cowsharks Posted January 17, 2012 Share Posted January 17, 2012 I've seen the large Otodus obliquus vertebrae from Morocco and even held some in my hand. They are huge and reach sizes of around 4" in diameter it seems. Well, for years now I've been collecting various Paleocene exposures in the Maryland and Virginia area and have never seen even so much as a partial large shark vertebra that might belong to Otodus. In fact, the largest shark verts I have found from these sites is around 1" in diameter. I have hundreds of Otodus teeth but no vertebrae. One long time collector of one of the Paleocene sites said he found an Otodus vert a couple decades ago and judging by the size he described it was at least a 2" or more in diameter. So, it begs the question, where are all the Otodus vertebrae? Did they just not fossilize well in these particular sediments? I know shark verts in general don't usually fossilize well, but I'm really disappointed that I haven't found one from the MD/VA area. I know many folks on this forum have collected some of the same Paleocene exposures, so I'm wondering if you have ever found any Otodus verts yourself, or heard of anyone else finding any? Daryl. Link to comment Share on other sites More sharing options...
Auspex Posted January 17, 2012 Share Posted January 17, 2012 My take on the conundrum: >Fossil shark verts are rare (ossified cartilage is fairly biodegradable, and comparatively fragile even if it does fossilize). >Great big sharks are rarer than small sharks. >The paleoenvironment in Morocco may have been quite different from that of the Mid-Atlantic coast; perhaps more suitable for great big sharks. >Larger sample size: the exposure of fossiliferous strata in the Moroccan phosphate-mining area is many orders of magnitude larger than those in MD/VA. "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...
cowsharks Posted January 17, 2012 Author Share Posted January 17, 2012 My take on the conundrum: >Fossil shark verts are rare (ossified cartilage is fairly biodegradable, and comparatively fragile even if it does fossilize). >Great big sharks are rarer than small sharks. >The paleoenvironment in Morocco may have been quite different from that of the Mid-Atlantic coast; perhaps more suitable for great big sharks. >Larger sample size: the exposure of fossiliferous strata in the Moroccan phosphate-mining area is many orders of magnitude larger than those in MD/VA. Roger that. I guess I'm just disappointed that I haven't even seen a piece of a large shark vert from the one site on the Potomac, and I've been there a couple hundred times or more in the last 16 years. Also, there's no way of knowing how many have been found by other collectors. I raised a similar question a few years ago on another Forum I believe in which the locale was Lee Creek. When I first started collecting back in 1996 I remembered hearing someone say that the Meg verts from Lee Creek were as big around as dinner plates. Well, in all those pics of Lee Creek finds on elasmo I don't recall ever seeing any Meg verts, let alone one that big. In all the years Lee Creek has been open to collecting you would think someone would have found one of those huge verts, even if they aren't as big as dinner plates. Daryl. Link to comment Share on other sites More sharing options...
Boneman007 Posted January 17, 2012 Share Posted January 17, 2012 (edited) http://www.ecphora.n...sil_museum.html Take a look at the meg verts on this site. They are of the 3" - 3.5" range. I also found one for sale that was 3 3/8" Heck, I have a 3.5" Leptostyrax shark vert from the Grayson formation of Texas. Wierdly, I have never found a Lepto in the Grayson. I expected these ol' boys to have monstrous verts. Edited January 18, 2012 by Boneman007 Link to comment Share on other sites More sharing options...
Northern Sharks Posted January 17, 2012 Share Posted January 17, 2012 What size are the majority of the Otodus teeth you're finding? Most of the ones I see for sale from the east coast are fairly small, while Moroccan ones are not that uncommon over 3". If there are a lot of larger teeth being found and kept in collections, I should mention I'd be in the market for one, but it seems to me that there aren't. The odds of finding a large vertebra in an area that doesn't produce many large teeth seems pretty remote. There's no limit to what you can accomplish when you're supposed to be doing something else Link to comment Share on other sites More sharing options...
Al Dente Posted January 18, 2012 Share Posted January 18, 2012 Daryl I have a couple hundred shark vertebrae from Lee Creek but only two or three are from lamnid sharks. One nice lamnid vertebra that I brought home fell to pieces when I put it in water. Lamnid vertebral centrums have a lot of radial septa and a lot of empty space that gets filled with sediment. The Yorktown Formation has a lot of clay that shrinks and swells as it dries and rehydrates. I believe that the delicate lamnid vertebral centrums break apart much more easily than other types of shark vertebrae. Link to comment Share on other sites More sharing options...
non-remanié Posted January 18, 2012 Share Posted January 18, 2012 (edited) Hard to make comparisons to one of the richest marine vertebrate deposits in the world, where bonebeds are said to be caused by mechanisms related to episodic mass die-offs, among other things. I would call it a Konzentrat-Lagerstätten although it seems like it has not been referred to in that way in the literature yet... Edited January 18, 2012 by non-remanié ---Wie Wasser schleift den Stein, wir steigen und fallen--- Link to comment Share on other sites More sharing options...
smokeriderdon Posted January 18, 2012 Share Posted January 18, 2012 I have found one fragment that may have been Otodus. If memory serves (and it may well be fuzzed here) a member of one of the local clubs found one. Thats all I can speak of there. Meg verts, I have seen 3 come out of Lee Creek in the 2.5 inch range. None in MY hands of course. LOL Link to comment Share on other sites More sharing options...
siteseer Posted January 18, 2012 Share Posted January 18, 2012 The larger Otodus teeth and vertebrae from Morocco tend to come out of the Early Eocene sites. The late Doug Donald, a dealer based in Silver Spring, MD, saw few large Otodus (anything over 1 1/2 inches perhaps) from the Early Eocene Nanjemoy Formation ("Muddy Creek" or other lesser-known sites) and I don't remember him ever mentioning a large vertebra from that. Shark vertebrae are fragile in any case (tough to prep). They are only partly ossified at best, and as Al Dente noted, some less than others. Hexanchid vertebrae have been reported as so poorly-ossified that they either faintly show up or they do not show up in an x-ray image. The most common seem to be the carcharhinid-type which look more solid internally when you examine a broken one. The vertebrae of larger lamniforms tend to be found in phosphate deposits or other deposits representing quiet environments with slow sedimentation. They cannot withstand much transport nor much compaction/compression. I've seen collectors who recognize the rarity of a big vert (anything over 2 inches) collect and keep even a ragged half of one. I've seen the large Otodus obliquus vertebrae from Morocco and even held some in my hand. They are huge and reach sizes of around 4" in diameter it seems. Well, for years now I've been collecting various Paleocene exposures in the Maryland and Virginia area and have never seen even so much as a partial large shark vertebra that might belong to Otodus. In fact, the largest shark verts I have found from these sites is around 1" in diameter. I have hundreds of Otodus teeth but no vertebrae. One long time collector of one of the Paleocene sites said he found an Otodus vert a couple decades ago and judging by the size he described it was at least a 2" or more in diameter. So, it begs the question, where are all the Otodus vertebrae? Did they just not fossilize well in these particular sediments? I know shark verts in general don't usually fossilize well, but I'm really disappointed that I haven't found one from the MD/VA area. I know many folks on this forum have collected some of the same Paleocene exposures, so I'm wondering if you have ever found any Otodus verts yourself, or heard of anyone else finding any? Daryl. Link to comment Share on other sites More sharing options...
Boesse Posted January 18, 2012 Share Posted January 18, 2012 Hey Folks, Figured the taphonomist in me better put in my two cents. Those above who have brought up the poor mineralization of shark vertebrae have brought up a very good point. Any preservation of cartilaginous elements is going to be dependent upon conditions of preservation - siteseer brought up phosphatization. The distinct impression I've gotten from reviewing the literature and from my own master's thesis research on marine vertebrate taphonomy suggests that phosphatization dramatically increases the preservation potential of cartilaginous skeletal material - to the point where phosphatized cartilaginous elements (vertebrae, complete phosphatized jaw cartilages) occur as shiny, black, dense elements with concreted phosphatic matrix on them. Whether or not the depositional environment is conducive to preserving vertebrae is going to be a major factor. There are many formations where there are abundant teeth. but no vertebrae, and some localities where there are very few vertebrae, but all sorts of other calcified elements (palatoquadrate and mandibular cartilages of skates). It also really depends upon how people are collecting them - if there is preservation of cartilaginous elements, but no early diagenetic mineralization (i.e. phosphatization), and people are pulling teeth out of river banks - then you're not really going to get much in the way of large vertebrae. I have a great shard of a huge (~6" wide) Cetorhinus maximus vertebra from the Purisima Formation, which you can see here. This specimen was in a (soft) phosphate nodule, which I prepared away with a microblaster. Bobby Link to comment Share on other sites More sharing options...
squali Posted January 18, 2012 Share Posted January 18, 2012 Great thread Thanks It's hard to remember why you drained the swamp when your surrounded by alligators. Link to comment Share on other sites More sharing options...
cowsharks Posted January 18, 2012 Author Share Posted January 18, 2012 Thanks for all the replies. I figured the underlying reason might be due to preservation in the particular sediments I'm hunting. It explains why the only shark verts I find from these particular sediments are the smaller more "solid" type that Siteseer referred to. Those don't have the fine septa that the Lamnids have, but instead just a couple of "holes" on each side. Daryl. Link to comment Share on other sites More sharing options...
PaleoRon Posted January 18, 2012 Share Posted January 18, 2012 There are a couple of reasons that large Otodus vertebra and teeth are scarce in the Paleocene deposits along the Potomac River in Maryland, but I do know of one complete Otodus vertebra that was found several years ago in a block that had fallen from the cliffs at Liverpool Point. It is over 3 inches across and more than an inch thick. It is very delicate and I have little doubt that the swelling of the clay matrix as it dried and a few strong waves would have destroyed it. I have found fragments of Otodus vertebra at the same location that would have been around two inches across if they were complete. My largest teeth from there are just over 2 3/4 inches. The large tooth with the pathological root was found in the same area as the vertebra and about three months prior. The slant lengths of these teeth are 2 3/4", 2 3/4", 2 1/2", and 2 1/2". Link to comment Share on other sites More sharing options...
cowsharks Posted January 18, 2012 Author Share Posted January 18, 2012 ...but I do know of one complete Otodus vertebra that was found several years ago in a block that had fallen from the cliffs .... Thanks Ron. Maybe it was the vert that I had heard about. Either way, it gives me hope that one day I'll find one myself! That huge Otodus is ridiculously huge for a MD tooth. As you well know they average more like 1-1.5", and of course, 95% of them are always damaged in some way. They must have eaten turtles with hard shells to cause so much damage. Thanks for posting those pics - I've never seen Otodus quite so big from MD. M. Hurd would be jealous if he saw those! Daryl. Link to comment Share on other sites More sharing options...
smokeriderdon Posted January 19, 2012 Share Posted January 19, 2012 Ron as in bird named after you Ron? Link to comment Share on other sites More sharing options...
siteseer Posted January 19, 2012 Share Posted January 19, 2012 I've never collected there but have friends who have hunted various sites many times. Those teeth are easily the largest Aquia Otodus I've seen (even bigger than the Nanjemoy tooth I have). Years ago, Don Malick sent me a tooth he collected. It's worn but still reaches 1 3/4 inches. I used to wonder how much bigger they could get. Thanks for the photos. There are a couple of reasons that large Otodus vertebra and teeth are scarce in the Paleocene deposits along the Potomac River in Maryland, but I do know of one complete Otodus vertebra that was found several years ago in a block that had fallen from the cliffs at Liverpool Point. It is over 3 inches across and more than an inch thick. It is very delicate and I have little doubt that the swelling of the clay matrix as it dried and a few strong waves would have destroyed it. I have found fragments of Otodus vertebra at the same location that would have been around two inches across if they were complete. My largest teeth from there are just over 2 3/4 inches. Link to comment Share on other sites More sharing options...
cowsharks Posted January 20, 2012 Author Share Posted January 20, 2012 There are a couple of reasons that large Otodus vertebra and teeth are scarce in the Paleocene deposits along the Potomac River in Maryland, but I do know of one complete Otodus vertebra that was found several years ago in a block that had fallen from the cliffs at Liverpool Point. It is over 3 inches across and more than an inch thick. It is very delicate and I have little doubt that the swelling of the clay matrix as it dried and a few strong waves would have destroyed it. I have found fragments of Otodus vertebra at the same location that would have been around two inches across if they were complete. My largest teeth from there are just over 2 3/4 inches. The large tooth with the pathological root was found in the same area as the vertebra and about three months prior. The slant lengths of these teeth are 2 3/4", 2 3/4", 2 1/2", and 2 1/2". Ron, did you find all of those large Otodus teeth or trade for them? Link to comment Share on other sites More sharing options...
earthdog Posted January 25, 2012 Share Posted January 25, 2012 I have found one fragment that may have been Otodus. If memory serves (and it may well be fuzzed here) a member of one of the local clubs found one. Thats all I can speak of there. Meg verts, I have seen 3 come out of Lee Creek in the 2.5 inch range. None in MY hands of course. LOL If the verts are in the 2.5 inch range, how were they identified as belonging to a megalodon ? I thought it was size alone that confirmed if a vertebrae was from megalodon as opposed to from another shark. I have a large vert from S.C, and was told it could only be Isurus Hastalis or Megalodon, because they were the only sharks with verts that large in that area, but since shark vertebrae look so similar, there was no way to tell for sure, unless the vertebrae is over 4.5". Link to comment Share on other sites More sharing options...
New Members raptor Posted February 23, 2012 New Members Share Posted February 23, 2012 Hi guys, interestingly enough, I have just acquired a large 4 foot section of vertebral column from an Otodus Shark, discovered in Kem Kem Morocco. Of course this is highly unusual and rare, bearing in mind the cartilaginous nature of the vertebrae. It just proves there are some amazing pieces out there. If you want to see them they are on www.finefossils.com, category "fish". I think they are outstanding. They just need a little more prep work to make them superb! Link to comment Share on other sites More sharing options...
Auspex Posted February 23, 2012 Share Posted February 23, 2012 That is fantastic! "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...
cfin1974 Posted February 25, 2012 Share Posted February 25, 2012 I find lots of cretaceous fish vertabrae and I dream of finding even a little shark one.. maybe someday Link to comment Share on other sites More sharing options...
gwbh Posted February 25, 2012 Share Posted February 25, 2012 here is my biggest shark vert, 1.7 inches. anyone have any idea of what kind? Link to comment Share on other sites More sharing options...
Paleoc Posted February 25, 2012 Share Posted February 25, 2012 Carcharhinid, the wear (and angle of the photo) on it makes id down to the species level difficult. Link to comment Share on other sites More sharing options...
gwbh Posted February 26, 2012 Share Posted February 26, 2012 what about now? Link to comment Share on other sites More sharing options...
Haizahnjager Posted December 15, 2012 Share Posted December 15, 2012 (edited) Roger that. I guess I'm just disappointed that I haven't even seen a piece of a large shark vert from the one site on the Potomac, and I've been there a couple hundred times or more in the last 16 years. Also, there's no way of knowing how many have been found by other collectors. Daryl, After reading your post merely one week ago, I headed to the Potomac for a paleocene outing, and wouldn't you know it -- I found an Otodus obliquus centrum! Prior to this find, I had not seen so much as a sliver of a large vert at this site. What remains measures a whopping 90mm (3.54") across by 31mm (1.22") thick! Measuring the radius from the most complete side of the vert (and assuming the more damaged side to be of similar size) would yield a diameter of 110mm (4.33")!!! I am now curious if anyone (possibly with associated Moroccan Otodus material) knows vert size to tooth size ratio? (I understand it would depend on the position of the centrum in the spinal column, but assuming this is the largest vert the shark had). In other words, how large would the teeth have been from this individual? Thanks for posing the original question, as I am sure many of us were curious. -HZJ Edited December 15, 2012 by Haizahnjager Link to comment Share on other sites More sharing options...
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