't matter what this was. Looks like a tiny little acheroraptor to me but I could be wrong.  Still learning. Tough to get closer on the serrations even with a macro lens but if needed just let me know. Thoughts?

 

Thanks,

Frank

 

From Hell Creek - Carter County, MT

Measurements below in mm.

 

[Troodon]

Frank, can you take a straight in photo of your first image.  Need to get a better view of the crown and see what ridges are present.

[FB003]

50 minutes ago, Troodon said:

Frank, can you take a straight in photo of your first image.  Need to get a better view of the crown and see what ridges are present.

You betcha. Took a few different straight in shots.  Honestly couldn't tell if they were ridges or cracks from aging.

[Troodon]

Thank you

Like you've seen on some other of my posts we do not have any complete dentitions of the dromaeosaurids in the HC/L formations so all I have to go on is what has been published.   The lack of vertical ridges is one of the key characteristics describing an Acheroraptor and coupled with a low density difference between carinae points to it not being one..   Its not Dakotaraptor the morphology is different.   There is most likely a third Dromaeosaurid in these deposits but we have no clear definition of what the dentition looks like or even if it exist.   Might be that but for the time being I'm leaning to this being a very posterior Nanotyrannus tooth because of the denticle shape and Density.  

[FB003]

4 minutes ago, Troodon said:

Thank you

Like you've seen on some other of my posts we do not have any complete dentitions of the dromaeosaurids in the HC/L formations so all I have to go on is what has been published.   The lack of vertical ridges is one of the key characteristics describing an Acheroraptor and coupled with a low density difference between carinae points to it not being one..   Its not Dakotaraptor the morphology is different.   There is most likely a third Dromaeosaurid in these deposits but we have no clear definition of what the dentition looks like or even if it exist.   Might be that but for the time being I'm leaning to this being a very posterior Nanotyrannus tooth because of the denticle shape and Density.  

Thanks Frank.  I actually started having that inkling myself as I was going through your post on dakotaraptor vs nano teeth and trying to research it on my own.  I had ruled out dakotaraptor but started seeing some similarities to nano. I'll label it as that with a note to revisit in 5-10 years lol.  Ordered a USB microscope to make it easier to get closer and take pictures too.  This one was not fun with the macro lens on phone.

[Troodon]

Hopefully someday we will understand what these Dromaeosaurid dentition's look like and get one published on Nanotyrannus.   The HC is not quick to give up its secrets.

[FB003]

I'm sure there is plenty more to discover thats for sure.

[Dino Dad 81]

Sorry to piggyback here, but I have what looks like the adjacent tooth from the same individual 

Something my assessment showed which I think is present on @FB003 tooth also, but was missed, is a DSDI wayyyy over 1.

• Hell Creek, Garfield Co, Montana
• CH: 6.5mm
• CL: 4.0mm
• Mesial serration density: about 14/mm??
• Distal serration density: 6-7 per mm

 

 

 

 

 

 

 

 

 

 

 

[Dino Dad 81]

@Troodon, I should have tagged you on this

[Troodon]

I'm going to go on strike trying to ID teeth smaller that 10mm .  Its extremely difficult especially when we have no dentition's to compare against  no information on micro teeth.

 

This tooth might be a Richardoestesia gilmorei

 

 

I spoke to Pete Larsen saw him in June and he was pretty sure we have 3 Dromaeosaurid in the HC. Until something is found in the jaw pretty hard to say what they look like.