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Identification of Spinosaurid Jaws


Troodon

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Location: Morocco Kem Kem Beds

To often Crocodile jaws are composited with Spinosaurid teeth and sold as Spinosaurus jaws.  So the purpose of this topic is to show the diagnostic features of Spinosaurid jaws

 

First its extremely rare that any jaw from this region contains functional teeth.  Germ/unerupted teeth are more common but those are typically well into the tooth cavity and not protuding above the jaw line.  So its highly probable that those you see sold with teeth are composited.

 

We currently do not know if there is a variation between the jaws of the different Spinosaurids described or yet to be discovered in this region so there could be some difference between them but the general characteristics should be similar.  

 

Here is a composite skull in private hands and paleontologist Cristophe Hendrickx drawing of that skull

dscn6819.thumb.jpg.ab62e0b573eee52ea79bc3e8f2168094.jpg

spinoskullchimere.jpg.2c40c80565f3673319a8ceb243eec557.jpg

 

 

Dentary:

This is Stromers original plate.

1) You can see the variation in the lateral (side) view of jaw.   A very wide anterior end and more V shaped  toward the hinge.  So jaw sections that you see sold which are straight across are probably crocodile.

2) The teeth are also not positioned in a straight line, and not always next to one another.  

3) The most telling feature is the lip on the labial side.  It should be present across the entire length of the jaw

4) Broken dentary jaw sections being sold should wide not narrow like croc's

Screenshot_20170914-162058_20180424051526811.jpg.8a7d30c56a7c27cb880e7e66764b8f8a.jpg

 

Closeup of Lip SpinoJaw1_20180424053758931.jpg.2756fc1c793c4b53de7eff1fd6f7ed41.jpg 

Close up of germ/unerupted teeth

SpinoJaw1f.jpg.6c6c9f1a0fe7b04eb489cb3f888009e3.jpg

 

 

Premaxillary/Maxillary

 

Much more robust than dentary however the lip feature is still present but on the lingual side.  Very wide in lateral view.

 

journal_pone.0144695_g011.PNG.51da16f79cdb1bafddb67556a80e64a2.PNG

http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0144695

 

Spinosaurus_marocannus.thumb.jpg.409cc01bb291f6bb4d6b6b2adb13cb02.jpg

Spinosaurus_skull-Dal_Sasso_05_paper.thumb.png.cae1f2464b0a06cc423ab045813ef313.png

 dal Sasso, C.; Maganuco, S.; Buffetaut, E.; Mendez, M.A. (2005). New information on the skull of the enigmatic theropod Spinosaurus with remarks on its sizes and affinities. Journal of Vertebrate Paleontology. 25 (4): 888–896. doi:10.1671/0272-4634(2005)025[0888:NIOTSO]2.0.CO;2

 

Maxilla for sale with composite teeth

IMG_0440.thumb.JPG.d7f153e791de9999e96638f4a65f66ba.jpg.0bfd8849b1b1f001ba6c43af3045fa2e.jpg

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3 hours ago, Troodon said:

 

Dentary:

 

This is Stromers original plate.

1) You can see the variation in the lateral (side) view of jaw.   A very wide anterior end and more V shaped  toward the hinge.  So jaw sections that you see sold which are straight across are probably crocodile.

2) The teeth are also not positioned in a straight line, and not always next to one another.  

3) The most telling feature is the lip on the labial side.  It should be present across the entire length of the jaw

4) Broken dentary jaw sections being sold should wide not narrow like croc's

Though the relative thickness will likely be very similar, I would like to point out that there are definitely also younger Spinosaurids present that are less than half of adult size. So there is a possibility of coming across smaller jaw specimens.

 

2 hours ago, doushantuo said:

bcapt_inriyoreurt_011134x3473.jpg

Wow that's a really different reconstruction of the Angaturama snout on C. Normally it's reconstructed as being very square.

Olof Moleman AKA Lord Trilobite

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