Kem Kem Theropod Teeth: what you need to know

[Troodon]

I attended the official unveiling of Rugops Primus,a few years back as a guest of Paul Sereno and the teeth many people are describing as delta teeth are in fact more than probably the scavenger Rugops,I spoke at length with Gabrielle Lyon the discoverer and she described lots of these small teeth around the fossil remains,there was NO skull found,which is a great pity,these smaller teeth misidentified as delta are identical to the teeth i saw in the partial skull and jaws of Rugops primus,Thelarger teeth which are approx 2 inches narrow and long and laterally compressed,they are not in my opinion carch teeth and they were desribed to me by Gabrielle as been as been Delta more than probable,there is not other described large predator I know of that they could be from. .I have some photos which i can post once I get a hang of the forum

I would like to agree George's comments with support of a technical paper. We all recognize the small Abelisaurid teeth being sold as numerous different species (Post 90). However in 2005 papers were written indicating the presence of large bodied Abelsaurid's both in the Kem Kem and Maastrichtian Ouled Abdoun basin.

Large Bodied Abelsaurid Kem Kem: what is very informative in this paper is that it clearly states that the morphology of these teeth is very similar to Rugops primus out of Niger. Since these type of teeth have not been described we cannot call these teeth R. primus but I think it's fair to identify them as "cf Rugops primus" or Abelisaurid indet. How to identify is the question. The serrations at 2.3-3/mm are finer that a Carcharodontosaurid which are 2. Like George indicated they are approx 2" or less, narrow and laterally compressed. I think shape the serration is the key in properly identifying this morphology. I originally thought that these were cf Deltadromeus type but now leaning strongly to cf Rugops.

Abelsaurid Moroco.pdf

Carcharodontosaurid serrations

Large Bodied Abelsaurid?

Maastrichtian Abelisaurid

Paper and one recently acquired it's 6cm long

Thero Mor.pdf

[Dracorex_hogwartsia]

Troodon, the tooth in the picture is yours? You also own another tooth from the phosphate mines don't you? This tooth is absolutely stunning! About as perfect as you can get. I'm afraid as usual when it comes to this topic, the tooth in this paper and the tooth in the picture look like Carcharodontosaurus to me. I think if you were to show this tooth to almost any dinosaur tooth collector, carch not abelisaurid is what they would say. It definitely doesn't look like a Majungasaurus tooth, at least not to me.

Edited July 2, 2016 by Dracorex_hogwartsia

[Troodon]

Yes the tooth in the picture is my tooth and I also have a fully rooted one.

Yes these teeth can be easily be confused with Carch teeth but you need to know the locality of where it's from before making that call. Carch's are not found in Maastrichtian deposits where Abelisaurid's are. Also like I've said in many other posts it's all about the serrations and they are different has seen in my previous post. Of course new discoveries can change everything.

[doushantuo]

maybe nothing new here,but ,hey....

https://peerj.com/articles/1754.pdf

https://www.researchgate.net/publication/257787547_Isolated_theropod_teeth_from_the_Kem_Kem_Beds_Early_Cenomanian_near_Taouz_Morocco

Edited July 2, 2016 by doushantuo

[doushantuo]

or:

https://www.researchgate.net/publication/296295426_A_large_abelisaurid_Dinosauria_Theropoda_from_Morocco_and_comments_on_the_Cenomanian_theropods_from_North_Africa

https://www.researchgate.net/profile/Oliver_Rauhut/publication/235907596_Small_theropods_(Dinosauria_Saurischia)_from_the_Upper_Jurassic_and_Lower_Cretaceous_of_the_Iberian_Peninsula/links/0912f51404536d89e3000000.pdf

Edited July 2, 2016 by doushantuo

[doushantuo]

http://rspb.royalsocietypublishing.org/content/royprsb/277/1679/183.full.pdf

[doushantuo]

https://www.researchgate.net/publication/263127943_Integrating_palaeoecology_and_morphology_in_theropod_diversity_estimation_A_case_from_the_Aptian-Albian_of_Tunisia

[Troodon]

Thank you doushantuo for the pdf posts.

Let me offer you a suggestion that may help readers get the most out of these posts and PDF's. First when you post a PDF specifically describe what's in it so that members can make a determination to open it or not. Not everyone may be interested in that paper or they may not be on a desktop and opening one on a phone or tablet may become an issue for large files. It also provides the reader a easy way to refer back to it versus having to search multiple papers. Second every reader is at a different level of knowledge so it would be helpful to summarize the key points of that paper has it is revelant to the topic at hand. Finally papers that are not revelant to the topic should not be posted but can be started in another topic. There is a lot of information out there we just need to manage it to get the best use from it.

[Dracorex_hogwartsia]

Yes the tooth in the picture is my tooth and I also have a fully rooted one.

Yes these teeth can be easily be confused with Carch teeth but you need to know the locality of where it's from before making that call. Carch's are not found in Maastrichtian deposits where Abelisaurid's are. Also like I've said in many other posts it's all about the serrations and they are different has seen in my previous post. Of course new discoveries can change everything.

I read the paper again on this tooth. I see the height of the crown is 37mm. I didn't pay attention to that before. Smaller than I thought from the picture. What is the size of the crowns on your teeth? The author states that this tooth resembles teeth of "some" abelisaurids. I don't see that from the paper but you have the actual teeth. Do you agree with this? You've shown pictures in past posts of the different teeth from Morocco and your pictures of abelisaurid teeth don't look like this tooth to me but they do look like Majungasaurus. I noticed the author is using the junior synonym of Majungatholus in his paper.

[Troodon]

Lets not get these teeth confused, from the Cenomanian (Kem Kem beds) we have two teeth that resemble the morphology of Abelisaurid's one from a small and the other from a large bodied dinosaur. From the papers the large bodied one resembles the Rugops from Niger.

From Maastrichtian deposits we find another Abelisaurid that one paper says it resembles Majungatholus from Madagascar also an Abelisaurid. I would expect some similarities given the age and proximity. Will have to wait until it's described to properly assign it to a family. I'm not the expert. My two teeth have crowns around 4.5 cm.

[Dracorex_hogwartsia]

The author states that one of the reasons he is assigning this tooth to the abelisauridae is it's resemblance to this type of tooth. I was just stating that in my opinion, the teeth you describe as abelisaurid from the Kem Kem and Majungasaurus teeth from Madagascar look very similar to me. Both of these teeth are clearly abelisaurid. The tooth in the paper does not look like these teeth to me. You are extremely fortunate to have two examples of this rare tooth. When you compare them to your Kem Kem teeth and to your Majungasaurus teeth do you say to yourself, yep these are without a doubt abelisaurid teeth or do you say no, they actually look like something else?

[Troodon]

I'm not doing any comparison. I've just labeled them has Abelisaurid since the morphology resembles that family. Hopefully one day they get described.

[Dracorex_hogwartsia]

Ok, thanks. I respect your opinion on dinosaur teeth way more than I do professional paleontologists.

[doushantuo]

review of ALL spinosaurid material:

http://www.palarch.nl/wp-content/bertin_tor_2010_catalogue_and_review_of_spinosauridae_pjvp_7_4.pdf

review of the vertebrates of the Cretaceous of Morocco:

https://www.researchgate.net/publication/223833925_Vertebrate_assemblages_from_the_early_Late_Cretaceous_of_southeastern_Morocco_An_overview

Theropods from the Cretac.of Morocco(Geol Mag.,2009):

https://www.researchgate.net/publication/248687117_Theropod_teeth_from_the_basalmost_Cretaceous_of_Anoual_Morocco_and_their_palaeobiogeographical_significance

D.A.Russell on the Cretaceous(Tafilalt) dinosaur material of Morocco(large file,106Mb):

http://bibliotheques.mnhn.fr/EXPLOITATION/infodoc/ged/viewportalpublished.ashx?eid=IFD_FICJOINT_BMCTE_S004_1996_T018_N002_1

Kem Kem,Pal Zeitschr.2012:

Let's see:

Isolated rootless theropod teeth from the location under discussion in this thread are subjected to discriminant and canonical variate analysis.

morphologies:

carcharodontosaurid

spinosaurid

dromaeosaurid

Enamel ornamentation structures are discussed

Richterkemkempalzeitscmorocretac2012.pdf

Edited July 4, 2016 by doushantuo

[doushantuo]

would anyone be interested in:

"BETWEEN TENDAGURU AND BAHARIYA: ON THE AGE OF THE EARLY CRETACEOUS DINOSAUR SITES FROM THE CONTINENTAL INTERCALAIRE AND OTHER AFRICAN FORMATIONS"?

[Troodon]

Ok, thanks. I respect your opinion on dinosaur teeth way more than I do professional paleontologists.

Thanks but a bit overstated, I'm a collector just passing information on that paleontologists have developed.

Not sure if you've seen this paper of theropod teeth from Madagascar. If you look at figure 6 (A1 & A2) they illustrate a Majungatholus tooth which is very similiar to those in the Maastrichtian of Morocco. You could see why on the Moroccan paper they could draw the conclusion they did. Hopefully some day all of the Abelsaurid of the late cretaceous in Morocco will be described.

0c960519b5d6a87ddd000000-1.pdf

Edited July 4, 2016 by Troodon

[Dracorex_hogwartsia]

Thanks but a bit overstated, I'm a collector just passing information on that paleontologists have developed.

Not sure if you've seen this paper of theropod teeth from Madagascar. If you look at figure 6 (A1 & A2) they illustrate a Majungatholus tooth which is very similiar to those in the Maastrichtian of Morocco. You could see why on the Moroccan paper they could draw the conclusion they did. Hopefully some day all of the Abelsaurid of the late cretaceous in Morocco will be described.

0c960519b5d6a87ddd000000-1.pdf

Maybe I should restate that, "some" professional paleontologists :-) Your collection rivals many museums and most paleontologists are not necessarily experts on teeth. I think it was Thomas Carr that said in the past that he hates dealing with dinosaur teeth when it comes to identifying dinosaur species. I'll take a look at this paper. I definitely appreciate all that you do to contribute to this forum.

[Troodon]

I've talked to a number of noted paleontologist and a few have a real problem identifying isolated dinosaur teeth to a species level. Most want to deal with concrete facts, teeth tied to associated elements to draw conclusions, otherwise it can come back to bite them. I fully appreciate that issue and that's okay it's the nature of science. It's the collector that forces identification so they can feel rewarded by their find or purchase.

[JohnBrewer]

This thread is EXACTLY what Ive been looking for and I can see it's been useful to a lot of people. Great discussion, images and papers. Should be pinned IMHO

[CraigHyatt]

"I've talked to a number of noted paleontologist and a few have a real problem identifying isolated dinosaur teeth to a species level. Most want to deal with concrete facts, teeth tied to associated elements to draw conclusions, otherwise it can come back to bite them."

"come back to bite them"

har har har

[Troodon]

The one thing about Kem kem that bugs me, is, where are the herbivore teeth/fossils?

Finding what's been published is the biggest challenge to learning about dinosaurs and understanding what's written is the other. Attached is a paper published in 2013 that addresses your question.

Background: The Kem Kem Beds is a name that describes a region in Morocco that consists of 3 formations: Akrabou which overlies the Aoufous and the Ifezouane Formation is the oldest and contains the richest assemblage of dinosaur fossils and was used in the study.

The paper concludes the imbalances is related neither to non-systematic collecting, nor to stratigraphic biases. It states the palaeoenvironment seems to be the only likely factor to explain the significantly high proportion of carnivorous versus plant-eating dinosaurs. Conditions were unfavorable in developing stable terrestrial vegetation but favored aquatic life. This aquatic life formed the basic level of an aquatic or semi-aquatic food web, which directly fed top predators, such as theropods in general and spinosaurids in particular. It of course indicated that further investigation is necessary to address some areas.

So what we had in this region was a semi-aquatic environment that did not encourage the development of fauna that encouraged large herds of herbivores that we see in the late cretaceous of North America. If the study proves accurate looks like those herbivores were limited you a few sauropods. Sorry tooth collectors.

Unbalanced food web in a Late Cretaceous dinosaur assemblage by Emilie Läng et al, 2013

10.1016@j.palaeo.2013.04.011.pdf

Edited August 1, 2016 by Troodon

[zekky]

I have also noticed, that Iguanodonts may not have shed their teeth as much as other ornithopods. I know this is true of the Morrison Formation. Now I know that's a long time difference but I do wonder...

[Raptor Lover]

Finding what's been published is the biggest challenge to learning about dinosaurs and understanding what's written is the other. Attached is a paper published in 2013 that addresses your question.

Background: The Kem Kem Beds is a name that describes a region in Morocco that comprises 3 formations: Akrabou which overlies the Aoufous and the Ifezouane Formation is the oldest and contains the richest assemblage of dinosaur fossils and was used in the study.

The paper concludes the imbalances is related neither to non-systematic collecting, nor to stratigraphic biases. It states the palaeoenvironment seems to be the only likely factor to explain the significantly high proportion of carnivorous versus plant-eating dinosaurs. Conditions were unfavorable in developing stable terrestrial vegetation but favored aquatic life. This aquatic life formed the basic level of an aquatic or semi-aquatic food web, which directly fed top predators, such as theropods in general and spinosaurids in particular. It of course indicated that further investigation is necessary to address some areas.

So what we had in this region was a semi-aquatic environment that did not encourage the development of fauna that encouraged large herds of herbivores that we see in the late cretaceous of North America. If the study proves accurate looks like those herbivores were limited you a few sauropods. Sorry tooth collectors.

Unbalanced food web in a Late Cretaceous dinosaur assemblage by Emilie Läng et al, 2013

10.1016@j.palaeo.2013.04.011.pdf

Ahh makes a lot of sense!

[Susan from PA]

This is great information, Troodon! Thanks so much for sharing, even if it means I have less teeth to collect. .

[JohnBrewer]

I'm starting to go through my 'box o' bones' from Kem Kem and there are a couple of hundred teeth. In order for me to start trying to identify them is there a reliable list or could someone give me a list of known proven genera of airborne, land and marine reptilia and dinosaurs so I can start researching?