Small Yixian Formation teeth - Psitaccosaurus or Jeholosaurus

[FF7_Yuffie]

Hello,

 

I bought these four rooted teeth. They are from Yixian Formation, Lujiatun Bed. The seller didn't know if Psitaccosaurus or Jeholosaurus. Looking for info online is tricky, since I couldn't find much at all to compare too..

 

I am wondering if anyone has any insight, or whether these teeth are indeed more than likely ceratopsid rather than from a small ornithopod? Also, looking at images of the Jerholosaurus skull, their teeth look to be a bit more diamond shape than these.

 

They are approximately 1.9 cm long including root. The crown on the largest is 0.6mm.

 

Pic 1 - all together

 

Pic 2 and Pic 3 - both sides of tooth 1

 

Pic 4 and 5 - both sides of tooth 2

 

pic 6 and 7 - both sides of tooth 3

 

pic 8 and pic 9 - both sides of tooth 4

 

 

Thanks for the help.

Edited June 25, 2022 by FF7_Yuffie

[FF7_Yuffie]

I found a pic of Psitaccosaurus. Doesnt look like that either becaise of the distinct ridge

 

 

[Troodon]

That ridge appears to be present on some dentary teeth not on maxillary ones.  

 

You need to be careful with unpublished images a number of similar Orthischian teeth out there and  a number of species of Psittacosaurus with variations in their teeth. 

 

Not a lot of good images of P. lujiatunensis (Yixian Fm) teeth but the holotype had one, giving us some clues on maxillary teeth including size  and vertical ridges.  There ought to pass a law that they need to be preserved  with their mouths wide open. 
 

A new species of Psittacosaurus (Dinosauria: Ceratopsia) from the Early Cretaceous Yixian Formation, Liaoning, China Chang-Fu Zhou, K. Gao, 2006

 

 

Closeup images you can compare are from other species all slightly different but similar in many characteristics

Taxonomy, Cranial Morphology, and Relationships of Parrot-Beaked Dinosaurs (Ceratopsia: Psittacosaurus) PAUL C. SERENO

 

Two others I have in my files

P. mongoliensis

P. xinjiangensis

 

I believe your teeth are two large to be Jeholosaurus

 

 

[doushantuo]

some of you may like:

Computed tomographic analysis of the dental system of three Jurassic ceratopsians and implications for the evolution of tooth replacement pattern and diet in early-diverging ceratopsians Jinfeng Hu , Catherine A Forster , Xing Xu, Qi Zhao, Yiming He , Fenglu Han

about 7 MB

 

Hu et al. eLife 2022;11:e76676. DOI: https://doi.org/10.7554/eLife.76676

 

76676.pdf

Edited June 25, 2022 by doushantuo

[FF7_Yuffie]

Thanks for the help.

 

So, tooth 1 -- to me looks like a match for the maxilliary teeth? Just a rather worn one. With the rounded top and ridges down the face of the crown. As does tooth 3, but worn at the back

 

Tooth 2 and 4 are trickier. Would the unsymmetrical shape of it likely be because of feeding ware? In this photo with the circled bit where the tooth has lost some of its rounded shape because of feeding? Or is it likely a tooth from a different part of the mouth, not covered by the papers?