Parasaniwa Tooth

[PaleoNoel]

Happy New Year everyone. Tonight I thought I might post a fossil whose identity I wanted to confirm. I found it in Wyoming's Lance formation this summer and someone told me it might be a Pachycephalosaur premaxillary tooth because of it's carinae and ridges at the base. However after comparing my tooth to examples I could find online I felt that this ID was incorrect. Eventually I looked back over one of  @Troodon's threads and found a jaw labelled as parasaniwa and those teeth matched what I had found. 

My tooth is about 6 mm long and about 3 mm wide.

[jpc]

I was ready to say Parasaniwa,  but I am not sure if P has the carina running down the inside of the curve.  At the same time, I did not know that Pachy has the wrinkled base of the tooth....

 

[PaleoNoel]

1 hour ago, jpc said:

I was ready to say Parasaniwa,  but I am not sure if P has the carina running down the inside of the curve.  At the same time, I did not know that Pachy has the wrinkled base of the tooth....

 

I don't know if pachy does, it was probably just a misidentification. Here is a pachy premax posted by Denver Fowler on Twitter. I couldn't find a better match than Para for my tooth.

[jpc]

I just read Estes 1964's description of Parasaniwa and he does not mention carinae on the teeth, so I will say.... mystery tooth.  (I see now that your tooth has both anterior and posterior carinae.)

[PaleoNoel]

@Troodon do the teeth in your jaw section have carinae?

[PaleoNoel]

Following up, @troodon I believe you were away from the forum when I posted this. Do the teeth in your jaw have carinae?

[Troodon]

Sorry I was sick at that time, did not see it  Let me check my jaw.

[Fossildude19]

Cropped and brightened:

 

 

 

 

   

[Troodon]

Here is a closeup of some of the teeth in my jaw.  There is an unserrated carina on both edges that extends slightly below half way.   Yours seems to have dimples/serrations on the carina.  The base is very similar to yours and heavily infolded around the perimeter typical of Varanoids.  

 

Thanks to your question I researched the following and changed my opinion on my jaw.

 

Longrich et al. Mass extinction of lizards......(2012) describes a new jaw from the Lance as Cemeterius monstrosus and states that Palaeosaniwa wyomingensis and Paraderma  bogerti are also present and the former being the largest, unfortunately no photos of the teeth but describes Palaeosaniwa teeth as follows:

• Microserrations present
• Carina extends the full length of the crown on both carinae
• Tooth base heavily infolded
• Labiolingually compressed teeth

 

Cemeterius teeth are described as follows

• Labiolingually expanded
• Short massive crown
• Hooked Posteriorly 
• Tooth base heavily infolded
• No mention on extension of carinae

 

Yours looks like a Varanoid lizard tooth but not sure which one and I now believe mine is Cemeterius.   You might want to contact Nick yours is a bit different if those are real dimples versus wear.  If the latter looks like Cemeterius.

 

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Cemeterius monstrosus

 

A Varanoid jaw in my library of images

 

[jpc]

do you have a pdf of that paper, troodon?  Or did you find it online?

 

[Troodon]

12 minutes ago, jpc said:

do you have a pdf of that paper, troodon?  Or did you find it online?

 

 

Here you go.  The detail is in the SI Appendix

 

.Lizard Jaws Longrich.pdf

 

 

 

[PaleoNoel]

3 hours ago, Troodon said:

Here is a closeup of some of the teeth in my jaw.  There is an unserrated carina on both edges that extends slightly below half way.   Yours seems to have dimples/serrations on the carina.  The base is very similar to yours and heavily infolded around the perimeter typical of Varanoids.  

Thanks to your question I researched the following and changed my opinion on my jaw.

Longrich et al. Mass extinction of lizards......(2012) describes a new jaw from the Lance as Cemeterius monstrosus and states that Palaeosaniwa wyomingensis and Paraderma  bogerti are also present and the former being the largest, unfortunately no photos of the teeth but describes Palaeosaniwa teeth as follows:

• Microserrations present
• Carina extends the full length of the crown on both carinae
• Tooth base heavily infolded
• Labiolingually compressed teeth

Cemeterius teeth are described as follows

• Labiolingually expanded
• Short massive crown
• Hooked Posteriorly 
• Tooth base heavily infolded
• No mention on extension of carinae

Yours looks like a Varanoid lizard tooth but not sure which one and I now believe mine is Cemeterius.   You might want to contact Nick yours is a bit different if those are real dimples versus wear.  If the latter looks like Cemeterius.

 

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Thanks for your help! Upon close inspection, there are extremely tiny serrations along both edges of the tooth, which don't even get picked up by the digital microscope's camera, only showing up when viewed through my loupe if the angle of light is right. However, I think my tooth is nearly identical to those in your jaw section and I feel that Cemeterius is the right call.

[jpc]

11 hours ago, Troodon said:

 

Here you go.  The detail is in the SI Appendix

 

.Lizard Jaws Longrich.pdf

 

 

 

Thanks for this, troodon.  And thanks for mentioning that the good stuff is in the appendix.