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Cowboy Paleontologist

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This is my first post, so please bear with me.  I found this tooth this summer in the Rendonda formation in Quay county New Mexico.  This should date it to the late Triassic, 202-204 mya.  The area where it was found contains almost exclusively Phytosaur fossils, but I am 99% certain that this one is not.  It measures about 2.5 cm in length and has one edge with fine serrations.  Based on the general shape and serrations, I am guessing some sort of theropod, however I do not know enough about other crocodilian species such as Postosuchus to rule something like that out.  Any help would be appreciated, and if you need more pictures/information, feel free to let me know!

 

 

 

Tooth ID serations from top.jpg

Tooth ID serations from side.jpg

Tooth ID.jpg

Tooth ID 1.jpg

Tooth ID 2.jpg

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Tooth ID (1).jpg   Tooth ID serations from side.jpg

 

Tooth ID serations from top.jpg  Tooth ID.jpg

    Tim    VETERAN SHALE SPLITTER

   MOTM.png.61350469b02f439fd4d5d77c2c69da85.png      PaleoPartner.png.30c01982e09b0cc0b7d9d6a7a21f56c6.png.a600039856933851eeea617ca3f2d15f.png     Postmaster1.jpg.900efa599049929531fa81981f028e24.jpg    VFOTM.png.f1b09c78bf88298b009b0da14ef44cf0.png  VFOTM APRIL - 2015  

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I personally click the “click to choose files” link, go to my Photo Library or camera roll and select the one I want. Then click “done” it will automatically insert them if they’re under 3.95 MB.

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Identification of Triassic teeth is very problematic since so little is known and very little published.   A number of described species are only known from the holotype based on a single incomplete specimen.   What you have may be a Theropod tooth but like you point out there are other non dinosasurian candidates that have serrated teeth.  

Not sure I have any answers but might get you closer.  It's all about the serrations.  I need a serration count, midline 2 mm wide of the distal edge and do they extend to the cervix.   Your photos are not sharp enough to see.   Does the mesial carina have any serrations or is it a smooth edge, if smooth how far does it extend down?   I would also like to see a straight in photo of the base and one of the tooth not at obtuse angles.  Are you sure you are in the Rendonda formation and not the Bull Canyon Formation?

 

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There are about 6 serrations/2mm by the tip, and they get finer to about 9 serrations/2mm at the base.  It seems that about 8/2mm is a good estimate for the majority of the tooth though.  They do continue all the way down the length of the tooth.  I don't know how well you can see in the picture, but it would seem that the carina does have some very fine serrations, about half as large as those on the distal edge, but I could not tell that they continued beyond about 4-5 mm from the point.

Also, I am certain that it was the Redonda formation.  More specifically, from what would have been a gravel river bed at the time where similarly sized rocks, teeth, and bits of bone collected.

Base.jpg

Carina Serrations.jpg

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~8 serrations/2mm.  There is a little variation depending on just where I measure, but 8 seems to be a pretty good average for midline.

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Thanks

Well here is what I can say I do not believe it's Postosuchus because they have strong serrations on both edges around 2.4/mm and it's a compressed tooth with a bi-convex base not round on maxillary and dentary positions.  However I cannot speak to other crocdylomorphs but typically the teeth would be similar.

 

On the dinosaur side we have several canidates

Coelophysis is the best understood.  It's teeth have extremely fine serrations with 8 to 9 per mm on the entire distal edge.  Anterior serrations vary from the entire edge to just the tip area.  Serration density very different than your specimen.

 

Chindesaurus is known from a couple of bones and one incomplete tooth. It's serration count is 5 per mm on both edges.   Again a bit different than your specimen , not a good specimen to compare against and I think a Norian age Dino.

 

A final candidate is Daemonosaurus and it might be the best fit but there is limited information published on the teeth.  We know, both the premaxillary and anterior dentary teeth are rounded in transverse section with compressed crowns with finely serrated mesial and distal carinae.

 

Hans-Dieter Sues; Sterling J. Nesbitt; David S. Berman & Amy C. Henrici (2011). "A late-surviving basal theropod dinosaur from the latest Triassic of North America". Proceedings of the Royal Society B. 278 (1723): 3459–3464. doi:10.1098/rspb.2011.0410. PMC 3177637Freely accessible. PMID 21490016

 

The very late Triassic timeframe works for Daemonosaurus 

Screenshot_2017-12-05-09-34-12.thumb.jpg.e72bdb112f9298e679a2d37294f0ca63.jpgScreenshot_2017-12-05-09-34-30.jpg.2460fa159ed49515630a541ae9d19f9b.jpg

 

So in the end we really do not have comparative material to make a definitive call just some possibilities.  I do however think it's dinosaurian.

 

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"I am glad I shall never be young without wild country to be young in. Of what avail are forty freedoms without a blank spot on the map?"  ~Aldo Leopold (1887-1948) 

 

New Mexico Museum of Natural History Bulletins    

 

point.thumb.jpg.e8c20b9cd1882c9813380ade830e1f32.jpg research.jpg.932a4c776c9696d3cf6133084c2d9a84.jpg  RPV.jpg.d17a6f3deca931bfdce34e2a5f29511d.jpg  SJB.jpg.f032e0b315b0e335acf103408a762803.jpg  butterfly.jpg.71c7cc456dfbbae76f15995f00b221ff.jpg  Htoad.jpg.3d40423ae4f226cfcc7e0aba3b331565.jpg  library.jpg.56c23fbd183a19af79384c4b8c431757.jpg  OIP.jpg.163d5efffd320f70f956e9a53f9cd7db.jpg

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Thanks Troodon, this is very informative!  How do you find these sources?  I spent a fair amount of time looking and never found anything relevant.

 

 

Pfooley, I would really like to know what Mr. Lucas thinks and appreciate you sending that to him.  I also will definitely be perusing those papers!

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8 hours ago, Cowboy Paleontologist said:

Thanks Troodon, this is very informative!  How do you find these sources?  I spent a fair amount of time looking and never found anything relevant.

 

Unfortunately there is not enough good reference sources out there to get a positive ID on your tooth. Triassic teeth are just a tough ID for us amateurs.  In reference to your question I just keep an extensive library of books and pdfs on dinosaurs.  Everything that is published I try to own or have it catalogued on my computer a lot like fruitbats library here in the forum.   For example the best book on Coelophysis I found in the museum of Northern Arizona, bulletin 57.  It's great for bones but only has a short section on teeth and one awful sketch on them but gives you an adequate understanding of them.

 

20171206_022409.thumb.jpg.7d2d19fa73284b06b4f4dc6bf55bfc4d.jpg

 

Most Triassic pdfs are useless on teeth, like your search has found, but part of the problem is what is a valid dinosaur since taxonomic placement continues to change or is  just not fully understood.  So here is another publication that looks at the purported  dinosaurs and re-evaluates them if they are a valid taxon. 

The study concluded that dinosaurs in this strata were rarer and less diverse than previously thought which I found very interesting.

 

Dino Triassic3.pdf

 

Postosuchus info. here is an excellent source with reasonable info on teeth:

 

https://www.researchgate.net/publication/240256263_Postosuchus_a_New_Thecodontian_Reptile_from_the_Triassic_of_Texas_and_the_Origin_of_Tyrannosaurs

 

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May I enquire as to why you think it isn't phytosaur? It reminds me of an anterior tooth of Redondosaurus, but I may be wrong-I have no knowledge of the area or of the creatures that can be found there.

"Let us therefore follow after the things which make for peace, and things wherewith one may edify another."
-Romans 14:19

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39 minutes ago, Jesuslover340 said:

May I enquire as to why you think it isn't phytosaur? It reminds me of an anterior tooth of Redondosaurus, but I may be wrong-I have no knowledge of the area or of the creatures that can be found there.

It could be not that familiar with phytosaurs do you have something that documents the teeth of this species

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10 hours ago, Cowboy Paleontologist said:

Pfooley, I would really like to know what Mr. Lucas thinks...

He thought it was definitely an Archosaur tooth, but saw nothing definitively dinosaur about it. 

 

 

"I am glad I shall never be young without wild country to be young in. Of what avail are forty freedoms without a blank spot on the map?"  ~Aldo Leopold (1887-1948) 

 

New Mexico Museum of Natural History Bulletins    

 

point.thumb.jpg.e8c20b9cd1882c9813380ade830e1f32.jpg research.jpg.932a4c776c9696d3cf6133084c2d9a84.jpg  RPV.jpg.d17a6f3deca931bfdce34e2a5f29511d.jpg  SJB.jpg.f032e0b315b0e335acf103408a762803.jpg  butterfly.jpg.71c7cc456dfbbae76f15995f00b221ff.jpg  Htoad.jpg.3d40423ae4f226cfcc7e0aba3b331565.jpg  library.jpg.56c23fbd183a19af79384c4b8c431757.jpg  OIP.jpg.163d5efffd320f70f956e9a53f9cd7db.jpg

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9 minutes ago, Troodon said:

Anything in the paper that describes the teeth?

Page 37...

"I am glad I shall never be young without wild country to be young in. Of what avail are forty freedoms without a blank spot on the map?"  ~Aldo Leopold (1887-1948) 

 

New Mexico Museum of Natural History Bulletins    

 

point.thumb.jpg.e8c20b9cd1882c9813380ade830e1f32.jpg research.jpg.932a4c776c9696d3cf6133084c2d9a84.jpg  RPV.jpg.d17a6f3deca931bfdce34e2a5f29511d.jpg  SJB.jpg.f032e0b315b0e335acf103408a762803.jpg  butterfly.jpg.71c7cc456dfbbae76f15995f00b221ff.jpg  Htoad.jpg.3d40423ae4f226cfcc7e0aba3b331565.jpg  library.jpg.56c23fbd183a19af79384c4b8c431757.jpg  OIP.jpg.163d5efffd320f70f956e9a53f9cd7db.jpg

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23 minutes ago, Troodon said:

It could be not that familiar with phytosaurs do you have something that documents that species

Nothing that describes the teeth. Just a free book on Google Books describing the holotype. The holotype was found in the same county, though.

 

https://books.google.com.au/books?hl=en&lr=&id=qbP9CQAAQBAJ&oi=fnd&pg=PA193&dq=redondasaurus+holotyoe&ots=WxFsaVKEDj&sig=Z1B7LzIAPjmykdYQbNrc0YXn4wE#v=onepage&q=redondasaurus holotyoe&f=false

"Let us therefore follow after the things which make for peace, and things wherewith one may edify another."
-Romans 14:19

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11 minutes ago, PFOOLEY said:

Page 37...

In reading the description of the teeth its definitely not Redondasaurus.  Those teeth are conical lacking a carinae just the opposite of the tooth in question.  Isolated triassic teeth are very hard to ID.

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Screenshot_20171206-231244.png

"Let us therefore follow after the things which make for peace, and things wherewith one may edify another."
-Romans 14:19

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38 minutes ago, Jesuslover340 said:

Screenshot_20171206-231244.png

I don't think we are dealing with the large rostral teeth in the bulb or premaxilla but the other teeth. " The posterior two teeth are more indicative of the rest of the premaxillary dentition; they are conical teeth lacking carinae."  Not much is said in the paper of the dentary or maxillary teeth but the morphology in the photographs look similiar to the posterior Premaxillary ones.

 

Let me add that the round base is more indicative of non dinosaurian archosaurs but I don't have enough knowledge of Triassic dinosaur teeth to know if any exhibited that morphology 

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