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Bands in Marine Mammal teeth


Shellseeker

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I recently found a distressed canine in the Peace River. When possible I really want to identify all such fossil canines. The length is 1 and 1/8 inch. At the river I seemed to see (photo #1 & #2) "latitudinal banding" which means marine mammal.  At home, I note that the root end turns to the side of the canine (photos #3 & #4), a characteristic that I mostly associate with porpoise.  

DolphinWhaleCrop.JPG.06565d1dd881834281709b79efc27e8d.JPGIMG_1469a.thumb.JPEG.aa742b4330b88731d41953c1a64858a7.JPEGDolphinWhaleCrop4.JPG.36e65ccf06298cf15cc2ccbf6a8dc22a.JPGDolphinWhaleCrop3.JPG.05cbcb6b7cad16e11f09cd71d2a42291.JPG

 

So , what is my question:

Do all Dolphin/Porpoise teeth have such banding? The only reason I do not detect it on 95% of my Florida Dolphin/Porposie fossil teeth is that the banding is covered by cementum.

I appreciate all responses,   Jack

 

Here is a picture of Whale tooth composition. 

WhaleToothComposition.JPG.fb07fdba938ee0da83c2098bc3c300df.JPG

 

These are Peace River or Bone Valley Whale Teeth:

IMG_5441.thumb.JPG.4f2c44dd06d9d668f07059bf15e1f861.JPG

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The White Queen  ".... in her youth she could believe "six impossible things before breakfast"

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Jack, are the dolphin teeth on your side of the States usually that big?  It seems like it might be a small cetacean of sorts but way bigger than the dolphins I am accustomed to here.

You want to talk about banding,  check this one I got early Summer.

 

20191121_100152.jpg

20191121_100214.jpg

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2 hours ago, caldigger said:

Jack, are the dolphin teeth on your side of the States usually that big?  It seems like it might be a small cetacean of sorts but way bigger than the dolphins I am accustomed to here.

You want to talk about banding,  check this one I got early Summer.

 

20191121_100152.jpg

20191121_100214.jpg

 

 

Cal,

You have made someone happy today !!!:yay-smiley-1::megdance::fistbump::fistbump::fistbump:..

I am unsure which piece I should go after first.

1) I see differences & similarities in the sample of marine mammal (whale, porpoise, harbor dolphin) I find in the Peace River and I am unsure what, if anything, those differences and similarities can teach me. I have gone down this rabbit hole before and it is just an itch that I can not scratch. Accurate Identification of random dolphin /porpoise teeth is impossible.

2) Given #1,  decided to ask the forum about the banding question... Any whale fossil tooth coming from the Peace River has bands. Kentriodontid dolphin teeth (3-4 inches, thinner than whale) from the Peace River have bands. I have found many/most small dolphin teeth that do not seem to have bands (usually these are thin, have those perpendicular facing root tips, and equal or less than an inch) and harbor dolphin "spatula" teeth that also seem to lack bands.

This year I have found 2 larger marine mammal teeth, one at 1.6 inches showing no bands and this one at 1.125 inches showing bands. I have found 2-3 similar teeth for a total of 5 over the last 11 years. The following TFF link shows the 1.6 inch tooth.

http://www.thefossilforum.com/index.php?/topic/95030-larger-dolphin-tooth/

So my question on banding: Does anyone think that these is banding on the smallest dolphin teeth? ... In North Carolina, California, etc

Cal - just to affirm... It seems like it might be a small cetacean of sorts but way bigger than the dolphins I am accustomed to here. Agree , same experience in Florida

3) Now the excitement!!!!.  In December , 2015, I found a small tooth amazingly similar to your tooth ... Does it not look like dentine bands on the outside surrounding enamel.. I have never seen anything like it.  No one ever responded to my request for ID.   We have TWO, one on each coast. :raindance:

Tell me whatever you can about your tooth..  length, 1st ever ?? are you trying to ID?  Jack

5dd6f6dd8b109_December2015058.thumb.JPG.edf8c96eee40f434828b7216a4354270.JPG5dd6f6def22f6_December2015059a.thumb.jpg.81b9b8c9dcd5f7b67d079d01106cd8dd.jpg5dd6f6e01fb36_December2015060.thumb.JPG.807aa0f904f961dd565214af4c2ff0fb.JPG

 

 

The White Queen  ".... in her youth she could believe "six impossible things before breakfast"

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I don't understand the question addressed in this thread.  I thought these toothed whale (odontocetes) teeth all were constructed in the same manner.  Shed of their cementum, they all show these growth rings, though the teeth may vary in diameter, length, and curvature.  Dolphins are odontocetes, and any distinction between "dolphins" and "whales" is not very useful in this context.  Anyway, that's my understanding -- correct me if I'm wrong.

 

 

whale_tooth_small.JPG.607da444faed90d29e651e12569f5792.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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42 minutes ago, Harry Pristis said:

I don't understand the question addressed in this thread.  I thought these toothed whale (odontocetes) teeth all were constructed in the same manner.  Shed of their cementum, they all show these growth rings, though the teeth may vary in diameter, length, and curvature.  Dolphins are odontocetes, and any distinction between "dolphins" and "whales" is not very useful in this context.  Anyway, that's my understanding -- correct me if I'm wrong.

 

 

Harry,

My understanding was the same as yours. I take the knowledge and the science of tooth growth in odonticetes but over time I compare it to experience. What do I see in nature and then how do I explain what I see?

So, specifically for the Peace River (and Bone Valley mines), I have noted that for all whale and most/all Kentriodontid dolphin teeth either broken or whole, it is trivial to detect growth rings.

I have found a large number of small dolphin teeth and a much smaller number of harbor dolphin teeth in the Peace River. Broken or not , I can only recall one instance in the last 12 years finding growth rings on a small (less than 30 mm ) dolphin tooth. I was concerned that the only small tooth I had found (above) with banding, was not identifiable, and not common.

 

I recognize that the fact that I can not see growth rings does not necessarily indicate that they are not there. For whatever reason , cementum may cling to small teeth over larger ones, or growth rings are not as visible in the tannin heavy water, or, or.....

 

It seems easy to ask a TFF community that had access to thousands of small dolphin teeth asking if their experience if different and if they have a photo.  Then I would continue to collect data based on the response or lack thereof.

 

 

 

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The White Queen  ".... in her youth she could believe "six impossible things before breakfast"

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@Harry Pristis

 

Harry,  Full disclosure.

http://www.quekett.org/resources/article-archive/dolphin-teeth

The article basically talks about analyzing modern dolphin teeth with a 160x microscope for the purpose of estimating age.

 

So, the growth rings exist in the Harbor Dolphin... I am still seeking the answer to why I can not see them , or have not found one that shows the growth rings. Certainly would appreciate any TFF member photos showing the growth rings.

The White Queen  ".... in her youth she could believe "six impossible things before breakfast"

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25 minutes ago, caldigger said:

Are the Harbor Dolphins the "long grain rice" size teeth?

 

Yes,

Same sized.  A couple of TFF links of this spatula type tooth.  I have seen a statement that Harbor Dolphins are the only true dolphins. When we call dolphins are actually porpoises...

I also have found some dolphin teeth, similar to those in your display box, which are not "Harbor Dolphins"  Do the teeth in your display have "growth rings".. They look like enamel and root.

 

Finally , I am still searching for info on growth rings.  Here is a photo of a Miocene Dolphin from Japan. Whale teeth has dentine covered by cementum. This tooth has dentine covered by enamel.  Do not know if it means anything yet.

f03_97JapanporpoisetoothTxt.JPG.ebb0aa7faef931efa96b9364497dd9d2.JPG

 

The White Queen  ".... in her youth she could believe "six impossible things before breakfast"

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Yes, I belive these little guys only have roots and crown enamel.  Not like the "banana" shaped cetacean teeth that  are more like toothed whales.

I only seem to find the tiny teeth ( porpoise? ) and larger toothed whale dentures.  That striped one I posted the picture of is the only one like that I have found in my digs.

 

These are my usual fare. Either the Sperm Whale teeth that don't seem to have any enamel crowns or the ones on the left with root and hooked/curved crowns.

The Sperm Whale teeth of which I have had many in the past,  do not appear to have those sections or stripes. 

20191121_211321.jpg

 

 

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Modern dolphin teeth have hollow pulp cavities that slowly fill in with layers as they age. Eventually the pulp cavities will completely fill in. Enamel and cementum covering prevents us from seeing these layers but they can be seen if sliced open.

 

 

beluga.JPG

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9 hours ago, caldigger said:

These are my usual fare. Either the Sperm Whale teeth that don't seem to have any enamel crowns or the ones on the left with root and hooked/curved crowns.

The Sperm Whale teeth of which I have had many in the past,  do not appear to have those sections or stripes. 

 

I see growth rings in your leftmost sperm whale tooth: I have many like it from Bone Valley... Your other sperm whale teeth likely have growth rings covered by cementum.  We seem to find the same range of teeth (I do NOT have Squalodon or proSqualodon).  The small ones with enamel caps are extremely rare in my part of Florida.  Thanks...

SpermWhalebanding.JPG.c12291dcd812e9af5f42cb887eb1baa1.JPGTffBandingexampletooth.JPG.833131f53fd9e2eb953dac7f139a4154.JPG

 

 

The White Queen  ".... in her youth she could believe "six impossible things before breakfast"

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6 hours ago, Al Dente said:

Modern dolphin teeth have hollow pulp cavities that slowly fill in with layers as they age. Eventually the pulp cavities will completely fill in. Enamel and cementum covering prevents us from seeing these layers but they can be seen if sliced open.

 

 

beluga.JPG

 

Al Dente,

Thanks for the response and picture.  It may help me to better understand the science. I had , incorrectly, thought that growth bands were added to the outside of the tooth. Turns out that the picture I added from the Japan paper (above) and your picture show just the opposite. The growth rings grow into the pulp cavity. Some questions: Does this imply that the the tooth is adult full size at birth? Do cementum and Enamel both have growth rings also? When the pulp cavity is "full", does that stop the growth ring process?

Here is a rare tooth (for Florida) that I found this spring in the Peace River... It is 1.6 inches in length. I have no doubt that there are growth rings under that cementum.  Are there growth rings also in the enamel cap?

IMG_5952.thumb.jpg.69a1956f3297eb4a8d1309d64d2449c6.jpg

 

I am trying to understand why with small (< 1 inch) teeth like Harbor Dolphin or the teeth that  @caldigger has in the display case above, that I "see" no growth rings , even when they are broken !! Vast majority of dolphin or whale teeth I find are broken.

Possibly, my human eye can not detect the growth rings in very small teeth, and would require a microscope to detect. I still wait on a post with a broken small dolphin tooth showing the growth rings. 

I have always loved a mystery...things I can not explain. Sometimes that is just the way it goes

The White Queen  ".... in her youth she could believe "six impossible things before breakfast"

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2 hours ago, Shellseeker said:

Does this imply that the the tooth is adult full size at birth?

Very few mammal teeth will grow, mostly tusks.

 

2 hours ago, Shellseeker said:

Are there growth rings also in the enamel cap?

No. The enamel forms all at once.

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Comments on mammal tooth development.
Dentin and cementum are deposited within the crypt in a complicated progression: a kernel or "shard" of dentin is the first step. enamel, then orthodentine, more dentin, then cementum. The softest of these different materials, cementum, is often lost in fossil teeth, and sometimes death intervenes to interrupt late-stage tooth development.
 
The timing of cementum deposition could cause confusion. It is the enamel epithelial sheath, which encloses the enamel crown, that must be breached before cementum can be deposited. That breach takes place at the cellular level. That is a different thing from the tooth erupting from the alveolar crypt.
 
Beginning with a sieve-like penetration by mesodermal cells, part of the enamel epithelial sheath breaks down. Cementum-producing osteoblasts ("cementoblasts" of some authors) from surrounding tissue then deposit cementum on the now-available crown enamel. Dentin continues to be deposited on the interior (pulp cavity).
 
Then, osteoclasts open the bone which protects the crypt. In the case of a premolar, the osteoclasts also attack the roots of a deciduous antecessor. The tooth emerges under hydrostatic pressures. Once the tooth crown emerges from the crypt, the "cementoblasts" are no longer supported and are finished with their work on the crown.
 
The fact that there are to be found rootless, hollow enamel shells of teeth is an accident of when the animal died in this sequence of tooth development.
 
ref.  Bernhard Peyer's COMPARATIVE ODONTOLOGY as translated and edited by Rainer Zangerl with a forward by A. S. Romer. Maybe there is newer, better information published now.
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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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2 hours ago, Harry Pristis said:
Comments on mammal tooth development.
Dentin and cementum are deposited within the crypt in a complicated progression: a kernel or "shard" of dentin is the first step. enamel, then orthodentine, more dentin, then cementum. The softest of these different materials, cementum, is often lost in fossil teeth, and sometimes death intervenes to interrupt late-stage tooth development.
 
The timing of cementum deposition could cause confusion. It is the enamel epithelial sheath, which encloses the enamel crown, that must be breached before cementum can be deposited. That breach takes place at the cellular level. That is a different thing from the tooth erupting from the alveolar crypt.

Thanks, Harry for adding to the discussion.  I will need time to read and understand this paper for nuggets...

Here is another paper (2015) I need to read/understand:

https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0116557&type=printable

It certainly is complicated with lots of unknowns..

PaperEnamelWhale_Dolphin.JPG.971a39037d5715f71bdabbac4d086e62.JPG

 

The White Queen  ".... in her youth she could believe "six impossible things before breakfast"

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