Moroccan theropod dinosaur tooth and other fossil ID help

[fossil_lover_2277]

Hi all! Soooo I just recently made a trip to my local mall, and the upscale mineral/fossil shop there had a bowl of assorted cheap Moroccan fossils for sale. As far as I could tell they were of Cretaceous marine origin, most of them being goblin shark and Cretolamna teeth. However there were a few interesting finds, including a small theropod dinosaur tooth!!! You bet I paid my $0.50 for that sucker =p Also, I found some sort of jaw bone, an unknown shark tooth (pathological?), and a possible fish skull cap maybe? I’m going to post them to the Fossil ID page for some help, I don’t know my Moroccan fossils lol

 

 

  

  

  

  

  

  

[Castle Rock]

BRAVO!!

[fossil_lover_2277]

3 minutes ago, Castle Rock said:

BRAVO!!

Thank you!!!!!

[Runner64]

Have a cross section photo of the theropod tooth?

 

Are there serrations on it?

Edited August 31, 2021 by Runner64

[fossil_lover_2277]

8 hours ago, Runner64 said:

Have a cross section photo of the theropod tooth?

 

Are there serrations on it?

Yea here’s some pics of the underside

 

Also it has two cutting edges, if it has serrations I can’t see them without a microscope, they’re small.

I know crocs generally don’t have two cutting edges, and mosasaurs have one, as far as I’m aware..

 

  

  

[Anomotodon]

14 minutes ago, Landon said:

Also it has two cutting edges, if it has serrations I can’t see them without a microscope, they’re small. I know crocs generally don’t have two cutting edges, and mosasaurs have one, as far as I’m aware..

Crocs almost always have at least remnants of carinae (cutting edges), the only exception may be some durophagous crocs with rounded teeth. Mosasaurs can have both, one or none, depending on the species and position in the jaw, plesiosaurs always don’t have any carinae. This tooth is a mosasaur (?Mosasaurus sp., I think juvenile M. beaugei has multiple ridges on the crown but I might be wrong, @Praefectus and @pachy-pleuro-whatnot-odon could be more specific)

[fossil_lover_2277]

6 minutes ago, Anomotodon said:

Crocs almost always have at least remnants of carinae (cutting edges), the only exception may be some durophagous crocs with rounded teeth. Mosasaurs can have both, one or none, depending on the species and position in the jaw, plesiosaurs always don’t have any carinae. This tooth is a mosasaur (?Mosasaurus sp., I think juvenile M. beaugei has multiple ridges on the crown but I might be wrong, @Praefectus and @pachy-pleuro-whatnot-odon could be more specific)

Thank you for the correction!! What tipped you off it was a mosasaur so I don’t mislabel another tooth haha.. Also, could the jaw bone be from a mosasaur too potentially?

Edited August 31, 2021 by Landon

[fossil_lover_2277]

Okay so in the fossil ID section, found out that the tooth is not a theropod dinosaur, but from a mosasaur!

[Anomotodon]

Not sure to be honest. It seems reptilian because of alveoli - tooth sockets - that characterize thecodont dentition. Most bony fish do not have alveoli and their teeth are directly attached to the jaw, but there are also lots of exceptions, like Ichthyodectids - a family to which Xiphactinus belongs. Not saying this jaw might be from one, it’s actually quite unlikely, but there were definitely many other fish with similar morphology.
 

By the way, your shark tooth is definitely Paleogene - likely Serratolamna, which reminded me of another possibility for your mosasaur tooth. In the Paleocene-Eocene of Morocco there were lots of dyrosaurid croc species with different tooth morphologies, most had lots of fine striations (ridges) on the crown, but some had smooth crowns. I’ve seen some jaws from moroccan dyrosaurids with very similar teeth to yours, so that could be another possibility for that tooth, since you have at least some Paleogene material there.

[fossil_lover_2277]

6 minutes ago, Anomotodon said:

Not sure to be honest. It seems reptilian because of alveoli - tooth sockets - that characterize thecodont dentition. Most bony fish do not have alveoli and their teeth are directly attached to the jaw, but there are also lots of exceptions, like Ichthyodectids - a family to which Xiphactinus belongs. Not saying this jaw might be from one, it’s actually quite unlikely, but there were definitely many other fish with similar morphology.
 

By the way, your shark tooth is definitely Paleogene - likely Serratolamna, which reminded me of another possibility for your mosasaur tooth. In the Paleocene-Eocene of Morocco there were lots of dyrosaurid croc species with different tooth morphologies, most had lots of fine striations (ridges) on the crown, but some had smooth crowns. I’ve seen some jaws from moroccan dyrosaurids with very similar teeth to yours, so that could be another possibility for that tooth, since you have at least some Paleogene material there.

That’s fascinating, thank you for the guidance. I assumed Cretaceous (they weren’t labeled) because there were numerous teeth consistent with goblin sharks and Cretolamna (a pic of all the fossils I bought is below)

[Anomotodon]

All of these sharks are Eocene, it’s a mix of Otodus, Serratolamna, Cretolamna (they are known from Eocene although the species is undescribed), possibly Parotodus and ?Jaekelotodus. Tail spines from Myliobatis rays are also Eocene, they were not around in the Cretaceous.

 

In Khouribga phosphates there are deposits ranging from Maastrichtian (Latest Cretaceous) to Ypresian (Early Eocene) and dealers frequently get the age wrong

Edited August 31, 2021 by Anomotodon

[fossil_lover_2277]

38 minutes ago, Anomotodon said:

All of these sharks are Eocene, it’s a mix of Otodus, Serratolamna, Cretolamna (they are known from Eocene although the species is undescribed), possibly Parotodus and ?Jaekelotodus. Tail spines from Myliobatis rays are also Eocene, they were not around in the Cretaceous.

 

In Khouribga phosphates there are deposits ranging from Maastrichtian (Latest Cretaceous) to Ypresian (Early Eocene) and dealers frequently get the age wrong

Hey, I might be good at finding fossils, but my ID skills, def not claiming they’re the best :p my only question is the second tooth from the right on the bottom row, what tells you it’s possibly jaekelotodus (I’m assuming) and not a sand tiger..is it the curvature on the cusps?

[Praefectus]

 

 

I'm thinking Eremiasaurus heterodontus for this. One of the teeth from the middle of the jaw. 

[fossil_lover_2277]

25 minutes ago, Praefectus said:

 

 

I'm thinking Eremiasaurus heterodontus for this. One of the teeth from the middle of the jaw. 

That’s so cool you were able to figure out the exact species! It says online it’s known only from Moroccan Maastrichtian sediments

[pachy-pleuro-whatnot-odon]

Interesting mix of fossils you've got here! Hard to identify, though, but I agree with most of what Tim has expounded already. The phosphate mines at Ouled Abdoun disclose layers dating both to the Eocene and Maastrichtian, so with the thecodont dentition exhibited by your jaw fragment, my first thought was that it could be part of a larger crocodilian jaw. That's because the thecodont condition is indeed often encountered in reptiles and mammals, but less so in fish. Since mosasaurs did not possess thecodont dentition, however, the only options that would fit in terms of both time and place would be either plesiosaurian, Zarafasaura oceanis, or crocodilian, Dyrosaurus phosphaticus. Both would normally be larger and sturdier, but of the two I'd be more inclined towards the elasmosaur Z. oceanis, since those jaws can be very narrow in places and plesiosaur skull bones were often not completely ossified. Also, spacing between the individual alveoli is slightly greater in Dyrosaurus, which, moreover, has slightly convex tooth sockets, not present in your specimen. Compare the below jaws of Z. oceanis

 

 

 

 

with those of D. phosphaticus/sp.:

 

 

(Source: Wikipedia)

 

That having been said, with most of the shark material presented here, it's very well possible that the jaw does, after all, belong to Dyrosaurus phosphaticus, which seems a better match for the matrix that remains in the alveoli.

 

As to the mystery tooth: this, again, could be either Dyrosaurus or a mosasaur. Generally, crocodilians, as Tim explained, indeed have two carinae, which mosasaurs may also have. Eremiasaurus heterodontus, however, has more recurved teeth that are generally more conical and have only an posterior carina (so, on the inner curve). If mosasaurine, I would therefore suggest the tooth belongs to Prognathodon anceps. However, I'm not entirely sure whether the tooth is mosasaurian, since the lingual side of the tooth (here, the less convex side) seems to be set into the carinae somewhat, which is unlike mosasaurs, where the teeth are generally more rounded, but more like those of crocodilians. This would suggest the tooth belongs to Dyrosaurus phosphaticus, which would match the supposition of this collection of fossils coming from the Eocene layers of Morocco. Compare to the below D. phosphaticus tooth crown (which, moreover, nicely illustrates my point about the lingual side being inset into the carinae somewhat):

 

[fossil_lover_2277]

4 hours ago, pachy-pleuro-whatnot-odon said:

Interesting mix of fossils you've got here! Hard to identify, though, but I agree with most of what Tim has expounded already. The phosphate mines at Ouled Abdoun disclose layers dating both to the Eocene and Maastrichtian, so with the thecodont dentition exhibited by your jaw fragment, my first thought was that it could be part of a larger crocodilian jaw. That's because the thecodont condition is indeed often encountered in reptiles and mammals, but less so in fish. Since mosasaurs did not possess thecodont dentition, however, the only options that would fit in terms of both time and place would be either plesiosaurian, Zarafasaura oceanis, or crocodilian, Dyrosaurus phosphaticus. Both would normally be larger and sturdier, but of the two I'd be more inclined towards the elasmosaur Z. oceanis, since those jaws can be very narrow in places and plesiosaur skull bones were often not completely ossified. Also, spacing between the individual alveoli is slightly greater in Dyrosaurus, which, moreover, has slightly convex tooth sockets, not present in your specimen. Compare the below jaws of Z. oceanis

 

 

 

 

with those of D. phosphaticus/sp.:

 

 

(Source: Wikipedia)

 

That having been said, with most of the shark material presented here, it's very well possible that the jaw does, after all, belong to Dyrosaurus phosphaticus, which seems a better match for the matrix that remains in the alveoli.

 

As to the mystery tooth: this, again, could be either Dyrosaurus or a mosasaur. Generally, crocodilians, as Tim explained, indeed have two carinae, which mosasaurs may also have. Eremiasaurus heterodontus, however, has more recurved teeth that are generally more conical and have only an posterior carina (so, on the inner curve). If mosasaurine, I would therefore suggest the tooth belongs to Prognathodon anceps. However, I'm not entirely sure whether the tooth is mosasaurian, since the lingual side of the tooth (here, the less convex side) seems to be set into the carinae somewhat, which is unlike mosasaurs, where the teeth are generally more rounded, but more like those of crocodilians. This would suggest the tooth belongs to Dyrosaurus phosphaticus, which would match the supposition of this collection of fossils coming from the Eocene layers of Morocco. Compare to the below D. phosphaticus tooth crown (which, moreover, nicely illustrates my point about the lingual side being inset into the carinae somewhat):

 

Thanks, I just learned so much reading that. I had literally no idea what I’d bought then, really cool!!!

[Praefectus]

6 hours ago, pachy-pleuro-whatnot-odon said:

Eremiasaurus heterodontus, however, has more recurved teeth that are generally more conical and have only an posterior carina (so, on the inner curve).

 

This is true only for anterior teeth of Eremiasaurus heterodontus. Middle and posterior teeth have both anterior and posterior carina. I have noticed that Eremiasaurus heterodontus teeth are overall more laterally compressed than those of 'Prognathodon' anceps and that a good way to tell the two apart is by their horizontal cross-section. Eremiasaurus heterodontus will be pinched and oval-shaped while most Prognathodon teeth are near circular. 

 

Based on the pictures supplied, I think @Landon's tooth is Eremiasaurus heterodontus sixth-ninth tooth position. 

 

Leblanc et al., 2012

 

Eremiasaurus front teeth

 

Eremiasaurus mid/back teeth

 

 

 

 

[Anomotodon]

This is a very complicated question, because in the Cretaceous-Eocene of Morocco there were lots of Dyrosaurid genera: Dyrosaurus, Ocepesuchus, Arambourgisuchus, Chenanisuchus, Atlantosuchus. Naturally, papers describing these species say very little about their teeth...

 

What I could find from descriptions:

 

Ocepesuchus - no striations or carinae, thin and conical teeth

Arambourgisuchus - robust sharp teeth, posterior carina ends before the base, anterior reaches the base, striations weak or absent

Atlantosuchus - both carinae present, teeth slender, distally curved and conical, labial and lingual surfaces assymetrical, striae present on all teeth but weaker on posteriors

Chenanisuchus - short, robust, transversally compressed, striae absent at least on the external (labial) surface

Dyrosaurus phosphaticus - assymetrical labial and lingual surfaces, both carinae well developed, striae on both sides, weaker in posteriors

 

None of these papers have any close-up photos of teeth. But, based on the descriptions, this tooth seems to fit Arambourgisuchus. I actually think that a lot of of teeth commonly sold as mosasaur are in fact misidentified dyrosaurids

 

Here are some examples from the internet that fit these descriptions

 

Arambourgisuchus

 

Chenanisuchus 

 

 

Atlantosuchus 

 

 

Dyrosaurus

 

 

Ocepesuchus

 

 

 

Edited September 1, 2021 by Anomotodon

[Praefectus]

9 minutes ago, Anomotodon said:

Arambourgisuchus - robust sharp teeth, posterior carina ends before the base, anterior reaches the base, striations weak or absent

 Arambourgisuchus teeth seem to generally be wider in cross-section and more recurved.  OP's tooth is laterally compressed and has anterior and posterior carina that both reach the base the crown.

[Anomotodon]

On 8/31/2021 at 10:06 PM, Praefectus said:

 Arambourgisuchus teeth seem to generally be wider in cross-section and more recurved.  OP's tooth is laterally compressed and has anterior and posterior carina that both reach the base the crown.

 

You are right that some of the teeth I labeled as Arambourgisuchus above might also be Chenanisuchus, since the word description is the only information we have about its teeth... Either way, there are specimens like this with little distal curvature that could be either due to positional variation (anterior-most teeth are usually more recurved, not sure about dentary vs maxillary teeth in crocodiles; that part of Arambourgisuchus dentary seems to be the middle portion) or a different species, which are undoubtedly crocodile. However, I am not saying definitively that the OP's tooth is a crocodile, to be honest, I have no idea how to distinguish these from a mosasaur like Eremiasaurus... The only thing that makes lean towards a Paleocene-Eocene croc is that the rest of OP's fossils seem to be Paleocene-Eocene.

 

[Al Dente]

Is the tip of this tooth clear or highly translucent? Or is this just a color change that I see?
 

 

[Phos_01]

Issn't there a possibility this tooth is Croq? That was my first tooth.
However I hope it belongs to a Theropod. What others said above seems accurate, it looks like the tip of a Arambourgisuchus perhaps. It has no serrations on the sides

[fossil_lover_2277]

13 hours ago, Anomotodon said:

 

You are right that some of the teeth I labeled as Arambourgisuchus above might also be Chenanisuchus, since the word description is the only information we have about its teeth... Either way, there are specimens like this with little distal curvature that could be either due to positional variation (anterior-most teeth are usually more recurved, not sure about dentary vs maxillary teeth in crocodiles; that part of Arambourgisuchus dentary seems to be the middle portion) or a different species, which are undoubtedly crocodile. However, I am not saying definitively that the OP's tooth is a crocodile, to be honest, I have no idea how to distinguish these from a mosasaur like Eremiasaurus... The only thing that makes lean towards a Paleocene-Eocene croc is that the rest of OP's fossils seem to be Paleocene-Eocene.

 

 

8 hours ago, Al Dente said:

Is the tip of this tooth clear or highly translucent? Or is this just a color change that I see?
 

 

 

7 hours ago, Phos_01 said:

Issn't there a possibility this tooth is Croq? That was my first tooth.
However I hope it belongs to a Theropod. What others said above seems accurate, it looks like the tip of a Arambourgisuchus perhaps. It has no serrations on the sides

So I looked at the tooth under a microscope at our molecular bio lab, I can confirm no serrations. However, the “cutting edge” ends in a thinly raised ridge. Also no clear tip

Edited September 2, 2021 by Landon

[pachy-pleuro-whatnot-odon]

On 8/31/2021 at 11:14 PM, Praefectus said:

This is true only for anterior teeth of Eremiasaurus heterodontus. Middle and posterior teeth have both anterior and posterior carina.

 

Makes sense, as this is the case in other mosasaur species as well. However, in that case I might need to re-evaluate what I thought I knew about Eremiasaurus heterodontus, as I may have based myself a bit too much on the below thread, and especially the photograph of the full skull shown there (for the description there, contrary to the photograph, actually also describes compressed, blade-like teeth with both anterior and posterior carinae, whereas these don't seem to be present on the skull featured).

 

On 3/25/2013 at 8:59 PM, jnoun11 said:

 

I also remember this thread featuring a superficially similar tooth that @jnoun11 suggested to be a Prognathodon left anterior maxillary tooth.

 

 

On 8/31/2021 at 11:14 PM, Praefectus said:

Eremiasaurus mid/back teeth

 

Are you sure these are Eremiasaurus heterodontus? For while I do have a huge specimen in my collection that exhibits the recurve and lack of anterior carina apparently typical of anterior E. heterodontus teeth, this set of teeth looks extremely robust to me, much more like a Prognathodon than Eremiasaurus.

 

 

On 9/1/2021 at 4:48 AM, Anomotodon said:

This is a very complicated question, because in the Cretaceous-Eocene of Morocco there were lots of Dyrosaurid genera: Dyrosaurus, Ocepesuchus, Arambourgisuchus, Chenanisuchus, Atlantosuchus.

 

I had no idea there were so many dyrosaurid genera present in the Eocene phosphates! I learned something new today Kudos for compiling this list and providing the visual examples!

 

On 9/2/2021 at 5:57 AM, Anomotodon said:

However, I am not saying definitively that the OP's tooth is a crocodile, to be honest, I have no idea how to distinguish these from a mosasaur like Eremiasaurus... The only thing that makes lean towards a Paleocene-Eocene croc is that the rest of OP's fossils seem to be Paleocene-Eocene.

 

While I can see where the suggestion is coming from, and the provided photographs are definitely wanting for identification, I don't think we can truly use association as a way to pin down the stratigraphic origin of the tooth here. After all, we have absolutely no idea how the vendor assemblage came about (and if my supposition that the jaw is a bit of elasmosaurid jaw, there'd be a mix anyway).

 

That having been said, there's one way in which we can clearly distinguish whether this is a crocodile or mosasaur tooth, at least... This method has to do with the ways in which the tooth crown attaches to the root in both crocodiles and mosasaurs, as crocodiles as thecodont while mosasaur teeth are attached to their root by way of osteocementum or mineralised periodontal ligaments (Leblanc 2019). This difference can be seen at the crown-base, albeit it's often obscured by matrix infill. However, in crocodilians the dental cavity is much wider and deeper than in mosasaurs, which at times have an even almost flat base to their crowns.

 

On 8/31/2021 at 5:07 AM, Landon said:

  

 

The dental cavity shown above is too deep for a mosasaur tooth crown, and I would thus argue that this tooth is crocodilian - something that is also suggested by the near-flat lingual surface of the tooth, as well as what I still believe is a slight inset of the lingual face into the labial one at the carinae. Seeing as the discussion above, I'd no longer simply call this Dyrosaurus phosphaticus, but I would say it's a dyrosaurid. Further identification may be achieved if better photographs are provided from which details such as ornamentation and carinae can be more readily picked up.

[Praefectus]

1 hour ago, pachy-pleuro-whatnot-odon said:

I also remember this thread featuring a superficially similar tooth that @jnoun11 suggested to be a Prognathodon left anterior maxillary tooth.

 

 

Now that's an old thread. I forgot I made that. Looking at it now, I think the ID is Eremiasaurus heterodontus. 

 

1 hour ago, pachy-pleuro-whatnot-odon said:

Are you sure these are Eremiasaurus heterodontus? For while I do have a huge specimen in my collection that exhibits the recurve and lack of anterior carina apparently typical of anterior E. heterodontus teeth, this set of teeth looks extremely robust to me, much more like a Prognathodon than Eremiasaurus.

Yes. Those are pictures of one of the syntypes taken from the 1st author's (A. LeBlanc) blog. 

 

1 hour ago, pachy-pleuro-whatnot-odon said:

The dental cavity shown above is too deep for a mosasaur tooth crown, and I would thus argue that this tooth is crocodilian - something that is also suggested by the near-flat lingual surface of the tooth, as well as what I still believe is a slight inset of the lingual face into the labial one at the carinae. Seeing as the discussion above, I'd no longer simply call this Dyrosaurus phosphaticus, but I would say it's a dyrosaurid. Further identification may be achieved if better photographs are provided from which details such as ornamentation and carinae can be more readily picked up.

Hmm. This is interesting. I didn't think about that. Now I am unsure.