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Could this be a Megalosaurus caudal vertebra?


msantix

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Hi,

 

Was wondering if this is a caudal vertebra from Megalosaurus? it is from Oxfordshire, England which is consistent with where Megalosaurus remains have been found but i am not sure of what diagnostic features separate Megalosaurus fossils from other dinosaurs and if there are enough diagnostic features on the bone in question. It is 6.7cm in length (2.65 inch). Thanks.

 

megalosaurus-bucklandi.jpg

megalosaurus-bucklandi.jpg

megalosaurus-bucklandi.jpg

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Not a lot published on this dude but if you look at other large Meglosaurids you can do some comparative analysis and quickly draw some conclusions. Not even close....:shakehead:  Sellers should provide supporting documentation with their claims.

 

I was able to find photos of vertebrae from a Torvosaurus from BYU Geology studies paper 1991, vol 37

 

Caudals

 

Screenshot_20200221-041651.thumb.jpg.f09f9abee718df620104b16f9ef10040.jpgScreenshot_20200221-041716.thumb.jpg.f0b2adddfa407f3ff0c106f01dfb8203.jpg

 

Dorsals

 

Screenshot_20200221-043044.thumb.jpg.53aca86c53c3569f5e17c08d6927b99e.jpgScreenshot_20200221-043037.thumb.jpg.1d3a49ebcdc67ab4161eeb2d6e414b73.jpg

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16 minutes ago, Troodon said:

Not a lot published on this dude but if you look at other large Meglosaurids you can do some comparative analysis and quickly draw some conclusions. Not even close....:shakehead:  Sellers should provide supporting documentation with their claims.

 

I was able to find photos of vertebrae from a Torvosaurus from BYU Geology studies paper 1991, vol 37

 

Caudals

Screenshot_20200221-041651.thumb.jpg.f09f9abee718df620104b16f9ef10040.jpgScreenshot_20200221-041716.thumb.jpg.f0b2adddfa407f3ff0c106f01dfb8203.jpg

 

Dorsals

 

Screenshot_20200221-043044.thumb.jpg.53aca86c53c3569f5e17c08d6927b99e.jpg

Ahh that's a shame, i suppose fossils from that locality are generally marketed as 'Megalosaurus' to boost sales. Thanks for the pics, they certainly do look quite different from the fossil in question.

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31 minutes ago, msantix said:

Ahh that's a shame, i suppose fossils from that locality are generally marketed as 'Megalosaurus' to boost sales. Thanks for the pics, they certainly do look quite different from the fossil in question.

Megalosaurus bucklandii is extremely rare and most of the ones I’ve seen on the market are misidentified. It’s a shame that sellers do this for the extra money :shakehead:.

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Another Megalosaurus vert. Image taken from Benson, R.B. 2010: A description of Megalosaurus bucklandii (Dinosauria: Theropoda) from the Bathonian of the UK and the relationships of Middle Jurassic theropods. Zoological Journal of the Linnaean Society, 157, 882-935.).

0092522C-5C7F-4A74-A09A-847E972A27B1.png

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I have already discussed this with you in a very detailed email the reasons why it is a megalosaur vertebra and seemed satisfied with what we discussed. 

As discussed with you.. knowing something of the location at which it was found is paramount. Comparative anatomy against dinosaur bones not from the location it was found (I.e. North American dinosaur material) isn't going to be helpful especially when all the vertebrae shown by other contributors are dorsal vertebrae and the one you have is clearly not a dorsal vertebra  and would therefore have a different shape. 

as discussed knowing the location and formation/rock it came from will help narrow down the identification. 

I have already given you a very detailed email discussing why this is a theropod vertebra (shape and position/size of the foramen on the underside of the vertebra etc..) along with the knowledge that the only theropod genera recorded/known from this location is megalosaurus. 

These forum discussions again do not give the seller the benefit of reply and clearly indicate that we all "don't know what we are doing" and "must have called it that to get more sales" despite that fact that a reasoned email and discussion has already taken place with the buyer as to why this was described as such.. which does not seem to be indicated above. 

I am happy to resist the email I gave to you on here so that people are fully aware of the thinking behind the identification. 

 

 

 

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Definitely looks alot more plesiosaur than theropod to me, I would lean alot towards pliesosaurus cause of the shape and that it's alot more comparable to pliesosaur than it is to most theropods, even other megalosaurus vertebrae from the uk.

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3 hours ago, fossils-uk said:

I am happy to resist the email I gave to you on here so that people are fully aware of the thinking behind the identification. 

I think that is a great idea and could  be of much interest in the future IDs or discussions. It is only fair to you that we understand your thinking on this ID. 

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5 hours ago, fossils-uk said:

Comparative anatomy against dinosaur bones not from the location it was found (I.e. North American dinosaur material) isn't going to be helpful especially when all the vertebrae shown by other contributors are dorsal vertebrae and the one you have is clearly not a dorsal vertebra  and would therefore have a different shape. 

Respectively I disagree with you.   Torvosaurus and Meglosaurus are both large bodied Meglosaurids and thats because their skeletal structure is similar especially the post cranial structure and good enough for a comparative analysis.   The first set of photos I included are Caudal vertebrae. .. The comparison is not even close to make an argument against, not sure why you are now taking the position you are.   It was an honest mistake that everyone makes when it comes to identifying non common material.

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Looks very plesiosaurian to me too.  Theropod verts are generally very concave in side view.  Yes, even in the tail.  And I have never seen that foramen at the bottom in anything other than plesiosaurs. There should to be two of them, but maybe that varies by body position.  I would also love to see the reasoning behind the ID.  I believe Oxfordshire has beds that would produce both Meg and plesiosaurs.  

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  • 2 weeks later...

Only just saw this thread again and saw all the new replies.... thanks everyone! i am very confident the fossil in question is from a plesiosaur and doesn't resemble theropod. I appreciate all the help!

 

 

On 25/02/2020 at 1:30 AM, fossils-uk said:

I have already discussed this with you in a very detailed email the reasons why it is a megalosaur vertebra and seemed satisfied with what we discussed. 

As discussed with you.. knowing something of the location at which it was found is paramount. Comparative anatomy against dinosaur bones not from the location it was found (I.e. North American dinosaur material) isn't going to be helpful especially when all the vertebrae shown by other contributors are dorsal vertebrae and the one you have is clearly not a dorsal vertebra  and would therefore have a different shape. 

as discussed knowing the location and formation/rock it came from will help narrow down the identification. 

I have already given you a very detailed email discussing why this is a theropod vertebra (shape and position/size of the foramen on the underside of the vertebra etc..) along with the knowledge that the only theropod genera recorded/known from this location is megalosaurus. 

These forum discussions again do not give the seller the benefit of reply and clearly indicate that we all "don't know what we are doing" and "must have called it that to get more sales" despite that fact that a reasoned email and discussion has already taken place with the buyer as to why this was described as such.. which does not seem to be indicated above. 

I am happy to resist the email I gave to you on here so that people are fully aware of the thinking behind the identification. 

 

 

 

Sorry are you referring to me? because i have never had a discussion with you or spoken to you before. I am not sure what your post is referencing.

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Here is a dinosaur vertebra from the Wessex formation to compare with the said offending vertebrae. 
the location does yield plesiosaur vertebrae from colymbosauurs (kimmerosaurus) but these have a totally different morphological shape. this is why the subject vertebra stood out when found. You can see from the histology that it’s dinosaurian not plesiosaurian. 
Hope this helps.

51AA3957-906D-4D03-A9E8-4850E10D4D8E.jpeg

5D185E10-DB17-4EA3-90E0-567305887BEF.jpeg

DD072945-EDD9-4FB1-80B9-D78D4C090608.jpeg

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