Some teeth in jaw

[Brandy Cole]

Fighting a sinus infection but made it out to the river today for a brief look.  Southeast Texas gravel bar.  Mostly Pleistocene, but older fossils are theoretically possible from exposures up river.

 

Didn't find much since the river is up, but my most interesting find was this jaw fragment with some teeth intact.

 

Since the biting surfaces are so worn, I'm having trouble with an ID.  Is it possible to ID this based on tooth size/shape/location in the jaw?  Or to at least narrow it down more so I can refine what type of teeth I should be comparing it to?

 

Thanks.

--Brandy

[Shellseeker]

1 hour ago, Brandy Cole said:

Since the biting surfaces are so worn, I'm having trouble with an ID.  Is it possible to ID this based on tooth size/shape/location in the jaw?  Or to at least narrow it down more so I can refine what type of teeth I should be comparing it to?

Brandy,

The biting surfaces are not worn down .  The teeth are broken off at the root level.

 

I found a similar length of jaw ( a little over 3 inches) 5 years ago. Like yours, the teeth are broken, but there are only so many animals in the fossil record at this size and you can make a good guess at the number and type of teeth.

 

@Harry Pristis recognized the pattern of broken teeth to predator, and we eventually narrowed it down to Dire Wolf right side mandible.  I would say that yours is likely a left side mandible and likely not a predator... Note how predators have a nice single file of round teeth roots with a centering hole!!

 

 

Your tooth: ONE Possibility.  The teeth on the right may be premolars and the tooth on the left a molar. The Molar might have 4 roots or 2 roots connected in the back and 2 roots connected in the front. Note the 2 centering holes in each root.  Tapir is one of the animals that have teeth and roots like this....

 

Here is an interesting thread...

http://www.thefossilforum.com/index.php?/topic/108423-fossillarrys-mammals/&tab=comments

and another

http://www.thefossilforum.com/index.php?/gallery/image/1189-tapirus-veroensis-juvenile/

 

 

[Shellseeker]

Here is another recent thread where I was hoping for Sloth, but it turned out to be tapir. Looking again at the broken tapir tooth , makes me less likely to think that your jaw is Tapir.  The tooth is not shaped the same way.  We will see what others think... Jack

 

[Kiros]

It looks like a giant sloth jaw

Possibly paramylodon? 

 

[Lorne Ledger]

Paramylodon would be a good guess if not for the errant root fragment in the lower portion,  My guess is Llama left mandible with both teeth broken off below the gumline.  The size is right for Hemiauchenia I think.  Two teeth in the jaw section and what we are seeing are just the roots.

 

 

[Shellseeker]

31 minutes ago, Lorne Ledger said:

The size is right for Hemiauchenia

I am really stumped on this one... The alveoli  of the fossil camels go up and down the mandible not left and right.

 

The alveoli  of the fossil camels go up and down the mandible not left and right.

 

Could it be peccary ? that would be like tapir, but not tapir and I have little experience with peccary teeth.

 

[Brandy Cole]

@Lorne Ledger @Shellseeker @Kiros

 

Thank you all for taking a look!  I've learned a lot from the comments.  

I was looking through Gilbert's osteology book and had also wondered about peccary, since I also thought it was weird that the teeth seemed 'wider' than they are 'long', if that makes sense.  I'm used to seeing teeth be longer from proximal to distal end, not from lingual to buccal side like these appear to be.

 

But I also didn't consider that the jaw could be broken further down than I thought and they could be just roots, like Lorne suggested.

 

I did notice the parts Lorne described as errant root fragment.  I actually saw more than one, and at least one hole that looked like it had one that fell out.

 

I tried to take some brighter pictures of the surface this morning.

 

--Brandy

[Kiros]

2 hours ago, Lorne Ledger said:

Paramylodon would be a good guess if not for the errant root fragment in the lower portion,  My guess is Llama left mandible with both teeth broken off below the gumline.  The size is right for Hemiauchenia I think.  Two teeth in the jaw section and what we are seeing are just the roots.

 

 

Ooh I see what you mean. I didn't notice that little root at all. Still the camel mandible or peccary doesn't convince me. Those roots sections have such a strange and peculiar shape

[Lorne Ledger]

I don't think those are full root sections, they are ground down.  It's hard to tell where the actual gumline would be.  I still stand by my ID of llama, but I do have another hypothesis to add in here -----  this could be part of an upper maxillae heavily worn.  The uppers on on a camel have multiple roots and depending on just where it was worn down in the jaw could account for the shape seen in this piece of the orientation of these root fragments.  I have some teeth I can post later that could account for the errant root alveoli seen.

[Brandy Cole]

@Lorne Ledger

Thanks Lorne!

 

Here are some side views in case that's helpful.

[hemipristis]

[Jared C]

My opinion certainly isn't as informed as the folks who have commented on this already, so I think I'd be better off asking questions instead... did Texas even have Llamas during the Pleistocene? I've never heard of Llamas being mentioned for this time. We certainly had other camels though....

[Brandy Cole]

22 minutes ago, Jared C said:

My opinion certainly isn't as informed as the folks who have commented on this already, so I think I'd be better off asking questions instead... did Texas even have Llamas during the Pleistocene? I've never heard of Llamas being mentioned for this time. We certainly had other camels though....

Yes, as I understand it, paleolama are possible in pleistocene formations here, and I've found a couple of astragalus that appear to match for it.

@Lorne Ledger has found much more than I have and knows more about it, but here's an article with sample distribution in several states.

https://www.researchgate.net/figure/Geographic-distribution-of-Palaeolama-mirifica-in-North-America-during-the-Pleistocene_fig3_273458749

[Brandy Cole]

@Jared C

I forgot about hemiauchenia too.

 

https://en.m.wikipedia.org/wiki/Hemiauchenia

[darrow]

I'm thinking Suggestive (but NOT diagnostic) of Tapir for a couple reasons.  One because of the root structure as Jack suggested, but also because of the cross-section of the bone.  What remains of the bone suggests a very robust body of the mandible.  The bone appears to be particularly wide with respect to the teeth with a deep rounded profile... unlike paramylodon or hemiauchenia.

 

For comparison...

Tapir Jaw Fossil - Fossils & Artifacts for Sale | Paleo Enterprises

 

[MarcoSr]

I found this discussion extremely interesting.  I’ve found hundreds of small terrestrial mammal jaws and partial jaws, thousands of complete individual small mammal teeth, and thousands of rootless crowns of small mammal teeth in anthill matrix from my sons’ Eocene/Oligocene ranch in Nebraska over the last five years.  All the papers describing the different genera/species of these White River terrestrial small mammals, that I’ve seen, discuss the crowns of the teeth and really don’t address tooth roots at all.  It could be because the roots of the teeth are still in the jaws.   However, there are also lots of individual loose teeth of these genera/species that could be also used to describe the roots.  So I was under the impression that at least with small terrestrial mammals the tooth roots aren’t diagnostic either because there is too much variability within a genus/species itself or too much similarity between different genera/species.  However, this discussion makes it sound like in large terrestrial mammals tooth roots alone can be diagnostics and that just the remaining tooth root pattern in a large terrestrial mammal jaw can ID the jaw.  My main question is “Are tooth roots diagnostic in large terrestrial mammals?”.  I accept that if a certain large terrestrial mammal genus/species had very unique tooth roots that the roots could be diagnostic.  However, in general, are tooth roots of large terrestrial mammal teeth used to ID individual teeth to a genus/ species?  Are tooth root patterns in a large terrestrial mammal jaw a reliable way to ID a jaw to a genus/species?

 

Marco Sr.

[darrow]

Very good points Marco Sr and I would answer “No” all your questions.

 

“Diagnostic" is a very high threshold implying published peer reviewed study.  While tooth roots in general may be suggestive of a particular genus/species, I don’t think they could be considered even “reliable” for the reasons you point out; interspecies variability and intraspecies similarity. 

 

Humans are an example of such variability…

Five-rooted permanent maxillary second molar: CBCT findings of an extremely rare anatomical variant (nih.gov)

 

I don’t think there’s been a definitive identification given but I agree the discussion does make it “sound like” tooth roots alone might be diagnostic.  I’ve clarified my previous post to reflect your point.

[Shellseeker]

9 hours ago, MarcoSr said:

I found this discussion extremely interesting.  I’ve found hundreds of small terrestrial mammal jaws and partial jaws, thousands of complete individual small mammal teeth, and thousands of rootless crowns of small mammal teeth in anthill matrix from my sons’ Eocene/Oligocene ranch in Nebraska over the last five years.

Quote

Ferrari: I observe that you are in one respect a very fortunate man

 

9 hours ago, MarcoSr said:

However, in general, are tooth roots of large terrestrial mammal teeth used to ID individual teeth to a genus/ species?

Beaver, Armadillo, Glyptodont, Sloth have relative unique and have some unique shaped teeth, as do dolphin..  If Harry or I could figure out a Jaw segment without any teeth, how tough can it be for a University researcher who studies those large mammals. It would be good for TFF members to put together a list of what larger mammals can and can not be identified by a 3.5 inch section of a jaw without teeth. 

 

 

 

 

[Lorne Ledger]

Hey @Brandy Cole  That side view was extremely helpful.  

 

Okay, I have spent a bunch of time going through my fossil teeth and jaws looking for a root structure to explain what we are seeing.  I may have found an explanation but will open it up to discussion.  I have had to abandon my llama hypothesis after seeing the the side view.  What you have there is indeed a mandible section.  I think it represents the roots of the P4 and M1 of a big cat.  Here is a pic of my Jaguar Mandible found down there on the river that is sadly also missing teeth broken off at the gumline.

 

[Lorne Ledger]

Here are some more pics for reference

 

 

[Brandy Cole]

@Lorne Ledger. That's an awesome find!

 

I hate to get my hopes up, but it would be awesome to find some predator material since you know it's been hard to come by for me so far. (But I'm drowning in turtle shell! Haha).

 

I was going to add some extra pics then realized if already posted them above. :-)

 

 

 

Edited November 6, 2021 by Brandy Cole
For clarity

[JohnJ]

On 10/23/2021 at 3:43 PM, darrow said:

I'm thinking Suggestive (but NOT diagnostic) of Tapir for a couple reasons.  One because of the root structure as Jack suggested, but also because of the cross-section of the bone.  What remains of the bone suggests a very robust body of the mandible.  The bone appears to be particularly wide with respect to the teeth with a deep rounded profile... unlike paramylodon or hemiauchenia.

 

@darrow may be onto something.  Compare to these examples Nate has online.  @PrehistoricFlorida

 

 

 

 

[Brandy Cole]

@JohnJ

Thanks for the pictures.

 

The width to length ratio of the teeth within the jaw does seem very similar to mine.

 

Also in that first picture I can see the little pegs at the edges between larger root spaces that I've noted in mine.

Edited November 6, 2021 by Brandy Cole
For clarity

[darrow]

 

Edited November 7, 2021 by darrow

[Brandy Cole]

Thanks @darrow!