Mystery Madagascar teeth ID help Croc? Pterosaur? Yes I have good proximity

[jikohr]

Hi everyone!

 

I just got in some interesting teeth from the Jurassic of Madagascar Isalo lll Formation (yes I have good proximity. The were found on the outskirts of Boriziny by surface collecting, I included a map) and some of the teeth I'm not sure what they are. My best guess is either Croc or Pterosaur, leaning (hoping) Pterosaur since there is no carina and most have a flattened oval base like the Pterosaur teeth I usually see out of Morocco but then there's one with a circular base that I'm not entirely sure. I saw somewhere that Rhamphorhynchidae can be found within the Isalo, could these be from one of them?

first tooth has CH of 16.5 mm, CBL of 7.11 mm, and CBW of 7.98 mm

second tooth has a CH of 19.98 mm, CBL of 5.26 mm, and CBW of 6.3 mm

 

Any insight is appreciated as always!

Edited April 24, 2023 by jikohr
forgot something

[Troodon]

If you can get a copy of the paper it's based around 4 pterosaur teeth that were collected. Not a pterosaur aficionado do mid-jurassic teeth get that large?

https://www.semanticscholar.org/paper/First-record-of-pterosaurs-(Diapsida%2C-Pterosauria)-Sasso-Pasini/4a80b046471103ceec66b427cbf618b1de8ab39c

 

No idea on the other, if little is published on theropod teeth the only crocodyliform described and published is Raz.

[jikohr]

22 minutes ago, Troodon said:

If you can get a copy of the paper it's based around 4 pterosaur teeth that were collected. Not a pterosaur aficionado do mid-jurassic teeth get that large?

https://www.semanticscholar.org/paper/First-record-of-pterosaurs-(Diapsida%2C-Pterosauria)-Sasso-Pasini/4a80b046471103ceec66b427cbf618b1de8ab39c

 

No idea on the other, if little is published on theropod teeth the only crocodyliform described and published is Raz.

The guy I got them from says he has some publications, hopefully he finally comes through with them. I also asked about the one you recommended since it doesn't look like I can get access to it.

Any other Jurassic Rhamphorhynchidae Pterosaurs to compare to?

[jikohr]

This might be beyond insane, but could the second one be Plesiosaur? It does look like one but, would that even make sense for the Isalo?

@pachy-pleuro-whatnot-odon@Fossildude19 @Troodon You guys are good and dispelling my crazy notions, what do you think?

I googled fresh water Plesiosaur and apparently there were a few small ones at that time found in Africa.

Edited April 25, 2023 by jikohr

[Fossildude19]

Sorry, I have no idea on these things. 

[jikohr]

16 minutes ago, Fossildude19 said:

Sorry, I have no idea on these things. 

It's cool. There really doesn't seem to to be much literature around the fossils in this formation anywhere I look and a lot of what might have been helpful is inaccessible for some reason.

I'm gonna put these off to the side in a special place until one day hopefully more research is done.

[pachy-pleuro-whatnot-odon]

On 4/25/2023 at 12:14 AM, jikohr said:

My best guess is either Croc or Pterosaur, leaning (hoping) Pterosaur since there is no carina and most have a flattened oval base like the Pterosaur teeth I usually see out of Morocco but then there's one with a circular base that I'm not entirely sure. I saw somewhere that Rhamphorhynchidae can be found within the Isalo, could these be from one of them?

first tooth has CH of 16.5 mm, CBL of 7.11 mm, and CBW of 7.98 mm

second tooth has a CH of 19.98 mm, CBL of 5.26 mm, and CBW of 6.3 mm

 

Any insight is appreciated as always!

 

I think crocodile is not a bad guess for the first tooth, seeing both as how diverse crocodilian species were on Madagascar as well as how the striae match expected patterns. The tooth also seems to have a carina visible on the first photograph, which further supports this identification.

Concerning pterosaur tooth identification, I'm unfortunately not at home in that, but believe they're typically more laterally compressed, right? @msantix @FF7_Yuffie

 

11 hours ago, jikohr said:

This might be beyond insane, but could the second one be Plesiosaur? It does look like one but, would that even make sense for the Isalo?

I googled fresh water Plesiosaur and apparently there were a few small ones at that time found in Africa.

 

And while I can't comment on whether plesiosaur would be an option for the Isalo III Formation either - unfortunately, as you have found, information on the fossils of Madagascar in general and marine reptiles in particular is extremely hard to come by (see the below thread for some work I've put in towards that end) - nor whether freshwater plesiosaur would indeed be a possibility at that time - as far as I'm aware plesiosaurs only started exploring freshwater environments within the leptocleididae family, which is mainly restricted to the Cretaceous, even if the below cladogram indicates their origin as in the very latest Jurassic (Tithonian); I'd thus be very interested if you could forward the information you found - the overall morphology of the second tooth, with its smooth root, sub-oval cross-section and mild compression, thin enamel, shallow dental cavity, angle of curvature, slight S-twist towards the apex and anastomosing ridges does seem like a good match for a plesiosaur tooth. And plesiosaurs - in particular elasmosaurs - were certainly around in Madagascar during the Cretaceous, as much as ichthyosaurs seem to have been present during the Jurassic. Maybe the tooth was just misidentified in age/provenance? This seems to be the case for the ichthyosaur jaw I have, which is said to be Triassic, but is clearly Jurassic in morphology...

 

Source: figure 5 from Benson, Ketchum, Naish & Turner (2012).

 

 

[jikohr]

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

 

I think crocodile is not a bad guess for the first tooth, seeing both as how diverse crocodilian species were on Madagascar as well as how the striae match expected patterns. The tooth also seems to have a carina visible on the first photograph, which further supports this identification.

Concerning pterosaur tooth identification, I'm unfortunately not at home in that, but believe they're typically more laterally compressed, right? @msantix @FF7_Yuffie

 

 

And while I can't comment on whether plesiosaur would be an option for the Isalo III Formation either - unfortunately, as you have found, information on the fossils of Madagascar in general and marine reptiles in particular is extremely hard to come by (see the below thread for some work I've put in towards that end) - nor whether freshwater plesiosaur would indeed be a possibility at that time - as far as I'm aware plesiosaurs only started exploring freshwater environments within the leptocleididae family, which is mainly restricted to the Cretaceous, even if the below cladogram indicates their origin as in the very latest Jurassic (Tithonian); I'd thus be very interested if you could forward the information you found - the overall morphology of the second tooth, with its smooth root, sub-oval cross-section and mild compression, thin enamel, shallow dental cavity, angle of curvature, slight S-twist towards the apex and anastomosing ridges does seem like a good match for a plesiosaur tooth. And plesiosaurs - in particular elasmosaurs - were certainly around in Madagascar during the Cretaceous, as much as ichthyosaurs seem to have been present during the Jurassic. Maybe the tooth was just misidentified in age/provenance? This seems to be the case for the ichthyosaur jaw I have, which is said to be Triassic, but is clearly Jurassic in morphology...

 

Source: figure 5 from Benson, Ketchum, Naish & Turner (2012).

 

 

The "Carina" on the first tooth is actually just a little crack, no carina whatsoever. That's on me, photo could be better.

 

I've been corresponding with the guy I got these from and apparently "Plesio" teeth are actually pretty easy to find mixed in with all the spoon shaped sauropod teeth. I actually sent the pics to him asking what that was ad he was the one who suggested Plesiosaur in the most cavalier way possible. They weren't even advertised as being in the lot just "oh yeah that big group of dinosaur teeth from this tiny spot on the map, yeah there's some Plesiosaur teeth mixed in, find 'em all the time". Here's some pics of the other fossils in the lot including lots of little spoon shaped sauropod teeth, some theropod teeth, one that I really believe is Pterosaur, and three that I strongly suspect are also Plesiosaur, all were found in "about a 10 km hunting area". I'm going to ask him some other questions later on today about the "Plesiosaur" teeth and try to get some more details surrounding them. Any other details to ask about or other pictures of the specimens that might help let me know what I can do.

 

first the little spoons:

 

Then the Theropods:

 

The one I will be shocked if it isn't Pterosaur:

 

and the other three I strongly suspect are Plesiosaur. "cf. Plesiosaur"? Is that how you use that?

 

Edited April 26, 2023 by jikohr

[Troodon]

Difficult to tell be if these two have big serrations they are could be Razanandrongobe

 

[msantix]

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

 

I think crocodile is not a bad guess for the first tooth, seeing both as how diverse crocodilian species were on Madagascar as well as how the striae match expected patterns. The tooth also seems to have a carina visible on the first photograph, which further supports this identification.

Concerning pterosaur tooth identification, I'm unfortunately not at home in that, but believe they're typically more laterally compressed, right?

Croc is my guess as well, but I am unfamiliar with teeth from that locality....anyway I don't think it is Pterosaur. 

[pachy-pleuro-whatnot-odon]

19 minutes ago, jikohr said:

The "Carina" on the first tooth is actually just a little crack, no carina whatsoever. That's on me, photo could be better.

 

Hmm... Without the carina, the evidence for it being crocodile is less strong, as these would typically have two carinae and (even if only slightly so) uneven labial and lingual sides. Could therefore well be plesiosaur, since it seems plesiosaur is not uncommon in the area - at least not to the extent I thought they might be or are in the Kem Kem. Even so, I think crocodyloform still remains the best option...

 

19 minutes ago, jikohr said:

I've been corresponding with the guy I got these from and apparently "Plesio" teeth are actually pretty easy to find mixed in with all the spoon shaped sauropod teeth. I actually sent the pics to him asking what that was ad he was the one who suggested Plesiosaur in the most cavalier way possible. They weren't even advertised as being in the lot just "oh yeah that big group of dinosaur teeth from this tiny spot on the map, yeah there's some Plesiosaur teeth mixed in, find 'em all the time". Here's some pics of the other fossils in the lot including lots of little spoon shaped sauropod teeth, some theropod teeth, one that I really believe is Pterosaur, and three that I strongly suspect are also Plesiosaur, all were found in "about a 10 km hunting area". I'm going to ask him some other questions later on today about the "Plesiosaur" teeth and try to get some more details surrounding them. Any other details to ask about or other pictures of the specimens that might help let me know what I can do.

 

Interesting! I wouldn't have expected plesiosaur teeth to be so common, especially not in a freshwater environment. In the freshwater environments I know plesiosaur teeth from - such as the Vectis Formation in the southern UK and the Kem Kem Group - they're usually much rarer...

 

19 minutes ago, jikohr said:

The one I will be shocked if it isn't Pterosaur:

 

I'd be inclined to agree... Seems to big for fish, which, for me, would be the only other option...

 

19 minutes ago, jikohr said:

and the other three I strongly suspect are Plesiosaur. "cf. Plesiosaur"? Is that how you use that?

 

I'd say "cf. Plesiosauria", because "plesiosaur" is not an official name. Another way of putting it would be "Plesiosauria indet.", but you'd use that mostly if you're sure it's plesiosaur and not just something that looks a lot like plesiosaur teeth, as these do...

[jikohr]

12 minutes ago, Troodon said:

Difficult to tell be if these two have big serrations they are could be Razanandrongobe

 

 

20 minutes ago, Troodon said:

Difficult to tell be if these two have big serrations they are could be Razanandrongobe

 

No serrations, only small spoony goodness my good sir. Was going to label them indet. Sauropod. The second one does have this weird groove that goes all the way around the crown though...... Not sure what the deal with that is.

My guy actually mentioned Raz, said they're super rare.

[Troodon]

That groove is just a wear facet see J

SAUROPOD TEETH FROM THE MIDDLE JURASSIC OF MADAGASCAR, AND THE OLDEST RECORD OF TITANOSAURIFORMES by GABRIELE BINDELLINI  and CRISTIANO DAL SASSO 2019

[jikohr]

6 minutes ago, Troodon said:

That groove is just a wear facet see J

SAUROPOD TEETH FROM THE MIDDLE JURASSIC OF MADAGASCAR, AND THE OLDEST RECORD OF TITANOSAURIFORMES by GABRIELE BINDELLINI  and CRISTIANO DAL SASSO 2019

Oh sweet! I'm gonna check out that paper for more info!

[FF7_Yuffie]

To me, the base of the pterosaur tooth looks too round to be a pterosaur. 

[jikohr]

3 hours ago, FF7_Yuffie said:

To me, the base of the pterosaur tooth looks too round to be a pterosaur. 

which one?

[pachy-pleuro-whatnot-odon]

Hmm... I'm actually reconsidering my earlier answer on the teeth being plesiosaur teeth. I think the situation is a bit more complex than that. The below tooth, for example, is one that I'd still clearly identify as plesiosaur:

 

10 hours ago, jikohr said:

 

However, when I look at the below tooth again, I think that I should probably have taken more heed of the horizontal banding at the base of the tooth crown. This is a feature you most consistently see in crocodilian teeth, yet that I haven't seen in plesiosaur teeth. In addition, if you look towards the tooth apex in the first two photographs (the anterior and posterior perspectives), then you'll notice that the striae in those areas fall short of touching upon another ridge that actually runs the full apicobasal height of the tooth uninterruptedly. These ridges are the same kind of carinae you'd see in teleosaurid marine crocodiles, which fit well with a Bathonian age for the assemblage. So, in the below case, I actually think the tooth might be crocodilian after all...

 

On 4/25/2023 at 12:14 AM, jikohr said:

 

A tooth like the one below this might be more of a likely candidate for plesiosaur again, with it's lack of obvious carinae and oval cross-section...

 

10 hours ago, jikohr said:

 

So I think that much like with marine reptile teeth from other locations, here too specimens would need to be examined on a case-by-case basis - preferably in-hand - to determine whether the tooth is plesiosaur or crocodilian...

[jikohr]

47 minutes ago, pachy-pleuro-whatnot-odon said:

Hmm... I'm actually reconsidering my earlier answer on the teeth being plesiosaur teeth. I think the situation is a bit more complex than that. The below tooth, for example, is one that I'd still clearly identify as plesiosaur:

 

 

However, when I look at the below tooth again, I think that I should probably have taken more heed of the horizontal banding at the base of the tooth crown. This is a feature you most consistently see in crocodilian teeth, yet that I haven't seen in plesiosaur teeth. In addition, if you look towards the tooth apex in the first two photographs (the anterior and posterior perspectives), then you'll notice that the striae in those areas fall short of touching upon another ridge that actually runs the full apicobasal height of the tooth uninterruptedly. These ridges are the same kind of carinae you'd see in teleosaurid marine crocodiles, which fit well with a Bathonian age for the assemblage. So, in the below case, I actually think the tooth might be crocodilian after all...

 

 

A tooth like the one below this might be more of a likely candidate for plesiosaur again, with it's lack of obvious carinae and oval cross-section...

 

 

So I think that much like with marine reptile teeth from other locations, here too specimens would need to be examined on a case-by-case basis - preferably in-hand - to determine whether the tooth is plesiosaur or crocodilian...

The mystery deepens...

 

Croc is what I expected honestly and was and am shocked that Plesiosaur could even be a possibility for these. Here are three more teeth for the discussion and also to see if I understand what has been said so far.

The first has no carina and is completely smooth, curved, with what I think is the horizontal band you maybe Plesiosaur but most likely croc with weirdly Plesiosaur like teeth.

The second I believe is another Pterosaur though I could be wrong.

The third is almost certainly croc, I will be astounded if it isn't. Carina on both sides, vertical ridges, the works.

 

Tooth1:

 

tooth2:

 

and tooth 3:

[pachy-pleuro-whatnot-odon]

16 hours ago, jikohr said:

Croc is what I expected honestly and was and am shocked that Plesiosaur could even be a possibility for these.

 

As I said before, I'm not aware of any Jurassic freshwater plesiosaurs. But knowing they existed in the Early Cretaceous, we can't exclude they could've been around earlier as well, especially is lesser studied areas of the world. Mosasaurs, for instance, were comparatively rapid in adapting to freshwater environments... The other option, of course, is convergent evolution

 

16 hours ago, jikohr said:

The first has no carina and is completely smooth, curved, with what I think is the horizontal band you maybe Plesiosaur but most likely croc with weirdly Plesiosaur like teeth.

 

The first tooth appears to be encrusted, obscuring the striations visible at the base of the tooth. Preservation prevents from making out any carinae or horizontal banding. However, when you look at the light area near the top the tooth I the first photograph of it, there's a dark line that runs through it vertically and seems to continue in the light area towards the base of the crown. This could be a carina. In any case, with that degree of curvature, crocodile seems likely.

 

16 hours ago, jikohr said:

The second I believe is another Pterosaur though I could be wrong.

 

Not my expertise, but pterosaur seems well possible...

 

16 hours ago, jikohr said:

The third is almost certainly croc, I will be astounded if it isn't. Carina on both sides, vertical ridges, the works.

 

Yeah, definitely crocodile. Possibly even teleosaurid. Anyway, observe the same degree of curvature as in the first tooth...