Identification of Kem Kem Sauropod Teeth

[Troodon]

Most everything you see sold on the commercial market as far as Sauropod teeth, from the Kem Kem of Morocco, is label Rebbachisaurus garasbae or Rebbachisaurus.   They appear to be incorrectly identified based on the latest research.  Feel free to add your teeth to show variations.

 

What do we know of Sauropod teeth from this fauna? - very simple answer, very very little in fact less than we know of Theropod material which is very little to begin with.  

 

In the Kem Kem there is one described species a Diplodocoid, Rebbachisaurus garasbae and evidence of a large Titanosaurid.   That evidence on the Titanosaurid is based only on a single caudal vertebra.   The holotype that described Rebbachisaurus contained only one complete dorsal vertebra, parts of another vertebra, some neural spines, rib fragments, ischium, humerus and a few more fragmentary material but NO skull, NO teeth.  Like many Theropod dinosaurs we have teeth but no skull to identify them against and label them to a family level.  Why should we not do the same with sauropod teeth there is no difference.  The other fact that I find interesting is Rebbachisaurus once thought to be a large bodied Sauropod has been redescribed to a smaller animal and the Titanoaurid from this fauna is a very large one.

 

EDIT:

The publication issued in 2018 sheds a new light on this topic.   The information here is based on that publication

https://peerj.com/articles/5925/

 

 

 

Rebbachisaurid indet

Faceted small diameter, smooth surface

 

 

This tooth is faceted all around the crown.

  

 

 

Very round, small diameter

 

 

This tooth includes a base with enamel on it - uncertain of placement

 

 

Titanosaurid indet

Large Teeth

 

 

Two very crisp cutting edges and very rough texture in the enamel, no wear facet maybe sign its an unerupted tooth.  Have not see the texture on any other tooth.

 

 

Very pointed Crown - positional?  No cutting edges

 

 

 

This tooth shows wrinkles around the shaft.  No its not a Spino no cutting edges

 

 

Felt sorry or these two orphans just added them to the mix.  Positional, no cutting edges

 

 

More peg like, no cutting edges, not sure about this tooth - My guess its Rebbachisaurid

 

 

 

[LordTrilobite]

Good stuff. I'll need to check which catagory my Sauropod tooth falls in.

[Tidgy's Dad]

I have seen lots of these teeth and am certain that there are at least two types of sauropod in the Kem Kem, I personally believe there are several. 

We just need to find the bigger bones and skulls. 

[Miocene_Mason]

Interesting, I think there are an incredible amount of undescribed sauropods in the Kem Kem. Hope we get more work done on these in the near future.

[Troodon]

The Jaws of Sauropods are very complex for example, Diplodocus in addition to its functioning row has 4 rows of replacement teeth and Titanoisaurids one fewer.  So some of the variation is expected however most of the teeth I show here appear to be from the functioning row due to the wear facet.  

 

Evolution of High Tooth Replacement Rates in Sauropod Dinosaurs

Michael D. D’Emic, John A. Whitlock, Kathlyn M. Smith, Daniel C. Fisher, Jeffrey A. Wilson Published: July 17, 2013

https://doi.org/10.1371/journal.pone.0069235

 

 

If we look at other assemblages we can see what is possible.  

 

The early Cretaceous of the Kirkwood Formation of South Africa is known for its high diversity of Sauropods and is currently represented by four different groups Diplodocoidea, Dicraerosauridae, Brachiosauridae and Eusauropod.  Unfortunately only postcranial material.  The fossil record later in the Cretaceous is pretty slim especially in South America where a lot of comparisons are made since the faunas a closely related..   Unfortunately most discoveries are headless 

 

From Japan 

Found this interesting paper Titanosauriform Teeth from the Cretaceous of Japan.  Some similarities to what is being sold as Rebbachisaurus 

  

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652011000100014

 

 

 

From Niger my smoking gun that we may have it wrong...or just don't know.

Nigersaurus is a Rebbachisaurid with very different teeth more peg shaped and small.  Scale bar for teeth 5 mm.   Clear evidence that Rebbachisaurids teeth can be peg shaped, small and very different and do not have to look like Diplo teeth..   So without a Rebbachisaurus skull we are clueless what it's teeth look like we may have it right or not.  

 

http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0001230

 

[hxmendoza]

Excellent post Troodon. Thank you!

Great photos too. What are you using to take these?

[Troodon]

On 12/25/2017 at 8:36 AM, hxmendoza said:

Excellent post Troodon. Thank you!

Great photos too. What are you using to take these?

Thanks.  I use a Canon  Rebel SLR digital with a macro lens, then Adobe photoshop elements

[Sagebrush Steve]

On 12/25/2017 at 8:44 AM, Troodon said:

Thanks.  I use a Canon  Rebel 35mm with a macro lens, then Adobe photoshop elements

You mean a 35mm film camera?  Or a digital SLR?

[Troodon]

16 minutes ago, Sagebrush Steve said:

You mean a 35mm film camera?  Or a digital SLR?

Oh correct must have been dreaming or senior moment. Who has film nowadays, thanks

[JohnBrewer]

18 hours ago, Troodon said:

Who has film nowaday

Ahem....

[Sagebrush Steve]

18 hours ago, Troodon said:

Oh correct must have been dreaming or senior moment. Who has film nowadays, thanks

 

53 minutes ago, JohnBrewer said:

Ahem....

Sheet film, no less, or do you still use glass plates?

[JohnBrewer]

2 minutes ago, Sagebrush Steve said:

Sheet film, no less, or do you still use glass plates?

Both. I prefer making my glass plates from scratch as they’re sooo much cheaper per shot than film. Large and ultra large format film is silly prices. 

 

[Troodon]

1 hour ago, JohnBrewer said:

Ahem....

Okay my bad, I'm talking about us amateurs.  

[JohnBrewer]

[zekky]

My contribution. Smaller tooth 1/2", very Nigersaurus like. 

 

 

[zekky]

Not sure I'm on the Diplodocidae train. Look at Nemegtosaurus, they look a bit like the Diplodocidae. Are we sure there's a Diplodocidae and not just a few different families of Titanosaurs? 

[zekky]

Here is Sarmientosaurus. Almost the same time as Kem Kem but in South America. Also the best known skull of a titanosaur. I believe the bulkier, slightly curved and textured teeth are possibly titanosaur. 

http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0151661

[Troodon]

29 minutes ago, zekky said:

Not sure I'm on the Diplodocidae train. Look at Nemegtosaurus, they look a bit like the Diplodocidae. Are we sure there's a Diplodocidae and not just a few different families of Titanosaurs? 

 

 

Well the paper that describes Rebbachisaurus calls it a Diplo. so that is all we have to go on.   They obviously felt that the holotype material, limited as it was,  was diagnostic enough to describe it as such.  But I agree with you that it might not be and with new discoveries, it could change.  One thing that my limited research as told me and your Nemegtosaurs images continues to confirm is that the shape of the tooth is not diagnostic to determining if its a Diplo or Titanosaurid.  Just think how small, tiny,  the sampling size is of what has been published.  We have a long way to go in understanding what is going on here, again why we are far from identifying teeth from the Kem Kem.

 

Have not seen any teeth similiar to those of Sarmientosaurus not to say they do not exist.   With the age being identical to the Kem Kem's it's very possible that variations are around.   Thanks for you input.

[Troodon]

Stumbled across this tooth which contines to support my case that identification of isolated sauropod teeth from the Kem Kem is still a mystery 

A late cretaceous Titanosauria from Madagascar whose teeth look remarkably like the Diplodocoid Rebbachisaurus  

 

[TyBoy]

Very informative for Kem Kem collectors 

Came across this just released preprint paper that supports Troodon's hypotheses that the sauropod teeth currently sold by everyone as Rebbachisaurus are improperly identified.  It describes two Morph types from Titanosaurids and Rebbachisaurids.  It does not assign them to a specific species since it's uncertain what species from each family are present.

 

 

https://peerj.com/preprints/27286/

 

Morph type I shows affinities to Titanosauriforms.

Features:

Rugose enamel wrinkling

Prounced carinae

Cross section : Lemon shaped to cylindrical

 

 

Morph Type II shows affinities with Rebacchisaurids

Features:

Smooth enamel

Cross Section : Cylindrical

 

[LordTrilobite]

4 hours ago, TyBoy said:

Very informative for Kem Kem collectors 

Came across this just released preprint paper that supports Troodon's hypotheses that the sauropod teeth currently sold by everyone has Rebbachisaurus are improperly identified.  It describes two Morph types from Titanosaurids and Rebbachisaurids.  It does not assign them to a specific species since it's uncertain what species from each family are present.

Great find! Definitely very useful.

 

 

Seems my Sauropod tooth from Kem Kem can keep it's Rebbachisaurid id with it's smooth enamel.

[Troodon]

Everything that is currently sold as Rebbachisaurus is currently improperly identified based on the publication that TyBoy posted.   All those teeth are Titanosaurid, smaller typically faceted teeth are asscoatied with Rebbachisaurid.   I have update my photos on the first page of this topic so that everyone can have a good look at them.

 

This chart from that paper shows that Morph I, Titanosaurid and Morph II Rebachisaurid.

 

 

[FossilDAWG]

Troodon!  Welcome back!  (Sorry if you've been back for a while but this is the first time I've seen you post in a long time).

 

Don

[-Andy-]

 

Just slightly related to this topic but I thought 'Open Nomenclature in the biodiversity era' was an interesting read. Frank, we talked about this 3 years ago in which we wondered if it would be possible to assign a species name when we haven't yet identified the actual species of Kem Kem Beds dinosaurs. As it turns out, assigning sp. 1 or sp. 2 to a genus name appears to be a valid form of naming.

[Troodon]

2 minutes ago, -Andy- said:

 

 

Just slightly related to this topic but I thought 'Open Nomenclature in the biodiversity era' was an interesting read. Frank, we talked about this 3 years ago in which we wondered if it would be possible to assign a species name when we haven't yet identified the actual species of Kem Kem Beds dinosaurs. As it turns out, assigning sp. 1 or sp. 2 to a genus name appears to be a valid form of naming.

Yes they did that with Spinosaurus 1 but never realized it was an accepted convention, thanks