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Tooth And Bone Pathologies


Harry Pristis

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15 hours ago, Harry Pristis said:

epicyonhaydenisenile.jpg.78a656258019046e477e1106f75f448b.jpg

 

Here is the jaw of Epicyon haydeni with extremely worn teeth -- I think that constitutes a pathology, doesn't it? 

 

This is a borophagine (literally, "gluttonous eater") dog, with teeth specialized for crushing bone -- eating everything. The Borophaginae were a large subfamily with many successful species. Epicyon haydeni is the largest representative known from Florida. The last representative of the Borophaginae, Osteoborus sp., became extinct in the Pliocene.

 

One prominent feature of these dogs was the large and crowded lower premolar four (p4) and molar one (m1 - the carnassial). Premolar three was reduced in size. This arrangement of teeth turned the p4-m1 conjunction into a crushing platform for reducing meat and bone to an appropriate size.
 
Notice in this example that, while all the teeth are heavily worn, the crucial p4-m1 crushing platform is destroyed. It wasn't broken as a fossil. The carnasial was worn down in life to its two roots -- you can make out the wear facets on the stubs.
 
We can't say how this dog died. It was not an abscess on this jaw that killed it. I like to think it was simply old age -- that the king (or queen) just wore out . . . as did his teeth.

 

Hi Harry,

 

From what I've read a pathology is damage or modification resulting from disease or injury (Thomas et al., 2008).  Specimens showing natural, in-life wear wouldn't be examples of pathology.  I think any extreme example of natural wear like the Epicyon jaw is close enough for this thread. 

 

I don't see a lot of senile specimens but some Allodesmus teeth I have show heavy wear.  I've seen a few heavily worn horse teeth.  I'll see what I can get photos of and post them here.

 

https://www.researchgate.net/profile/Xiaoming_Wang6/publication/252086599_Geology_and_Vertebrate_Paleontology_of_Western_and_Southern_North_America/links/5625900908ae4d9e5c4bb863/Geology-and-Vertebrate-Paleontology-of-Western-and-Southern-North-America.pdf#page=159

 

Jess

 

 

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17 hours ago, siteseer said:

 

Hi Harry,

 

From what I've read a pathology is damage or modification resulting from disease or injury (Thomas et al., 2008).  Specimens showing natural, in-life wear wouldn't be examples of pathology.  I think any extreme example of natural wear like the Epicyon jaw is close enough for this thread.

 

Jess

 

 

 

Hi Jess,

 

I’ve seen a couple Squalicorax teeth from New Jersey that have a wrinkly lingual surface and one which has strange bumps (they look like Braille code) on the labial face. It seems like that type of deformation would come from one tooth rubbing another tooth still in the process of development. This deformity isn’t because of disease or injury (unless an injury somehow caused tooth files to be jammed very close to each other) so would this still be considered a pathology?

 

Joseph

“You must take your opponent into a deep dark forest where 2+2=5, and the path leading out is only wide enough for one.” ― Mikhail Tal

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6 hours ago, The Jersey Devil said:

 

Hi Jess,

 

I’ve seen a couple Squalicorax teeth from New Jersey that have a wrinkly lingual surface and one which has strange bumps (they look like Braille code) on the labial face. It seems like that type of deformation would come from one tooth rubbing another tooth still in the process of development. This deformity isn’t because of disease or injury (unless an injury somehow caused tooth files to be jammed very close to each other) so would this still be considered a pathology?

 

Joseph

 

Hi Joseph,

 

From what I've seen with modern sharks, when one tooth is pressed into another tooth, it's because of an injury.  Hammerhead sharks have been caught with stingray spines sticking into their mouths, sometimes disrupting at least one tooth file.  Squalicorax lived at a time before rays had caudal spines but various species could have had similar injuries attacking hybodonts which bore a spine in front of each dorsal fin or perhaps from biting into a bone at an awkward angle.  Of course, when looking at an isolated deformed tooth, it's impossible to say for sure what caused it.  It is possible that one file didn't develop normally due to some birth defect causing one tooth to lean into another.  We can only look at the deformed teeth of modern sharks of which the cause of the deformity is known and see how that can help interpret fossil specimens. 

 

It all depends on how we want to define a pathology.  The Howell et al., 2008 article was actually talking about bone pathologies but I think the definition works for teeth too.  Most comments on deformed teeth tend to be spoken without documentation but there are at least a couple of papers on the subject.

 

Jess

 

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  • 2 years later...

I can't believe it's been over two years since this excellent thread from the old days was bumped.

 

Here's a juvenile great white shark tooth from the Early Pliocene of Chile that appears to have been slightly crowded by another tooth or otherwise impacted as it was forming.  It measures 5/8 of an inch or 15mm.  It appears to be the third upper anterior but the shape is irregular enough to call it a mild pathology.

 

The serrations are also irregular.  Some would say that's evidence of a transitional tooth but baby/juvenile great whites can be irregularly-serrated or unserrated even today. 

 

 

 

 

 gw_patho1b.thumb.jpg.579f8c321a0fab661b306f49b5197697.jpg

gw_patho1a.jpg

Edited by siteseer
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  • 10 months later...

Let's revive this thread, because, surely, we haven't seen all the pathologies available.

Here's a Bison tooth with unusual wear.  If you discount wear as a pathology, there is here at least an implicit pathology in the host jaws that produced this extreme, off-center wear.

Show us YOUR pathological specimens.

 

1851680600_bisonP3comp.JPG.92b6275ed41d2770ead4034c68dd6a62.JPG749517996_bisonP3patho.JPG.78f03c0045e027018f5b17fa95ef247b.JPG

 

http://pristis.wix.com/the-demijohn-page

 

What seest thou else

In the dark backward and abysm of time?

---Shakespeare, The Tempest

 

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