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I bought these fossils a few months ago form a small rock shop in southern Utah, they were found in an assorted basket of small fossils likely bought in bulk along with ray barbs, gar scales, shark teeth, puffer mouth plates, barracuda teeth and shark verts. the store owner did not know what they were nor the location they were found. my guess would be the Chandler bridge Formation but I'm not sure. Looking for I identification if anyone knows what these are?   

 

 

Screenshot_2020-07-25-17-22-34.png   Screenshot_2020-07-25-17-22-44.png

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8 minutes ago, Xander509 said:

Looking for I identification if anyone knows what these are?    

Welcome to the forum !! .. these are Ray Dermal Denticals. To be fair they can be found all up and down the East Coast if that is, in fact, where they may have been found.

 

Cheers,

Brett

 

Image Credit: http://coastalpaleo.blogspot.com/2018/02/an-embarrassingly-enormous-dermal.html

Ray_Dermal_Dentical.thumb.JPG.cb019a47d602bc50d9646bb3e6630b61.JPG

Ashby Gale's enormous dermal denticle of "Ceratoptera unios", from the early Pleistocene Waccamaw Formation of South Carolina. CCNHM collections.

 

Ray_Dermal_Denticle.JPG.c78709e1592303d3ee925d5d3beaae77.JPG

Smaller denticles resembling Ceratoptera unios from the Pliocene Yorktown Formation, Lee Creek Mine, North Carolina, Rita McDaniel (CCNHM collections).

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6 minutes ago, Xander509 said:

Thank you Brett, much appreciated!

Sure .. here is an interesting discussion about them ..

 

And a great image of the various forms and shapes of these ray/skate denticles from Florida.

 

Image Credit: @digit

RayDenticles_TFF_digit.thumb.jpg.059bd838e5d26ec81a457e4fa067c8c5.jpg

 

 

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1 hour ago, Brett Breakin' Rocks said:

Sure .. here is an interesting discussion about them ..

 

And a great image of the various forms and shapes of these ray/skate denticles from Florida.

 

Image Credit: @digit

RayDenticles_TFF_digit.thumb.jpg.059bd838e5d26ec81a457e4fa067c8c5.jpg

 

 

Brett,

I do not know why it happened as a result of this post, but maybe you or other TFF members know the answers to these questions about Ray dermal denticles...

What is the design and process of attaching a barb to a dermal denticle? Does it attach to the bottom of the "key" or the top of the key? Is there a photo or drawing of a barb with the associated denticle?

To what extent has anyone associated a specific type of denticle to a specific Ray?  So, have we associated ANY denticles? (Seems like the answer is Yes for Ceratoptera unios on Bobby's blog), but my question really relates to can I look at a fossil denticle I found and go to a matching website that says a photo of that denticle is Manta, or Eagle, or Bonnet Ray, etc. ? We should ask @MarcoSr, @Al Dente@Boesse. Please add any others who might have valuable input.

For example, I find lots of these "Buttons"

What Ray or Rays produce them?

Buttons.JPG.9c3e1619620360914e66760a08beb42f.JPG

 

 

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

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26 minutes ago, Shellseeker said:

 

Brett,

I do not know why it happened as a result of this post, but maybe you or other TFF members know the answers to these questions about Ray dermal denticles...

What is the design and process of attaching a barb to a dermal denticle? Does it attach to the bottom of the "key" or the top of the key? Is there a photo or drawing of a barb with the associated denticle?

To what extent has anyone associated a specific type of denticle to a specific Ray?  So, have we associated ANY denticles? (Seems like the answer is Yes for Ceratoptera unios on Bobby's blog), but my question really relates to can I look at a fossil denticle I found and go to a matching website that says a photo of that denticle is Manta, or Eagle, or Bonnet Ray, etc. ? We should ask @MarcoSr, @Al Dente@Boesse. Please add any others who might have valuable input.

For example, I find lots of these "Buttons"

What Ray or Rays produce them?

Buttons.JPG.9c3e1619620360914e66760a08beb42f.JPG

 

 

Hey Jack ... I was always somewhat confused since there is no good visual reference for placement etc .. in my references. But if you look at modern X-rays you can see these denticles imbedded in the skin of the animal clearly. Though, finding a definitive guide for identification, if it exists, I haven't seen it. ie. there are probably  disparate references and papers but not a collection of references.

 

Image Credit: https://fm-digital-assets.fieldmuseum.org/705/237/FMNH_106065_Potamotrygon_motoro_ventral_x_ray_view_X855_IMG_0014.JPG

Creator: Mr. Kevin A. Swagel : Field Museum of Natural History
[Copyright] Field Museum of Natural History - CC BY-NC
Description: x-ray ventral view of FMNH 106065 Potamotrygon motoro (X855)

 

Stingray_Dermal_Denticles.jpg.ba6b502a43685ce5a21a7573f9d001ae.jpg

 

A skate. Xray photography credit: Nick Veasey (https://www.nickveasey.com)

Xray_Skate_001.png.1ba0d582d3708db92664339e7c0b0389.pngXray_Skate_001.thumb.jpg.09182797baa6a9810b3955d8aa70b9a7.jpg

 

Cheers,

Brett

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16 minutes ago, Brett Breakin' Rocks said:

Hey Jack ... I was always somewhat confused since there is no good visual reference for placement etc .. in my references. But if you look at modern X-rays you can see these denticles imbedded in the skin of the animal clearly. Though, finding a definitive guide for identification, if it exists, I haven't seen it. ie. there are probably  disparate references and papers but not a collection of references.

 

Image Credit: https://fm-digital-assets.fieldmuseum.org/705/237/FMNH_106065_Potamotrygon_motoro_ventral_x_ray_view_X855_IMG_0014.JPG

Creator: Mr. Kevin A. Swagel : Field Museum of Natural History
[Copyright] Field Museum of Natural History - CC BY-NC
Description: x-ray ventral view of FMNH 106065 Potamotrygon motoro (X855)

 

Thanks , Brett... :fistbump:  I know a little bit more than I did.

 

I see a few examples like this site, but nothing more general...

http://www.elasmo.com/research/pelagic/d_v-dent.html

@siteseer

 

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

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3 hours ago, Shellseeker said:

 

1)What is the design and process of attaching a barb to a dermal denticle? Does it attach to the bottom of the "key" or the top of the key? Is there a photo or drawing of a barb with the associated denticle?

 

2) To what extent has anyone associated a specific type of denticle to a specific Ray?  So, have we associated ANY denticles? (Seems like the answer is Yes for Ceratoptera unios on Bobby's blog), but my question really relates to can I look at a fossil denticle I found and go to a matching website that says a photo of that denticle is Manta, or Eagle, or Bonnet Ray, etc. ?

 

 

With respect to your second question ( 2) above ) there are lots of papers showing fossil ray dermal denticles.  However the dermal denticles are not usually assigned to specific ray families/genera/species unless the dermal denticles were found in association with other identifiable ray fossils like individual teeth or dental plates.  There really isn't a comprehensive publication that I'm aware of that describes extant ray dermal denticles.  Again you can find papers that show the dermal denticles for specific extant ray species being described.  I have lots of different ray tails and taxidermy rays and the dermal denticles can vary widely on a specific individual ray depending on the location of the dermal denticles on the ray.  The dermal denticles are usually found on the tails and body midlines but can be around the eyes or on the wing tips etc.  Also there is a lot of similarity between the dermal denticles of different extant ray genera/species which makes it very difficult to figure out the specific genera/species.

 

I don't understand your first question ( 1) above).  I have hundreds of pictures of extant ray dermal denticles embedded in ray tails and bodies.  If you are asking about that see the below pictures of dermal denticles in a couple of ray (skates) tails.

 

Dipturus oxyrinchus (Sharpnose Skate) tail female:

 

5f56e02f129cc_Dipturusoxyrinchus(SharpnoseSkate)tailfemale85cm15inchesby1.25inchesendbybodydorsal.thumb.jpg.c2aaeeac2915fdf9d467a647f6da0866.jpg

 

5f56e035ecab9_Dipturusoxyrinchus(SharpnoseSkate)tailfemale85cm15inchesby1.25inchesmiddleoftaildorsal.thumb.jpg.32d88abf8d791868eb5e99a5f5f8f2ec.jpg

 

5f56e032038de_Dipturusoxyrinchus(SharpnoseSkate)tailfemale85cm15inchesby1.25inchesendoftaildorsal.thumb.jpg.c2cb0ddbefe748835193b21eb86579ca.jpg

 

Platyrhinoidis  triseriata (Thornback Fanray) tail female:

 

5f56e1417f8e3_Platyrhinoidistriseriata(ThornbackFanray)femaledisc6inchlongby7inchwidetail9.5inchlongrowsofdermalthornsonbaseoftaildorsal.jpg.621446574779bbf86d78492242661006.jpg

 

5f56e144435a6_Platyrhinoidistriseriata(ThornbackFanray)femaledisc6inchlongby7inchwidetail9.5inchlongtotallength16inches1stdorsalfindorsal.jpg.1904436e260e0f39d0a9e394e3208956.jpg

 

Raja clavata tail female:

 

5f56e23135d31_Rajaclavatafemale81cmtail14inches1.375inchesdorsal.thumb.jpg.2d7d751d7b729d064fe7852fe068eaff.jpg

 

5f56e234468c2_Rajaclavatafemale81cmtail14inches1.375inchesmidtailmid-linethorndorsal.jpg.9daa8b877c3fdaecc068eb6dbb43f906.jpg

 

5f56e22d84e45_Rajaclavatafemale81cmtail14inches1.375inchesdorsalRthorn.thumb.jpg.c1116ec8890e8eb2509dd94a917fdf3d.jpg

 

Beringraja inornata (California Skate) tail female:

 

5f56e3410fa09_Beringrajainornata(CaliforniaSkate)tailfemale39.2cm6inchesby.5inchesatbodyendoftaildorsal.jpg.07cb64a4b23ce3e764dfefe1f6128701.jpg

 

 

Marco Sr.

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"Any day that you can fossil hunt is a great day."

My family fossil website     Some Of My Shark, Ray, Fish And Other Micros     My Extant Shark Jaw Collection

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On 9/7/2020 at 9:54 PM, MarcoSr said:

I don't understand your first question ( 1) above).  I have hundreds of pictures of extant ray dermal denticles embedded in ray tails and bodies.  If you are asking about that see the below pictures of dermal denticles in a couple of ray (skates) tails.

 

Thank you for the response.  It may be my mistake in what is a "Dermal denticle". Across the last decade I have found thousands of what I believed to be dermal denticles, almost none of which were less than 10 mm -- because something that small would frequently fall thru my sieve. I do not believe that I have ever found a denticle similar to the one in your photos.

I find fossils like these, 1000s of them over the years. Some days I find 15-20 of them. Many, Many, Many variations. Very few are over 2 inches but I have found those also. They are all over the place, Bone Valley, Peace River, and all creeks that are Peace River tributaries. There are numerous different types and as you can see, they are very distinctive.

5f56ef304967f_post-42-0948707001285357586.jpg.f04c3558b7855152d1117324c3b38930.jpg

 

See Brett's photo of Florida dermal denticles above  to see other forms.

 

image.thumb.png.3784a80eabcc7b8766d6f547ae8babf0.png

 

This was the 1st fossil of this type I ever found, and some one told me that it was a "Dermal Denticle". I also came to believe at the time that Ray Barbs and and smaller spines in the tail and rest of the body would be "anchored" in such Dermal Denticles

image.png.cf3c1eb1de86e2c30cf490b117fc09e1.png

Here is a thread that introduced me to Dermal Denticles 10 years ago.

http://www.thefossilforum.com/index.php?/topic/15762-ray-dermal-denticles/

 

So, now my questions: rephrased

1) As I indicated , I had believed that Ray Barbs, and other spines attached to these Dermal Denticles as a Base.  That could be pure "FuFu dust". Maybe they do not... I admittedly never saw a picture of how a barb/spine attached to a denticle.  The "key" is the dark enamel part of these 2 denticles.

DermalDenticleKey.JPG.93914be9babb12b290059786a8cc54fc.JPG

On 9/7/2020 at 7:34 PM, Brett Breakin' Rocks said:

What is the design and process of attaching a barb to a dermal denticle? Does it attach to the bottom of the "key" or the top of the key? Is there a photo or drawing of a barb with the associated denticle?

2) To what extent has anyone associated a specific type of denticle  to a specific Ray?  So, have we associated ANY denticles?

I should have clarified this as the Miocene Denticles I have found in Florida. Truthfully, I thought that these types of fossils were being found in multitudes on the East Coast of the US.

 

Hopefully, this response at least clarifies my questions... Jack

 

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

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Hi,

 

3 hours ago, Shellseeker said:

I admittedly never saw a picture of how a barb/spine attached to a denticle.

 

The spines aren't attached to the dermal denticles, I think they are attached and held under the skin by muscles.


Coco

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OUTIL POUR MESURER VOS FOSSILES : ici

Ma bibliothèque PDF 1 (Poissons et sélaciens récents & fossiles) : ici
Ma bibliothèque PDF 2 (Animaux vivants - sans poissons ni sélaciens) : ici
Mâchoires sélaciennes récentes : ici
Hétérodontiques et sélaciens : ici
Oeufs sélaciens récents : ici
Otolithes de poissons récents ! ici

Un Greg...

Badges-IPFOTH.jpg.f4a8635cda47a3cc506743a8aabce700.jpg Badges-MOTM.jpg.461001e1a9db5dc29ca1c07a041a1a86.jpg

 

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10 hours ago, Shellseeker said:

 

So, now my questions: rephrased

1) As I indicated , I had believed that Ray Barbs, and other spines attached to these Dermal Denticles as a Base.  That could be pure "FuFu dust". Maybe they do not... I admittedly never saw a picture of how a barb/spine attached to a denticle.  The "key" is the dark enamel part of these 2 denticles.

DermalDenticleKey.JPG.93914be9babb12b290059786a8cc54fc.JPG

 

2) To what extent has anyone associated a specific type of denticle  to a specific Ray?  So, have we associated ANY denticles?

I should have clarified this as the Miocene Denticles I have found in Florida. Truthfully, I thought that these types of fossils were being found in multitudes on the East Coast of the US.

 

 

None of the pictures that you have posted are ray barbs.  They are all enlarged dermal denticles which typically are along a ray's mid-line.  The dermal denticles that I see on the extant small species of rays that I have are all much smaller than the ones you have posted and look like the ones in the pictures that I posted earlier.  Dermal denticles are a form of armor to prevent predators from biting down on the ray.  What is defined as a ray barb is totally different.  Only some ray families have them.  They are called sting rays.  The barbs are used as a weapon to impale an attacker.  Usually ray species that have ray barbs have a single barb near the base of the tail although some species can have as many as three barbs at the base of the tail.  They are attached under the skin.  Below are some pictures of individual extant ray tails/barbs and an extant great hammerhead jaw with an embedded ray barb.

 

Myliobatis californicus (Bat Eagle Ray) tail female:

 

s-l503.jpg.906c5f96961674b697d2e22d4dd90a7e.jpg

 

5f5762db701bc_Myliobatiscalifornicus(BatEagleRay)femalebody9inchesby16inchestail18inchescaudalsting1.875inchesdorsal.thumb.jpg.0a767e6a6405a529643f656b2407884b.jpg

 

 

Urolophus aurantiacus (Oriental Stingaree) tail male:

 

s-l505.jpg.a3d33200be928799c3b2b4f55132ce0d.jpg

 

5f5763a62c7ca_Urolophusaurantiacus(OrientalStingaree)maledisc5.75inchesby6.5inchestail5.75inchescaudalsting1.625inchesdorsal.thumb.jpg.3bfdafcc42c3dfb31b0668e726607220.jpg

 

 

Urotrygon microphthalmum (Smalleye Round Ray) tail female:

 

s-l70.jpg.d149c4e3b8fa58a910b96538938e4a5f.jpg

 

5f57643aba15a_Urotrygonmicrophthalmum(SmalleyeRoundRay)femaledisc6inchesby6inchestail6inchescaudalspine1.75inchesdorsal.thumb.jpg.763c366fe1eed4c536afb19ad0e31e20.jpg

 

 

Sphyrna mokarran (Great Hammerhead Shark) jaw with an embedded ray barb:

 

5f5767524cd50_Sphyrnamokarran(GreatHammerheadShark)1rayspinerightsidelowerjawLabialview.thumb.jpg.0c982290aded12d040543d0bb8eec050.jpg

 

 

I already answered your second question in an earlier post above.

 

EDIT:  See the below illustration from Hulbert, Jr.  2001 Fossil Vertebrates of Florida (Note that a lot of shark and ray terminology has not been standardized and different researchers use different terminology like dermal denticle aka dermal spines aka dermal thorns etc.) :

 

5f5781f5c2494_DermalDenticlesfromHulbertJr.2001FossilVertebratesofFlorida.thumb.jpg.be89d1f8e7d7ae21ba75bc74d72d5066.jpg

 

 

Marco Sr.

Edited by MarcoSr
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"Any day that you can fossil hunt is a great day."

My family fossil website     Some Of My Shark, Ray, Fish And Other Micros     My Extant Shark Jaw Collection

image.png.9a941d70fb26446297dbc9dae7bae7ed.png image.png.41c8380882dac648c6131b5bc1377249.png

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Great educational post!! I now know my ray anatomy MUCH better and can look at my only ray dermal denticle in a different light!!

 

 Mike

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3 hours ago, MarcoSr said:

None of the pictures that you have posted are ray barbs.  They are all enlarged dermal denticles which typically are along a ray's mid-line.  The dermal denticles that I see on the extant small species of rays that I have are all much smaller than the ones you have posted and look like the ones in the pictures that I posted earlier.  Dermal denticles are a form of armor to prevent predators from biting down on the ray.  What is defined as a ray barb is totally different.  Only some ray families have them.  They are called sting rays.  The barbs are used as a weapon to impale an attacker.  Usually ray species that have ray barbs have a single barb near the base of the tail although some species can have as many as three barbs at the base of the tail.  They are attached under the skin.  Below are some pictures of individual extant ray tails/barbs and an extant great hammerhead jaw with an embedded ray barb.

 

Thank you,

Like Mike, I learned a lot about ray barbs today, and I sure you are aware, your photos are a outstanding educational tool that fixes an image in the mind.  I am somewhat stunned that I had this completely incorrect notion, but I recognize that it is one more weakness in the way I learn about different fossils, skimming rather than in depth. I had huge success in life and business by a tendency to make decisions quickly on minimal information and triage the errors after the fact if necessary.

Bobby's blog link above had a photo of one of these enlarged dermal denticles inscription:

An actual caudal stinger of a manta ray, Manta birostris (or Manta hynei), from the Pliocene Yorktown Formation, Lee Creek Mine, North Carolina, Rita McDaniel (CCNHM collections).

 

Again , from Bobby's blog

Quote

One such curiosity is the case of “Ceratoptera unios” – a species named by none other than preeminent American paleontologist Joseph Leidy in 1877 in a monograph on fossil vertebrates from the Ashley Phosphate Beds of Charleston, South Carolina. “Ceratoptera” – horn-wing – is now of course a junior synonym of the genus Manta – manta rays. Leidy examined this enormous dermal denticle, measuring 82 mm long, 54 mm wide, and 36 mm in thickness. There’s no way around it: this thing is a massive hunk of… osteodentine, I would assume? It is oval in shape with a flat bottom, mound-like, with a triangular enameloid scale that narrows towards the central apex of the denticle. Leidy, judging from the embarrassingly large size of this thing, named it as a new species and identified as a caudal stinger of a manta ray.

 

What is a "caudal stinger" of a Manta Ray? The enlarged Dermal Denticle does not look like it could "sting" anything.

 

On the 2nd question, I was after something very specific. Has anyone done a scientific study on Miocene enlarged dermal denticles to connect them to the specific species of Ray or Skate. The answer seems to be a resounding No. No info from Richard Hulbert, No presence of scientific papers on the Internet from Lee Creek, Calvert, Bone Valley,  none. No one popping up on this forum or any other  (Elasmo,,) saying "here is a enlarged dermal denticle . It belongs to this Miocene Ray".

 

An excellent thread from @siteseer in the 2010 TFF thread:

Quote

Harry,

All those dermal denticles fit within the morphological range of stingrays, Dasyatis, according to Purdy et al. (2001: 92). They went a step further with identical material from the Yorktown Formation, referring it to the species, D, centroura.

For years I had seen these identified as "skate dermal denticles" and I'd always wondered about the ID because I had never read about how the distinction was made. That seemed to be how similar finds from STH or Ridgeville (South Carolina) were also tagged. I had never seen stingray or true skate teeth from the Bone Valley Formation and the book "The Fossil Vertebrates of Florida" (Wing in Hulbert, 2001) offers no assistance as it doesn't adequately figure any ray teeth except for those of some myliobatids.

Years ago, while prepping a Bone Valley dolphin skull in its field jacket, I saved the matrix out of habit and later screened it. I did find a couple of stingray teeth and some kind of guitarfish as well (possibly Rhynchobatus). It would seem unlikely that skates would be known from the Bone Valley Formation as the fauna indicates warm-water/shallow water forms while skates generally frequent cool water/deeper water.

Wing (in Hulbert, 2001) stated that "skate teeth are small and buttonlike." More precise adjectives are required for skate teeth as some are quite small, as in around 1mm long. Female teeth tend to bear lower-cusped crowns while male teeth have tall, pointed crowns like sharks, though not in all species with jaw position sometimes a factor as well (see Herman et al, 1995).

Herman, J., M. Hovestadt-Euler, D.C. Hovestadt, and M. Stehmann. 1995.

Part B. Batomorphii No. 1b: Order Rajiformes - Suborder Rajoidei - Family: Rajidae - Genera and Subgenera: Bathyraja (with deep-water, shallow-water and transitional morphotype), Psammobatis, Raja (Amblyraja), Raja (Dipturus), Raja (Leucoraja), Raja (Raja), Raja (Rajella) (with two morphotypes), Raja (Rioraja), Raja (Rostroraja), Raja lintea, and Sympterygia. In M. Stehmann. Contributions to the study of the comparative morphology of teeth and other relevant ichthyodorulites in living supra-specific taxa of Chondrichthyan fishes. Bulletin de l'Institut Royal des Sciences Naturelles de Belgique. Biologie 65: 237-307.

 

So the question rolling around in my mind is WHY..  Why do I know so much about the Physogaleus contortus tooth in the same sieve last Friday as a couple of enlarged dermal denticles?

__Is it just due to a lack of study?  We could have the answer, but no one is investing in the answer.

__Is it that these enlarge dermal denticles primarily exist in few locations (like Bone Valley) in multitudes?

__Is it because Ray/Skate bodies/skeletons are never found intact like that 2014 Hemipristis? This Halloween, the Gibson family in Chesapeake Bay, Maryland, had a surprising visit from the dead. While digging a foundation for the construction of his parent’s sunroom, Donald Gibson unearthed the 15-million-year-old grave of a snaggletooth shark. It’s also the most complete fossilized skeleton of the species ever found, including roughly 80 vertebrae and hundreds of teeth.

 

I'll have to consider the question of why . It may take some time.

 

 

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

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2 hours ago, Shellseeker said:

What is a "caudal stinger" of a Manta Ray? The enlarged Dermal Denticle does not look like it could "sting" anything.

Here's a drawing of a modern Manta with it's caudal sting. The actual "stinger" is reduced to a couple millimeters, making the stinger useless. Large pelagic rays no longer need stingers since stingers work best when the ray is resting on the bottom where it can thrust upward toward a predator.

 

 

mantacaudal.JPG

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Some info:

"Caudal Spine"  does not get a lot of hits on an internet search,  plus even scientific papers seem to view it as interchangeable with "Stingray Barb".CaudalSpine.JPG.c35655f535f1110f9d104d4b349388f6.JPG

 

There are clearly many "enlarged caudal spines" at Lee Creek Mine, I have found all of these types in Bone Valley.  These types seem to have dispensed with the need for a Stingray Barb.

 

5f57e018ae9da_IMG_9849LCM_caudal_stinger_MantabirostrisSmaller.JPG.ce5e8d8957490d5ca82caedf50a02042.JPG

 

However , this one Ceratoptera unios from the Pliocene of South Carolina, seems like it could have functioned as a backstop for a Stingray Barb.

 

Ceratoptera_unios_Leidy1876withredBarb.JPG.c6d12592ba433979ff2ed19bcac93cc2.JPG

 

From any and all of the papers on the Internet, I was most impressed on Bobby's Blog entry on Feb 9th, 2018, which ended with

Quote

 Are Ceratoptera unios and Dasyatis centroura synonyms? Maybe – although for once, we don’t need any more fossils; we need more dissections and comparative studies of dermal elements to be published by ichthyologists!

 

http://coastalpaleo.blogspot.com/2018/02/an-embarrassingly-enormous-dermal.html

 

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

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16 minutes ago, Shellseeker said:

There are clearly many "enlarged caudal spines" at Lee Creek Mine, I have found all of these types in Bone Valley.  These types seem to have dispensed with the need for a Stingray Barb.

The denticles you are showing are from the midline of the stingray, probably from Bathytoshia (used to be Dasyatis) centroura. These are not the same as the stinger which is from the tail of a stingray and is designed to be easily pulled out from the tail into the flesh of a predator. Here’s a photo of Bathytoshia centroura showing the large denticles that occur all over the back of larger specimens.

 

 

8CD6136F-5F19-4515-BD8C-2AAC863E148D.jpeg

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4 minutes ago, Shellseeker said:

Some info:

"Caudal Spine"  does not get a lot of hits on an internet search,  plus even scientific papers seem to view it as interchangeable with "Stingray Barb".CaudalSpine.JPG.c35655f535f1110f9d104d4b349388f6.JPG

 

There are clearly many "enlarged caudal spines" at Lee Creek Mine, I have found all of these types in Bone Valley.  These types seem to have dispensed with the need for a Stingray Barb.

 

5f57e018ae9da_IMG_9849LCM_caudal_stinger_MantabirostrisSmaller.JPG.ce5e8d8957490d5ca82caedf50a02042.JPG

 

However , this one Ceratoptera unios from the Pliocene of South Carolina, seems like it could have functioned as a backstop for a Stingray Barb.

 

Ceratoptera_unios_Leidy1876withredBarb.JPG.c6d12592ba433979ff2ed19bcac93cc2.JPG

 

From any and all of the papers on the Internet, I was most impressed on Bobby's Blog entry on Feb 9th, 2018, which ended with

 

http://coastalpaleo.blogspot.com/2018/02/an-embarrassingly-enormous-dermal.html

 

 

Like I said in an above post, shark and ray terminology has not been standardized.  You are getting confused by researchers using different terms for the same thing and the same term for different things. Below I discus three different things based upon their function.

 

Offensive weapon at the base of the ray tail to impale a predator:  caudal sting, ray barb, caudal spine, stinger etc. all refer to the same thing.

 

Armor to protect the ray when being bitten by a predator or thorns to cause a predator not to bite in the first place:  dermal denticle, dermal spine, dermal thorn all refer to the same thing.  Enlarged dermal denticle, scute etc. are used for a very large dermal denticle.

 

Help the ray glide through the water:  Some ray families also have very small dermal denticles (like sharks which are used to lessen water resistance) usually smaller than 1 millimeter, which researchers call either placoid scales or dermal denticles.

 

Marco Sr.

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"Any day that you can fossil hunt is a great day."

My family fossil website     Some Of My Shark, Ray, Fish And Other Micros     My Extant Shark Jaw Collection

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I am pretty comfortable in the concept that Stingray Barbs are not associated with "enlarged dermal denticles".

2 hours ago, Al Dente said:

The denticles you are showing are from the midline of the stingray, probably from Bathytoshia (used to be Dasyatis) centroura. These are not the same as the stinger which is from the tail of a stingray and is designed to be easily pulled out from the tail into the flesh of a predator. Here’s a photo of Bathytoshia centroura showing the large denticles that occur all over the back of larger specimens.

This is the key....forgetting the discussion about barbs.

Can we take Enlarged Dermal Denticles found in Lee Creek Mine  image.png.5963db6cdefe39c5b74ba197e4177612.png

and associate them with specific species:, identifying any research/papers that already do that?

image.png.39e853e2b4f85b7d57a17ff6082cd55c.png

 

Can we reproduce that process at any locations that have Rays/Skates, like Bone Valley ?

 

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

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9 hours ago, Shellseeker said:

Can we take Enlarged Dermal Denticles found in Lee Creek Mine  image.png.5963db6cdefe39c5b74ba197e4177612.png

and associate them with specific species:, identifying any research/papers that already do that?

Yes. The Smithsonian publication “Geology and Paleontology of the Lee Creek Mine” identifies these as coming from “Dasyatis” centroura with photos of modern and fossil examples.

 

 

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22 hours ago, Shellseeker said:

So the question rolling around in my mind is WHY..  Why do I know so much about the Physogaleus contortus tooth in the same sieve last Friday as a couple of enlarged dermal denticles?

Because as avocational paleontologists (aka amateur fossil hunters) our knowledge of fossil types comes piecemeal--usually in response to some novel fossil we've found. We grow the envelope of our knowledge base by researching the types of fossils available and frequently found by us. Most Florida fossil hunters (generally speaking) know relatively little of Pennsylvanian fern fossils (the reason may be hinted at in the name of that epoch) and tend to have only a passing knowledge of theropod dinosaur teeth (other than what we glean from this forum).

 

It is greatly satisfying to be able to push out the edges of our knowledge bubble when a knowledge deficit occurs to us. How do you distinguish the teeth of the extant Tiger Shark species from those of its purported ancestral lineage? What is the function, placement, and taxonomic association of the dermal denticles we pick out of our sifting screens? Being able to pose a question here on the forum and then find responses from other members to help fill in the knowledge gaps is one of the greatest benefits of the forum for me (and I suspect many others).

 

22 hours ago, Shellseeker said:

Wing (in Hulbert, 2001) stated that "skate teeth are small and buttonlike." More precise adjectives are required for skate teeth as some are quite small, as in around 1mm long. Female teeth tend to bear lower-cusped crowns while male teeth have tall, pointed crowns like sharks, though not in all species with jaw position sometimes a factor as well (see Herman et al, 1995).

As an added aside to this dermal denticle thread, I'll drop a little packet of (unrelated) knowledge in case it benefits others. I recently found a tiny skate tooth while picking Montbrook micro-matrix. I noticed its distinction from the many stingray (Dasyatis sp.) teeth because of what I'd learned from @Al Dente some years back when skate teeth turned up in Cookiecutter Creek micro-matrix. Tthe black tooth is from CC Creek and the colorful one is from Montbrook. They are "small and buttonlike" indeed (scale markings 0.5 mm). ;)

 

Cheers.

 

-Ken

 

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16 hours ago, Al Dente said:

Yes. The Smithsonian publication “Geology and Paleontology of the Lee Creek Mine” identifies these as coming from “Dasyatis” centroura with photos of modern and fossil examples.

Thank you..  This is fantastic!!!! :SlapHands:

Imagine if there were an equivalent paper for most/all of the Miocene/Pliocene Rays/Skates. Out of this thread , I had already decided to search for papers exactly like this one.

I will be very interested in the process used to match the dermals to a specific Ray.

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

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So my two cents regarding large denticles and my post on "Ceratoptera unios" - I thought I was more explicit on my blog, but those giant denticles are midline denticles of Dasyatis centroura. Ones that massive have never been reported from the Lee Creek Mine - and most that are extremely thick and pyramid like are all from Charleston, SC for some reason. Leidy wrongly thought they were Manta caudal stingers, which are potato shaped and have a very short enameloid stinger without barbs.

 

Part of the reason I've not yet written up that huge denticle we found is because of the lack of comparative anatomical studies of these things in modern batoids - though the Dasyatis centroura identification is probably good enough for a short paper clarifying the stratigraphic origin of these things (since Leidy's original specimen lacked stratigraphic provenance).

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