PaleoRon Posted March 22, 2009 Share Posted March 22, 2009 After seeing some ray material on other posts I decided to post some of my ray plates and sawfish specimens. Paleocene. Aquia formation. Eocene. Nanjemoy formation. Miocene/Pliocene. Bone Valley formation. Eocene. Sawfish rostral spines. Link to comment Share on other sites More sharing options...
Auspex Posted March 22, 2009 Share Posted March 22, 2009 The other Elasmos. All I ever found were partial (with one exception) plates, dermal ossicles, and barbs (all Calvert Fm.). What's the truth about these putative "venom sacs"? I've read conflicting interpretations... Also, who was it that posted a pic (quite a while ago) of a shark's tooth with a barb embeded in the root? I'd like to see that again. "There has been an alarming increase in the number of things I know nothing about." - Ashleigh Ellwood Brilliant “Try to learn something about everything and everything about something.” - Thomas Henry Huxley >Paleontology is an evolving science. >May your wonders never cease! Link to comment Share on other sites More sharing options...
PaleoRon Posted March 22, 2009 Author Share Posted March 22, 2009 The other Elasmos.All I ever found were partial (with one exception) plates, dermal ossicles, and barbs (all Calvert Fm.). What's the truth about these putative "venom sacs"? I've read conflicting interpretations... Also, who was it that posted a pic (quite a while ago) of a shark's tooth with a barb embeded in the root? I'd like to see that again. I have seen a tooth with a definite ray barb sticking out about 1/4 inch from both sides. It was an excellent specimen of species interaction. I'm not sure what the deal is with the "venom sacks". I have found a couple complete ones and the spine was less than 1/2 inch. Also, I found a broken one and it was completely solid. There was no "sack" inside. I have been told that the big ones are from manta rays. Link to comment Share on other sites More sharing options...
fossilselachian Posted March 22, 2009 Share Posted March 22, 2009 The other Elasmos.All I ever found were partial (with one exception) plates, dermal ossicles, and barbs (all Calvert Fm.). What's the truth about these putative "venom sacs"? I've read conflicting interpretations... Also, who was it that posted a pic (quite a while ago) of a shark's tooth with a barb embeded in the root? I'd like to see that again. Auspex: Months ago I posted a 4" C. angustidens with a sting ray barb which had penetrated the lingual protuberance of the tooth. It emerged from the bottom of the protuberance and also from the base of the root lobes. If this is the one to which you made reference, I'll try again post the pics. FS Link to comment Share on other sites More sharing options...
Auspex Posted March 22, 2009 Share Posted March 22, 2009 Auspex:Months ago I posted a 4" C. angustidens with a sting ray barb which had penetrated the lingual protuberance of the tooth. It emerged from the bottom of the protuberance and also from the base of the root lobes. If this is the one to which you made reference, I'll try again post the pics. FS It probably was; I only recall one ever being posted. Hope you can re-post! "There has been an alarming increase in the number of things I know nothing about." - Ashleigh Ellwood Brilliant “Try to learn something about everything and everything about something.” - Thomas Henry Huxley >Paleontology is an evolving science. >May your wonders never cease! Link to comment Share on other sites More sharing options...
Carl O'Cles Posted March 22, 2009 Share Posted March 22, 2009 Auspex:Months ago I posted a 4" C. angustidens with a sting ray barb which had penetrated the lingual protuberance of the tooth. It emerged from the bottom of the protuberance and also from the base of the root lobes. If this is the one to which you made reference, I'll try again post the pics. FS Please re-post i'd like to see that Link to comment Share on other sites More sharing options...
Carl O'Cles Posted March 22, 2009 Share Posted March 22, 2009 Nice plates you got there ron. I've gotten a good deal of them from the Eocene and Paleocene as well but i have found it exceedingly hard to find plates from the Miocene in only having found 2-3 complete ones. Just curious if others have had the same experience. Link to comment Share on other sites More sharing options...
PaleoRon Posted March 22, 2009 Author Share Posted March 22, 2009 Nice plates you got there ron. I've gotten a good deal of them from the Eocene and Paleocene as well but i have found it exceedingly hard to find plates from the Miocene in only having found 2-3 complete ones. Just curious if others have had the same experience. I have found several partials from the Miocene but only 3 that are more than 50% complete. Link to comment Share on other sites More sharing options...
PaleoRon Posted March 23, 2009 Author Share Posted March 23, 2009 More ray plates. Paleocene. Aquia formation. Eocene. Morocco. Miocene. Calvert formation. Pliocene. Yorktown formation. Link to comment Share on other sites More sharing options...
fossilselachian Posted March 23, 2009 Share Posted March 23, 2009 Auspex: Is this the one? Attached are pics of a 4.0" deformed Carcharocles angustidens from Summerville, SC. In this case the reason for the deformity is known. A sting ray barb has penetrated the root of the tooth resulting in a much distorted torus (lingual protuberance) of the tooth. The first pic is an overall view of the tooth and one end of the barb can be seen emerging just above the bourlette. The second pic is a close-up of the same end of the barb. In the third pic, the other tip of the barb can be seen emerging just to the right of the center line of the root in labial aspect. It's somewhat difficult to see from the pictures the high degree of root deformity caused by the barb. Also, the barb has fossilized the same color as the root. In hand, the barb can be seen more clearly than in the photos. I once took the tooth to my dentist to see if he could get an X-ray of the barb along the entire length of root penetration. Unfortunately the tooth material was of such density that the X-rays were not successful. Link to comment Share on other sites More sharing options...
Auspex Posted March 23, 2009 Share Posted March 23, 2009 Auspex: Is this the one? Yes it is! That fossil has been popping into my head now and again ever since you first posted it; a real story teller! "There has been an alarming increase in the number of things I know nothing about." - Ashleigh Ellwood Brilliant “Try to learn something about everything and everything about something.” - Thomas Henry Huxley >Paleontology is an evolving science. >May your wonders never cease! Link to comment Share on other sites More sharing options...
Carl O'Cles Posted March 23, 2009 Share Posted March 23, 2009 More ray plates.Paleocene. Aquia formation. Eocene. Morocco. Miocene. Calvert formation. Pliocene. Yorktown formation. Great stuff, i really like the one from morocco Link to comment Share on other sites More sharing options...
Carl O'Cles Posted March 23, 2009 Share Posted March 23, 2009 Auspex: Is this the one? Attached are pics of a 4.0" deformed Carcharocles angustidens from Summerville, SC. In this case the reason for the deformity is known. A sting ray barb has penetrated the root of the tooth resulting in a much distorted torus (lingual protuberance) of the tooth. The first pic is an overall view of the tooth and one end of the barb can be seen emerging just above the bourlette. The second pic is a close-up of the same end of the barb. In the third pic, the other tip of the barb can be seen emerging just to the right of the center line of the root in labial aspect. It's somewhat difficult to see from the pictures the high degree of root deformity caused by the barb. Also, the barb has fossilized the same color as the root. In hand, the barb can be seen more clearly than in the photos. I once took the tooth to my dentist to see if he could get an X-ray of the barb along the entire length of root penetration. Unfortunately the tooth material was of such density that the X-rays were not successful. Nice piece you have there, did you notice the barb right away or did you think the tooth was just a pathy when you first found it? Link to comment Share on other sites More sharing options...
Pristiformes Posted March 23, 2009 Share Posted March 23, 2009 Nice batoid specimens Ron! Oh, and I forgot who suggested that the large caudal spines are from mantas, but the modern giant manta (Manta birostris) actually has no caudal spine at all! The larger caudal spines I have seen on living rays have been on large Dasyatid rays (whiptail rays) and eagle rays. The spines of dasyatids reach close to 12 inches in length. Incidentally, at least some rays, such as the Atlantic stingray, shed their caudal spines each year and regrow new ones. Also, the venom associated with a caudal spine (or barb) is generated within a thin integument that covers the whole spine when it is on a living ray. The protein-based toxic is generated within the integument of the spine itself and not in any "venom sack". When the spine penetrates another animal the integument tears, releasing the toxin into the wound instantaneously. Link to comment Share on other sites More sharing options...
Carl O'Cles Posted March 23, 2009 Share Posted March 23, 2009 Incidentally, at least some rays, such as the Atlantic stingray, shed their caudal spines each year and regrow new ones. Never knew this, thanks for sharing Link to comment Share on other sites More sharing options...
PaleoRon Posted March 23, 2009 Author Share Posted March 23, 2009 Nice batoid specimens Ron! Oh, and I forgot who suggested that the large caudal spines are from mantas, but the modern giant manta (Manta birostris) actually has no caudal spine at all! The larger caudal spines I have seen on living rays have been on large Dasyatid rays (whiptail rays) and eagle rays. The spines of dasyatids reach close to 12 inches in length. Incidentally, at least some rays, such as the Atlantic stingray, shed their caudal spines each year and regrow new ones. Also, the venom associated with a caudal spine (or barb) is generated within a thin integument that covers the whole spine when it is on a living ray. The protein-based toxic is generated within the integument of the spine itself and not in any "venom sack". When the spine penetrates another animal the integument tears, releasing the toxin into the wound instantaneously. The Manta theory didn't make much sense to me. I didn't think modern ones had any spines. Here are the two largest "spine like" fossils that I have found. These "spine bases" are really outsized because a complete one I found had a spine jutting off of it that was only around 1/2 inch. Broken base of spine Link to comment Share on other sites More sharing options...
Auspex Posted March 23, 2009 Share Posted March 23, 2009 Here are the two largest "spine like" fossils that I have found. These "spine bases" are really outsized because a complete one I found had a spine jutting off of it that was only around 1/2 inch. Well, good grief. I have a bunch of these and never bothered to figure them out; just tossed them in the Tilly box. "There has been an alarming increase in the number of things I know nothing about." - Ashleigh Ellwood Brilliant “Try to learn something about everything and everything about something.” - Thomas Henry Huxley >Paleontology is an evolving science. >May your wonders never cease! Link to comment Share on other sites More sharing options...
fossilselachian Posted March 23, 2009 Share Posted March 23, 2009 Nice piece you have there, did you notice the barb right away or did you think the tooth was just a pathy when you first found it? I must admit I did not find the tooth. The fellow who found the tooth recognized the obvious deformity but did not pick up on the reason why. I was reasonably sure the cause was a sting ray barb and told him as such. However, since the tooth was not "perfect" he was not interested and I believe I traded him something for the tooth. I've had it about 15 years. I once had the opportunity to show the tooth to Bruce Welton (Fossil Sharks and Rays from the Cretaceous of Texas) and he confirmed the presence of the barb. Link to comment Share on other sites More sharing options...
Pristiformes Posted March 23, 2009 Share Posted March 23, 2009 I must admit I did not find the tooth. The fellow who found the tooth recognized the obvious deformity but did not pick up on the reason why. I was reasonably sure the cause was a sting ray barb and told him as such. However, since the tooth was not "perfect" he was not interested and I believe I traded him something for the tooth. I've had it about 15 years. I once had the opportunity to show the tooth to Bruce Welton (Fossil Sharks and Rays from the Cretaceous of Texas) and he confirmed the presence of the barb. Neat pathological tooth. The story behind it is also interesting. I have seen stingray caudal spines enbedded in the jaws of many sharks (lemons, great hammerheads, bulls to name a few) and even a ray (Dasyatis americana jaw had a stingray spine stuck in the cartilage) while I was cleaning/prepping the jaw for curing. I have left the spines in some jaws for interests sake. But I've never seen a tooth with a spine in it. Cool stuff. Link to comment Share on other sites More sharing options...
Bill Posted March 23, 2009 Share Posted March 23, 2009 Ron, are they ray "spine bases" or large dermal denticles? KOF, Bill. Welcome to the forum, all new members www.ukfossils check it out. Link to comment Share on other sites More sharing options...
PaleoRon Posted March 23, 2009 Author Share Posted March 23, 2009 Ron,are they ray "spine bases" or large dermal denticles? They could very well be dermal denticles/ossicles. I've always heard them called venom sacks and it's obvious that they aren't that. If they are actually spine bases it seems that the spine should be huge and not tiny like it is. I have never seen a modern equivalent so I don't know what the anatomical position of the structure is, but I wish I did. One interesting thing is that there is very little variation in the shape of the specimens that I have seen and the two I posted are close to opposite extremes - elongated vs thick oval. Most of the ones I have found are the elongated form. Link to comment Share on other sites More sharing options...
Carl O'Cles Posted March 23, 2009 Share Posted March 23, 2009 However, since the tooth was not "perfect" he was not interested and I believe I traded him something for the tooth. I've had it about 15 years. WOW, i could never let a tooth like that go, you got a good deal there Link to comment Share on other sites More sharing options...
Bill Posted March 23, 2009 Share Posted March 23, 2009 They could very well be dermal denticles/ossicles. I've always heard them called venom sacks and it's obvious that they aren't that. If they are actually spine bases it seems that the spine should be huge and not tiny like it is. I have never seen a modern equivalent so I don't know what the anatomical position of the structure is, but I wish I did. One interesting thing is that there is very little variation in the shape of the specimens that I have seen and the two I posted are close to opposite extremes - elongated vs thick oval. Most of the ones I have found are the elongated form. Here are some Eocene Guitar fish (Hypolophodon sylvestris) denticles, alongside one from a recent, Thornback Ray (Raja clavata) A lot smaller than yours though. I always think of ray 'spines' as those from the likes of stingrays, though others might consider the 'thorns' or denticles, as spines. Here is a link to a good pic of a thornback, showing denticles around the tail and down the centre of its back. They are also dotted in various places all over the back, in various sizes. KOF, Bill. Welcome to the forum, all new members www.ukfossils check it out. Link to comment Share on other sites More sharing options...
Bill Posted March 23, 2009 Share Posted March 23, 2009 Here is a link to a drawing that shows the denticles in the 'wings' better. KOF, Bill. Welcome to the forum, all new members www.ukfossils check it out. Link to comment Share on other sites More sharing options...
PaleoRon Posted March 24, 2009 Author Share Posted March 24, 2009 Interesting links. I have found a few of those types of denticles and others that are similar. One of these days I'll accidently find the information I need while unsuccessfully looking for something else. Link to comment Share on other sites More sharing options...
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