Identification of Kem Kem Sauropod Teeth

[Anomotodon]

Found this very interesting tooth which I believe might be a posterior Brachiosaurid from Kem Kem. This tooth has a distinct axial twist, which is a morphology not described in the Holwerda et al., 2018 preprint. I've been reading more about this trait, and it seems that axial twist is a synapomorphy (shared derived trait) of Brachiosaurids, not basal titanosauriformes in general. Also, Brachiosaurids in Albian-Cenomanian are nothing new, at least in North America, e.g., Abydosaurus and Sonorasaurus.

 

From Mocho et al., 2017:

 

Quote

D'Emic (2012) proposed the presence of maxillary teeth twisted axially through an arc of 30–45° as synapomorphy of Brachiosauridae, being present in the basal titanosauriforms Giraffatitan and Abydosaurus, and in the basal macronarian Europasaurus.

Although...

Quote

If Europasaurus corresponds to a non-titanosauriform macronarian, this feature might be a synapomorphy of a more inclusive group within Camarasauromorpha, or a convergence with brachiosaurids.

 

Either way, seems that other than definite brachiosaurids only Europasaurus shares this trait.

 

Another trait, that is largely based on personal observations because I couldn't find it in the literature is lingual shift of the distal carina. You can compare it to my Jurassic brachiosaurid here.

 

Tooth in question:

 

Distal carina

 

 

Jurassic brachiosaurid for comparison (have not seen this in other basal titanosauriformes)

 

 

 

Some brachiosaurids from Cretaceous of Lebanon for comparison

 

 

These very similar teeth (esp. D-G) from Cenomanian (!!!) of France were also described as brachiosaurid. Note a similarly shifted distal carina in G.

 

 

 

Has anyone seen any Kem Kem teeth with a similar twist?

Edited January 18, 2022 by Anomotodon

[Troodon]

Wow a interesting find good observations.  Certainly has all the characteristics of a Brachiosaurid.  I dont see any  evidence that any have been reported from the Cenomanian of North Africa so it would be an outstanding discovery.  Another alternative is that it could be pathologic or positional.  Why don't you send images to Femke M. Holwerda the author of the most recent sauropod paper in the KK and gets his comments. 

 

[Anomotodon]

On 1/18/2022 at 6:03 AM, Troodon said:

Wow a interesting find good observations.  Certainly has all the characteristics of a Brachiosaurid.  I dont see any  evidence that any have been reported from the Cenomanian of North Africa so it would be an outstanding discovery.  Another alternative is that it could be pathologic or positional.  Why don't you send images to Femke M. Holwerda the author of the most recent sauropod paper in the KK and gets his comments. 

 

 

Thanks, have not heard back from her yet. I have a suspicion that this is just a posterior tooth from a more common morph that would represent anterior teeth of brachiosaurids, because they had less of an axial twist than posterior ones, as you can see in these Giraffatitan jaws. I have seen somewhat more robust titanosauriform-type teeth from Kem Kem that did not have much of a twist, but also had this odd offset distal carina, which is why I am wondering if it could be a diagnostic trait and those teeth could be anteriors from the same taxon (I actually have a few of those too but no pics at hand unfortunately).

Additionally, most of the comparative material described in literature for brachiosaurid teeth is Jurassic, while this clade lasted ~50 million years and their tooth morphology undoubtedly changed since then. Look at this Abydosaurus skull, which is a brachiosaurid from Albian of Cedar Mountain formation - its teeth are significantly more elongated and less twisted than those of Giraffatitan or Brachiosaurus, at least in the anterior positions that are figured. Churre et al., 2010 also mention that axial twist is absent in dentary teeth.

I have a suspicion that in Kem Kem there are actually at least two species of titanosauriforms, based on teeth alone: I - this brachiosaurid with more robust teeth that have 1) offset distal carina 2) axial twist on posterior teeth 3) relatively more convex lingual surface; II - a more derived titanosauriform, maybe a Lithostrotian, with symmetrical peg-shaped teeth that have more a flattened lingual surface, just like many of yours and those described in Holwerda et al., 2018 preprint.

 

b is Giraffatitan

 

more Giraffatitan

 

Abydosaurus

 

[Troodon]

No argument here on multiple Titanosauriforms, sure seems possible with what you've provided.   I hope you do receive a response back would be nice to see what she had to say.   KK still has lots of mysteries to uncover.

[Fullux]

The 8th picture looks a bit like karongasaurus teeth. I'm no expert on sauropods, but they just looked like that to me.

[Troodon]

@Fullux thanks, yes the middle one does has some resemblance to that 8th picture.  KK sauropod dentitions are poorly understood hopefully some articulated jaws with teeth will pop up to give us answers like Karongasaurus or even Malawisaurus with both of those being early Cretaceous sauropods.  No such luck in the Kem Kem.   Unfortunately that's even the case with most theropods from that region the lack of articulated skull elements with teeth.

 

[Josh_irving]

Just looking for a second opinion about some sauropod teeth that I am trying to identify. Also wondering what formation from the kem kem group these would likely come from.

 

Batch 1: Titanosaurid indet 

 

 

Batch 2: Rebbachisaurid indet (?nigersaurus sp., due to the two wear faces on the teeth????)

[Troodon]

7 hours ago, Josh_irving said:

from the kem kem group these would likely come from.

Without a specific locality of where it was found it's difficult to say, why most material is identified as KKG.   Typically a lot of material sold comes from the

Ifezouane Formation .

The top group are indeterminate Titanosaurids and the bottom ones are Rebbachisaurus garasbae which tend to have longitudinal ridges and smaller in diameter.  Both can have wear facets.  Nigersaurus is only described from the Republic of Niger.

 

 

[Josh_irving]

11 minutes ago, Troodon said:

Without a specific locality of where it was found it's difficult to say, why most material is identified as KKG.   Typically a lot of material sold comes from the

Ifezouane Formation .

The top group are indeterminate Titanosaurids and the bottom ones are Rebbachisaurus garasbae which tend to have longitudinal ridges and smaller in diameter.  Both can have wear facets.  Nigersaurus is only described from the Republic of Niger.

 

 

 Great. Thank you for your help.

 

[Josh_irving]

19 hours ago, Troodon said:

Without a specific locality of where it was found it's difficult to say, why most material is identified as KKG.   Typically a lot of material sold comes from the

Ifezouane Formation .

The top group are indeterminate Titanosaurids and the bottom ones are Rebbachisaurus garasbae which tend to have longitudinal ridges and smaller in diameter.  Both can have wear facets.  Nigersaurus is only described from the Republic of Niger.

 

 

 

would you agree that this also also a titanosaurid tooth, just heavily worn down?

 

[Troodon]

4 hours ago, Josh_irving said:

would you agree that this also also a titanosaurid tooth, just heavily worn down?

 

It looks like the tip of a titanosaurid tooth with a very nice wear facet