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Theropod Teeth Morphology - Kem Kem Basin


Troodon

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@LordTrilobite  Find you comments interesting.  At the Tucson show I looked at hundreds of Spino teeth at all the different merchants and could not find any that fit a Baryonyx like crown.   All fit what I call the traditional tooth or those that were described in Richters paper on isolated teeth/

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Well I'm not saying we should expect teeth identical to the holotype of Spinosaurus aegyptiacus and the holotype of Baryonyx walkeri. but seeing as it's likely that Spinosaurus aegyptiacus or at least Spinosaurus sp. is present in Kem Kem and that Sigilmassasaurus appears to be inside Baryonychinae it could still be worth comparing to the other Spinosaurids as it would be logical that there would be some difference in dentition.

Olof Moleman AKA Lord Trilobite

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Excellent and highly informative posting my friend Frank!

 

I have deposited in my private collection this fossil tooth of  Theropod indet. from Kem Kem:

 

image.png.5a36651ee13c986b60789a2b8a1873be.png

 

image.png.455fad098d4e609cc4e9e2b9db830a76.png

 

image.png.2f114fbc8c5c65380f031cabeee47393.png

 

This tooth does not appear to be Carcharodontosaurid, the morphology also does not fit with dromaeosaurid, and in this new your post, unfortunately I could not identify any that were even similar to mine.  :(

 

For now, no hint at all?

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Is It real, or it's not real, that's the question!

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6 hours ago, Seguidora-de-Isis said:

Excellent and highly informative posting my friend Frank!

 

I have deposited in my private collection this fossil tooth of  Theropod indet. from Kem Kem:

 

This tooth does not appear to be Carcharodontosaurid, the morphology also does not fit with dromaeosaurid, and in this new your post, unfortunately I could not identify any that were even similar to mine.  :(

 

For now, no hint at all?

Thanks, it could be a large bodied Abelsaurid tooth.  One recent article that I read points to the possibly 3 Abelsaurids in this assemblage, two small bodied and one large.  The teeth are typically very compressed hard to determine with your photo's.  Denticles are typically rectangular like yours.  

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I feel this is worth mentioning in this post it is crucial to rememer that the kem kem is composed of 3 formations each spanning a few million years apart and for this reason I believe you see so much in terms of species and also to note the amount of fish and turtle remains You don't see on the common auction websites truly leads me to believe that not all of these species lived at the same time. Again more photographs to come of Morocco from my trip... when I return from Bristol.

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Yes but the typical Spinosaur related fauna is only found in two of those formations as far as I know. The Aoufous and Ifezouane formations.

 

But yeah it would be interesting to see some more studies on which animals lived in which layers. Maybe then we can see if there's any merit to the idea that Spinosaurinae replaced Baryonychinae as time went on.

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Olof Moleman AKA Lord Trilobite

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All good points the problem is are not yet able to distinguish a specific assemblage that characterises the Ifezouane Formation to the similar Aoufous Formation why they call it Kem Kem beds

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Tried to summarize some of Christophe Hendrickx and Octavio Mateus comparisons of the different families of theropod teeth to see how it compares to our different morphs types.

 

Abelsaurids : Display a slightly concave, straight or convex distal profile, mesial carina reaches the cervix, some denticles are hooked (Rugops & Majungasaurus) and the mesial teeth show a concave area adjacent to the mesial and, in some cases, the distal carina on the lingual surface of the crown

 

Noasaurids: Teeth are small (CH <15 mm), the lateral teeth have a mesial carina reaching the cervix, the distal denticles are hooked apically in some taxa (e.g., Masiakasaurus), and distal denticles are larger than mesial denticles

 

Dromaeosaurids: The lateral teeth of some lack a serrated mesial carina.  When present, the mesial carina of lateral teeth can be twisted, as in Dromaeosaurus.  The mesial denticles that are smaller than the distal ones. The distal denticles can also be hooked apically.

 

Carcharodontosaurids:

They are strongly compressed, as seen in the lateral dentition.  The mesial carina may not reach the cervix, the distal carina is slightly displaced labially, and they also have marginal and transverse undulations, interdenticular sulci, a braided enamel  texture.  The mesial teeth of carcharodontosaurids are similar to those of megalosaurids. The mesial carina faces mesially or can terminate well above 
the cervix as in the premaxillary teeth

 

Megalosauroids also share the above traits.

Mesial and distal denticles decrease in size towards the base of the crown and similarly towards the crown apex.

 

Spinosaurids:  The mesial and distal serrations are minute or absent, the mesial carina always reaches the cervix, the enamel texture is deeply veined (except in Irritator) and the crowns are subcircular in cross-section and sometimes fluted on one or both lingual and labial surfaces.  Richter study also describes one morph without fluting on both surfaces.

 

Mesial carina may not reach cervix:  

This trait is seen in non-spinosaurid megalosauroids and most piatnitzkysaurid mesial and lateral teeth, neovenatorids, carcharodontosaurids, megaraptorans, dromaeosaurids and microraptorans.

 

 

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2 hours ago, Troodon said:

Tried to summarize some of Christophe Hendrickx and Octavio Mateus comparisons of the different families of theropod teeth to see how it compares to our different morphs types.

 

Abelsaurids : Display a slightly concave, straight or convex distal profile, mesial carina reaches the cervix, some denticles are hooked (Rugops & Majungasaurus) and the mesial teeth show a concave area adjacent to the mesial and, in some cases, the distal carina on the lingual surface of the crown

 

Noasaurids: Teeth are small (CH <15 mm), the lateral teeth have a mesial carina reaching the cervix, the distal denticles are hooked apically in some taxa (e.g., Masiakasaurus), and distal denticles are larger than mesial denticles

 

Dromaeosaurids: The lateral teeth of some lack a serrated mesial carina.  When present, the mesial carina of lateral teeth can be twisted, as in Dromaeosaurus.  The mesial denticles that are smaller than the distal ones. The distal denticles can also be hooked apically.

 

Carcharodontosaurids:

They are strongly compressed, as seen in the lateral dentition.  The mesial carina may not reach the cervix, the distal carina is slightly displaced labially, and they also have marginal and transverse undulations, interdenticular sulci, a braided enamel  texture.  The mesial teeth of carcharodontosaurids are similar to those of megalosaurids. The mesial carina faces mesially or can terminate well above 
the cervix as in the premaxillary teeth

 

Megalosauroids also share the above traits.

Mesial and distal denticles decrease in size towards the base of the crown and similarly towards the crown apex.

 

Spinosaurids:  The mesial and distal serrations are minute or absent, the mesial carina always reaches the cervix, the enamel texture is deeply veined (except in Irritator) and the crowns are subcircular in cross-section and sometimes fluted on one or both lingual and labial surfaces.  Richter study also describes one morph without fluting on both surfaces.

 

Mesial carina may not reach cervix:  

This trait is seen in non-spinosaurid megalosauroids and most piatnitzkysaurid mesial and lateral teeth, neovenatorids, carcharodontosaurids, megaraptorans, dromaeosaurids and microraptorans.

 

 

 

Great summarization. The only thing I would slightly disagree with Hendrikx and Mateus would be in their description that, in dromaeosaur teeth, “When present, the mesial carina of lateral teeth can be twisted, as in Dromaeosaurus.” Saurornitholestine lateral teeth don’t have the mesial twist of the mesial carina as in Dromaeosaurus. They can be more centrally located on the anterior edge, or slightly mesially offset, without the noticeable twist seen in Dromaeosaurus. 

 

Thanks for the summarization Frank. Very useful.

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1 hour ago, hxmendoza said:

 

Great summarization. The only thing I would slightly disagree with Hendrikx and Mateus would be in their description that, in dromaeosaur teeth, “When present, the mesial carina of lateral teeth can be twisted, as in Dromaeosaurus.” Saurornitholestine lateral teeth don’t have the mesial twist of the mesial carina as in Dromaeosaurus. They can be more centrally located on the anterior edge, or slightly mesially offset, without the noticeable twist seen in Dromaeosaurus. 

 

Thanks for the summarization Frank. Very useful.

I think your reading to much into it .  They used Dromaeosaurus as an example of the twist "when present" and did not infer it was present in all Dromaeosaurids

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21 hours ago, Troodon said:

I think your reading to much into it .  They used Dromaeosaurus as an example of the twist "when present" and did not infer it was present in all Dromaeosaurids

 

You're probably right about that Frank. Just covering all the bases because I’m anal retentive.

:-)

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23 minutes ago, hxmendoza said:

 

You're probably right about that Frank. Just covering all the bases because I’m anal retentive.

:-)

ha ha but your are correct to be looking at all bases because it does not take much to have a very different view of things.  Thanks

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On 18/02/2018 at 9:59 AM, Troodon said:

Thanks, it could be a large bodied Abelsaurid tooth.  One recent article that I read points to the possibly 3 Abelsaurids in this assemblage, two small bodied and one large.  The teeth are typically very compressed hard to determine with your photo's.  Denticles are typically rectangular like yours.  

 

Thanks for the answer my friend @Troodon! Certainly it helped me a lot to be able to know that maybe this tooth belonged to a large Abelsaurid. I was just curious, what would this recent article be?

Is It real, or it's not real, that's the question!

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  • 6 months later...

Thought I'd add some photos of an unusual theropod indet. tooth (identified as such by Troodon a couple of years ago) in my collection, for reference in this thread.

 

Mesial serrations: 8/2mm (midline)

Distal serrations: 5/2mm (midline)

 

Mesial serrations end 3/4 of the way down the surface.

 

Labial side(?):

IMG_20190102_182211675.thumb.jpg.294182921c9c46d2502e7468f83ac3f7.jpg

 

Lingual side(?):

IMG_20190102_182100259_HDR.thumb.jpg.d51038b9d96ca418a533c633fffa2216.jpg

 

Distal view:

IMG_20190102_182425343.thumb.jpg.2f49cb67c4ead3e56b21ce8784e480d3.jpg

 

Mesial view:

IMG_20190102_182403277.thumb.jpg.15cfe7f6b3c624dec6b803098d52a33c.jpg

 

Cross section:

IMG_20190102_182546930.thumb.jpg.d39019405b8d0bd0ddf74de883505ad9.jpg

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  • 4 weeks later...

Sorry if I sound like a complete dunce, but I recently came across this concerning Australovenator:

 

5cd95e545d247_Picture7.png.dfc834b2d598e0ea7be8fa651f1d8d12.png

 

It's probably nothing, but the features identified here seem to be present on the theropod tooth I posted images of in the above post, including -

 

• Slightly asymmetrical & compressed cross section

• Transverse undulations

• Denticles on the mesial carina increasing in size from the base, then seemingly decreasing again towards the apex (wear makes this difficult to see)

• Decrease in size on the distal denticles towards the base; increase towards apex

• Midline distal denticle count = 12/5mm (within described range)

• Very slight labio-lingual depressions

• The same lingual deviation of the distal carina (minor on the above photo of mine, but does appear to be present)

 

Is it possible that Megaraptorans could be present in the Kem Kem?

 

 

A few clearer photos of the tooth to add to the existing shots:

 

IMG_20190513_133750073.thumb.jpg.ced6e5bd367813102da218ef8266d881.jpg5cd969b89654f_IMG_20190513_1337113562.thumb.jpg.e03d23362e5b6b6c5c52eeb896962c05.jpgIMG_20190513_133846366.thumb.jpg.fcc600bcff52fc046e17b259d9382de6.jpg

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25 minutes ago, Omnomosaurus said:

 

Is it possible that Megaraptorans could be present in the Kem Kem?

Good analysis and absolutely since we know so little about its theropods unfortunately there has been no published evidence of one.  We first need to understand what the characteristics are of the known taxons and see if this morphology fits one of them.  I think Deltadromeus is a candidate but we cannot exclude dinos that have yet to be discovered like a Megaraptor.

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  • 2 weeks later...

Hope you don't mind, Troodon, but I thought I'd add photos of my latest Theropod indet. tooth to this thread for reference, since it doesn't seem to match any of the currently known tooth morphologies.

 

IMG_20190522_202051310.thumb.jpg.5567027d4e34c94ad7bfddf26fa5e2c5.jpg

 

- Robust profile.

- Mesial carina extends 1/2 way down the mesial margin.

- Distal carina reaches cervix.

- No wrinkled enamel.

- No apparent interdental succuli.

 

Denticle count at midline (over 5mm):

Mesial: 13

Distal: 10

 

IMG_20190522_161435818.thumb.jpg.31e378ac9c96d66c2dc0e2922ece91c8.jpgIMG_20190522_161326350.thumb.jpg.f606a2cbe2f7154f9ea907eee96ffcd2.jpg

 

Mesial Margin:

IMG_20190522_161743261.thumb.jpg.9b8d16cd805fc9afa4ac40a8fd716974.jpg

 

Distal Margin:

IMG_20190522_161647520.thumb.jpg.2772bf841075b5728aabc5d14e11c682.jpg

 

Cross Section:IMG_20190522_104712455.thumb.jpg.307586df3211de8413d576f4894671d3.jpg

 

 

Denticle comparison (distal carina) with Carcharodontosaurid tooth of approx. same size:

 

Theropod indet                                 Carch. indet

5ce6a3e6f3fab_IMG_20190522_2050448526.thumb.jpg.6110ca2e828836d74194da985f4f5aef.jpg5ce6a3e6211f7_IMG_20190522_2050448527.thumb.jpg.fa94b21dc21e400c4a44eb2c95a2da6b.jpg

 

Serrations appear to be slightly smaller/thinner, with wider spacing between each denticle on close inspection.

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Great photos hopfully we can get some clarification on these different morphologies.  Just could be positional variations or normal differences between animals.

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4 minutes ago, Troodon said:

Great photos hopfully we can get some clarification on these different morphologies.  Just could be positional variations or normal differences between animals.

 

Could well be!

 

I think even one species being described in black and white at this point would go a long way to helping clear up the confusing mess that is the Kem Kem.

 

It's exciting that there's still so much left to discover there, but the mystery isn't doing us any favours! :ighappy:

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  • 1 year later...
On 13/02/2018 at 7:35 AM, Troodon said:

Morph Type 3

Dentary? Anterior

Mesial carina extends 3/4 crown height

Denticles parallel to the base and rounded at tip

Serration Density:

   Distal: 2.2/mm (More dense toward the base)

   Mesial: 2.4/mm (More dense toward the base)

 

5a821e2627550_Morph3.thumb.jpg.812053c6924ee21f399321f342c53ecf.jpg

 

Hi Frank, I may have an answer for this. Here's my tooth which is highly similar to yours.

 

Profile-1.thumb.jpg.e577b354dac5ba73188d4f63ff7a591b.jpgProfile-2.thumb.jpg.0274830425635e9925282ced73606b3d.jpg601bf918e5238_Mesialedge2.thumb.jpg.a96e6d5905417c6241c7738fd2dda1af.jpg601bf9165251b_Distaledge.thumb.jpg.587f4befbdb16441f39f07535fe36ea5.jpg601bf91b6259d_Perspective2.JPG.c142667f52a9820832979ae9a4faac5a.JPG601bf910ea934_Distaldenticlesclose-up.thumb.jpg.fb650dd5c28eb19cd7e62f0e65daa4b6.jpgSerration-count-on-mesial-mid-line.thumb.jpg.31aec466ded8a5004edc813ee7732d0c.jpg601bf90e32654_Crosssection.jpg.ee4c965640711f61c0d764e830c6ad57.jpg

 

This tooth has a Crown Height of 28.9 mm, Crown Basal Length of 12.32 mm and Crown Basal Width of 8.08 mm. Its denticles serration count is 11.5/5mm on the distal mid line and 13/5 mm on the mesial mid line. It's distal carina is slightly curved while its mesial carina ends 4/5 of the way.

 

Dr Ute Richer who co-wrote "Isolated theropod teeth from the Kem Kem Beds (Early Cenomanian) near Taouz, Morocco" told me this:

 

After comparison with photos of theropod teeth from Gondwana and with my own photos I come to the conclusion that your tooth is from a carcharodontosaurid theropod, probably a youngster, because the tooth crown has only a total length 3 cm. Which is really mall for a carcharodontosaurid. The tooth is relatively flat and bladelike and slightly recurved and there is no strong size difference between mesial and distal denticles. And it is usual in carcharodontosaurid teeth that the mesial denticulation does not run along the complete carina as the distal denticulation does and that the carinae have a slight dislocation from the midline (undulation).


And you are absolutely right that this pattern matches for tyrannosaurid teeth as well. I have recognized this state and a strong twist of the carinae away from the midline in tooth material from the Late Jurassic of Germany/Lower Saxony, which contained mostly teeth from small and larger tyrannosaurids. But tyrannosaurid theropods were not distributed in Gondwana, it is a typical Laurasian group.

 

In general the denticle shape is not such a strong pattern for the identification ot theropd teeth, because they have a high variation rate even between individuals. More robust patterns are the denticle count numbers and if there is a size difference between lateral and distal denticles, the location of the carinae (twisted, undulated or straight), the overall shape ot the distal carina (straight or curved) and the lateral compression of the crown (round or flat oval cross section).

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Looking forward to meeting my fellow Singaporean collectors! Do PM me if you are a Singaporean, or an overseas fossil-collector coming here for a holiday!

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22 hours ago, -Andy- said:

Hi Frank, I may have an answer for this. Here's my tooth which is highly similar to yours

Thanks Andy, that's super, nice analysis.  The teeth are very similar.   Anterior Carch would have one of my guesses but without any real documentation to support that its nice to see a theropod paleontologist make that call.  

 

Edit: 

Updated Photo Morph 3 and got C. Hendrickxx to also verify Carch assignment

 

 

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  • 2 months later...

Stromer 1915

translation mine:

 

All teeth are pointedly coniform,hardly to barely recurved,in cross-section almost circular, some are slightly elongatedly oval.*

Their roots are fairly long ,pretty straight and in their upper parts thicker than the crown.

Essentially ,the enamel is smooth,basally finely striated and finely wrinkled in such a way that that is only visible with a loupe.

In the front and back,where the enamel reaches further down than usual,there is almost always a sharp smooth side present.

the pulpal cavity of adult teeth is very thin,as is the enamel,      ***the sides are imprinted on the dentine core

 

*** this was semantically somewhat difficult,but I think Stromer meant that the morphology of the sides is mirrored in the dentine core

he makes a remark on taphonomy:

after a remark on the parts being disturbed,either by predators or local hydraulics there follows:

"because there's very little rounding of the parts,and thin and fragile parts are prefectly preserved,further transport is unlikely"

He then goes on to remark that possible slight deformation of skeletal parts might be due to salt /gypsum dissolution,rather than 

"tectonics"

 

* "nur wenige etwas langsoval",in the original.So some teeth show a slightly more elliptical crossection

 

 

 

Edited by doushantuo
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