Jurassic Pliosaur Teeth from Oxford Clay

[Alston Gee]

I recently found two pliosaur teeth were on sale on online auction site. One was listed as “Simolestes sp.”, and another was identified as “Liopleurodon sp.”. What’s your thoughts? Are they real Jurassic pliosaur teeth, or they belong to something else?

[Alston Gee]

@pachy-pleuro-whatnot-odon The pattern of striations on the first tooth indeed looks like Simolestes vorax. What’s your thoughts? 

[pachy-pleuro-whatnot-odon]

So you're the one who ended up buying them, are you? Not bad teeth! Certainly the first one is rather nice. However, to judge from the carinae which I'm seeing, that first one is not a pliosaur tooth, but rather a sizeable partial Dakosaurus maximus crocodile tooth. The other is very typical for what's identified as Liopleurodon sp. from the Faringdon Sponge Gravels. You should be able to find multiple other examples of these if you search here on TFF. Below are two of mine

 

[Alston Gee]

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

So you're the one who ended up buying them, are you? Not bad teeth! Certainly the first one is rather nice. However, to judge from the carinae which I'm seeing, that first one is not a pliosaur tooth, but rather a sizeable partial Dakosaurus maximus crocodile tooth. The other is very typical for what's identified as Liopleurodon sp. from the Faringdon Sponge Gravels. You should be able to find multiple other examples of these if you search here on TFF. Below are two of mine

 

Fortunately, I purchased the second tooth yesterday because the striation and shape of the second tooth certainly mark it as a pliosaur tooth. The pattern of striations and trihedral structure of the first tooth almost trick me. 

[Alston Gee]

@pachy-pleuro-whatnot-odonHi Pachy, one of my friends recently found a plesiosaur tooth in South China (Zigong, Sichuan Province). However, he failed to identify whether this tooth should be considered as Polycotylid sp. or any other plesiosaur species. There is no record of pliosaur sp. being discovered in South China. The only plesiosaur species discovered in Sichuan Province, China is Sinopliosaur weiyuanensis, which has been described as a “nomen dubium” (Buffetaut et al., 2008). What are your thoughts on this?

[pachy-pleuro-whatnot-odon]

3 hours ago, Alston Gee said:

@pachy-pleuro-whatnot-odonHi Pachy, one of my friends recently found a plesiosaur tooth in South China (Zigong, Sichuan Province). However, he failed to identify whether this tooth should be considered as Polycotylid sp. or any other plesiosaur species. There is no record of pliosaur sp. being discovered in South China. The only plesiosaur species discovered in Sichuan Province, China is Sinopliosaur weiyuanensis, which has been described as a “nomen dubium” (Buffetaut et al., 2008). What are your thoughts on this?

 

 

It's certainly an interesting tooth, with these densely-packed fine striations all around and the tooth apex labially being devoid of striae. What age is it?

 

My first inclination with respect to identification would be to lean towards teleosaurid marine crocodile, seeing as the tooth is both rather robust yet the striations fine. Sturdy teeth like these are, shape-wise, more closely aligned with pliosaurs, because, with polycotylids being cryptoclidids, their teeth are much more slender, being more closely allied with elasmosaurian teeth. At the same time, the striae on pliosaur teeth are much bolder and sharper in nature than the ones found on this tooth, which is the reason 'Sinopliosaurus' fusuiensis was confused with Siamosaurus suteethorni (Buffetaut, Suteethorn, Tong and Amiot, 2008; Wikipedia). Teleosaurid marine crocodiles, like Macrospondylus bollensis (well-known from the Early Jurassic deposits at Holzmaden), however, do occasionally have rather robust teeth, especially machimosaurid species.

 

 

(source: fig. 5 from Benson, Ketchum, Naish & Turner, 2012)

 

 

Here are some examples of teeth attributed to 'Steneosaurus' sp. from Holzmaden for comparison.

 

 

 

A 'Steneosaurus' sp. tooth from the Stonesfield Slates in the UK.

 

Some teleosaurid teeth from Peterborough in the UK.

 

A Machimosaurus hugii tooth from the Lourinhã Formation in Portugal.

 

And a Machimosaurus sp. tooth from the Oxford Clay at Peterborough.

 

[Alston Gee]

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

 

It's certainly an interesting tooth, with these densely-packed fine striations all around and the tooth apex labially being devoid of striae. What age is it?

 

My first inclination with respect to identification would be to lean towards teleosaurid marine crocodile, seeing as the tooth is both rather robust yet the striations fine. Sturdy teeth like these are, shape-wise, more closely aligned with pliosaurs, because, with polycotylids being cryptoclidids, their teeth are much more slender, being more closely allied with elasmosaurian teeth. At the same time, the striae on pliosaur teeth are much bolder and sharper in nature than the ones found on this tooth, which is the reason 'Sinopliosaurus' fusuiensis was confused with Siamosaurus suteethorni (Buffetaut, Suteethorn, Tong and Amiot, 2008; Wikipedia). Teleosaurid marine crocodiles, like Macrospondylus bollensis (well-known from the Early Jurassic deposits at Holzmaden), however, do occasionally have rather robust teeth, especially machimosaurid species.

 

 

(source: fig. 5 from Benson, Ketchum, Naish & Turner, 2012)

 

 

Here are some examples of teeth attributed to 'Steneosaurus' sp. from Holzmaden for comparison.

 

 

 

A 'Steneosaurus' sp. tooth from the Stonesfield Slates in the UK.

 

Some teleosaurid teeth from Peterborough in the UK.

 

A Machimosaurus hugii tooth from the Lourinhã Formation in Portugal.

 

And a Machimosaurus sp. tooth from the Oxford Clay at Peterborough.

 

I agree. The striations on this tooth are more similar to those on marine crocodiles than to pliosaurs. How about the following teeth? Do they belong to pliosaur or something else? These teeth were also discovered in Southwestern China and named rhomaleosaridae.

[pachy-pleuro-whatnot-odon]

41 minutes ago, Alston Gee said:

I agree. The striations on this tooth are more similar to those on marine crocodiles than to pliosaurs. How about the following teeth? Do they belong to pliosaur or something else? These teeth were also discovered in Southwestern China and named rhomaleosaridae.

 

Those are some awesome teeth!

 

Presumably, by their identification as rhomaleosaurid they're of Late Triassic, Early Jurassic age? Shape and size certainly suggest rhomaleosaurid is a possibility if that age is correct, although it's difficult to say with absolute certainty. Below is an example of a rather similar looking tooth from a Termatosaurus albertii from the Upper Muschelkalk of Bettborn in Moselle, France. The species is variably considered either a rhomaleosaurid (as I believe it to be as well) or a phytosaur (source). Similarly, the teeth above look more plesiosaurian than phytosaurian to me, although I've arguably got little experience with phytosaurs.

 

[Alston Gee]

@pachy-pleuro-whatnot-odonHi Pachy, I recently found two tooth fossils in the Lower Shamiaoxi Formation in Zigong, Sichuan, Southwestern China. The general shape and pattern of the striations suggest they should be certain types of marine reptiles. My first inclination with respect to identification would be to lean towards the freshwater crocodile. There are only two species of freshwater crocodiles being discovered in the Shamiaoxi Formation, which are Hsisosuchus sp. and Sunosuchus sp.. In this sense, I would categorize these teeth as "Goniopholididae indet.". What are your thoughts on this?

 

[Alston Gee]

Just now, Alston Gee said:

@pachy-pleuro-whatnot-odonHi Pachy, I recently found two tooth fossils in the Lower Shamiaoxi Formation in Zigong, Sichuan, Southwestern China. The general shape and pattern of the striations suggest they should be certain types of marine reptiles. My first inclination with respect to identification would be to lean towards the freshwater crocodile. There are only two species of freshwater crocodiles being discovered in the Shamiaoxi Formation, which are Hsisosuchus sp. and Sunosuchus sp.. In this sense, I would categorize these teeth as "Goniopholididae indet.". What are your thoughts on this?

 

The age is Middle Jurassic.

[Alston Gee]

On 6/28/2023 at 1:20 PM, Alston Gee said:

@pachy-pleuro-whatnot-odonHi Pachy, one of my friends recently found a plesiosaur tooth in South China (Zigong, Sichuan Province). However, he failed to identify whether this tooth should be considered as Polycotylid sp. or any other plesiosaur species. There is no record of pliosaur sp. being discovered in South China. The only plesiosaur species discovered in Sichuan Province, China is Sinopliosaur weiyuanensis, which has been described as a “nomen dubium” (Buffetaut et al., 2008). What are your thoughts on this?

•  

@pachy-pleuro-whatnot-odonThe age of this tooth is also Middle Jurassic. The pattern of striations on this tooth shares some similarities with Sunosuchus sp. teeth from the Middle Jurassic of Kirghisia (see the figure below). Both this tooth and Sunosuchus sp. teeth from Kirghisia are slender, finely striated, and subcircular in the cross-section of the tooth crown. I noticed that there is a slight labiolingual flattening of the tooth crown increasing from the tip to the base, which is common in Sunosuchus specimens. I believe this tooth should be Sunosuchus sp. indet., or generally speaking, Goniopholididae indet.

 

 

 

 

[Alston Gee]

@pachy-pleuro-whatnot-odon

[Alston Gee]

@Troodon Hi Troodon, do you have any thoughts regarding the identification of the marine reptile teeth mentioned above?

[Troodon]

Not really, not my area of knowledge

[pachy-pleuro-whatnot-odon]

Sorry for arriving late at the party! I was abroad last week when my laptop's battery wouldn't charge any more, so I've had to keep updates - including those for work - to an absolute minimum, as I had to do most things from my phone only. The issue has since been resolved, however, so I'm now trying to catch up on outstanding questions

 

Unfortunately, I, too, have little experience in the geographical area concerned, so am afraid I won't be of much help either. The general shape of the first tooth, its ornamentation and - if I'm making this out correctly - the (apical) presence of a carina would suggest some kind of crocodyliform does indeed seem quite reasonable, especially if two genera are known from your general area. With the apparent absence of a carina, seeming apical labiolingual compression, and type of striations it has, this tooth could potentially be a plesiosaur tooth, something along the lines of cryptoclididae (or elasmosauridae - although those wouldn't have been around yet in the Middle Jurassic). Hard to say without knowing more about the depositional context (particularly marine vs. terrestrial), and without knowing whether other cryptoclidid finds are know from the area. In the meantime, as you've observed certain morphological similarities between Sunosuchus sp. teeth and the teeth you found, I'd say your safest bet is to simply stick to that for your identification.

[Alston Gee]

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

Sorry for arriving late at the party! I was abroad last week when my laptop's battery wouldn't charge any more, so I've had to keep updates - including those for work - to an absolute minimum, as I had to do most things from my phone only. The issue has since been resolved, however, so I'm now trying to catch up on outstanding questions

 

Unfortunately, I, too, have little experience in the geographical area concerned, so am afraid I won't be of much help either. The general shape of the first tooth, its ornamentation and - if I'm making this out correctly - the (apical) presence of a carina would suggest some kind of crocodyliform does indeed seem quite reasonable, especially if two genera are known from your general area. With the apparent absence of a carina, seeming apical labiolingual compression, and type of striations it has, this tooth could potentially be a plesiosaur tooth, something along the lines of cryptoclididae (or elasmosauridae - although those wouldn't have been around yet in the Middle Jurassic). Hard to say without knowing more about the depositional context (particularly marine vs. terrestrial), and without knowing whether other cryptoclidid finds are know from the area. In the meantime, as you've observed certain morphological similarities between Sunosuchus sp. teeth and the teeth you found, I'd say your safest bet is to simply stick to that for your identification.

Thanks for your informative reply! I will ask my friend to send the first tooth to the local paleontological research institution for further analysis.

[pachy-pleuro-whatnot-odon]

24 minutes ago, Alston Gee said:

Thanks for your informative reply! I will ask my friend to send the first tooth to the local paleontological research institution for further analysis.

 

If you're intending to send off the potential plesiosaur tooth, then I just noticed that I made a typo and that should be the second tooth. The first, to me, seems crocodyliform, whereas the second could potentially be plesiosaur... (I wrote "this tooth", though when I did I had the second tooth in mind).

[Alston Gee]

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

 

If you're intending to send off the potential plesiosaur tooth, then I just noticed that I made a typo and that should be the second tooth. The first, to me, seems crocodyliform, whereas the second could potentially be plesiosaur... (I wrote "this tooth", though when I did I had the second tooth in mind).

Thanks for your clarification , Pachy! How about the black one? Does the black one look like Goniopholididae indet. (or Sunosuchus sp.)?

[pachy-pleuro-whatnot-odon]

4 hours ago, Alston Gee said:

Thanks for your clarification , Pachy! How about the black one? Does the black one look like Goniopholididae indet. (or Sunosuchus sp.)?

 

Yeah, based on the presence of a carina, I'd say that's indeed a croc-tooth. I actually described both in my original comment, however conflated their description in my comment... It should've been like this:

 

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

Tooth 1 (darker)

The general shape of the first tooth, its ornamentation and - if I'm making this out correctly - the (apical) presence of a carina would suggest some kind of crocodyliform does indeed seem quite reasonable, especially if two genera are known from your general area.

 

Tooth 2 (lighter)

With the apparent absence of a carina, seeming apical labiolingual compression, and type of striations it has, this tooth could potentially be a plesiosaur tooth, something along the lines of cryptoclididae (or elasmosauridae - although those wouldn't have been around yet in the Middle Jurassic). Hard to say without knowing more about the depositional context (particularly marine vs. terrestrial), and without knowing whether other cryptoclidid finds are know from the area.

 

Both

In the meantime, as you've observed certain morphological similarities between Sunosuchus sp. teeth and the teeth you found, I'd say your safest bet is to simply stick to that for your identification.

 

Sorry for all the confusion! 

[Alston Gee]

@pachy-pleuro-whatnot-odon Hi Pachy. From the comments you posted few months ago, I was still unsure how you identified the tooth below as "Liopleurodon ferox" instead of other species of pliosaurs. I noticed this tooth has striae on both labial and lingual emamel surfaces (no ridges). Liopleurodon ferox teeth usually have no labial ornamentation, while Simolestes vorax teeth are typically fully ornamented all around. would the pattern of striation on the tooth enamel suggest that this tooth is more likely to be Simolestes sp. instead of Liopleurodon ferox?

Edited October 2, 2023 by Alston Gee

[pachy-pleuro-whatnot-odon]

8 hours ago, Alston Gee said:

@pachy-pleuro-whatnot-odon Hi Pachy. From the comments you posted few months ago, I was still unsure how you identified the tooth below as "Liopleurodon ferox" instead of other species of pliosaurs. I noticed this tooth has striae on both labial and lingual emamel surfaces (no ridges). Liopleurodon ferox teeth usually have no labial ornamentation, while Simolestes vorax teeth are typically fully ornamented all around. would the pattern of striation on the tooth enamel suggest that this tooth is more likely to be Simolestes sp. instead of Liopleurodon ferox?

 

While it is true that where derived thalassophonean teeth are concerned a buccal surface devoid of striations is a good indication of the tooth being attributable to Liopleurodon sp., the inverse is, unfortunately, not true. And, in fact, much more determinative than whether the labial surface of the tooth is smooth or ornamented is the type of striations observed - that is, their boldness, where they start and end, and how they intertwine. Have a look at this post for more information. Also, since this specimen comes from the reworked Faringdon Sponge Gravels from the Wicklesham Pit, where most pliosaur tooth finds are attributed to L. ferox, this is likely also the case here, seeing as the boldness of the striations and poor preservation of the specimen.

[Polybranchiaspidida]

@pachy-pleuro-whatnot-odonHi Pachy, I bought one tooth fossil in the Lower Shamiaoxi Formation in Sichuan, Southwestern China.But I don’t know it’s ID.Can you help me?

[Polybranchiaspidida]

Another photo

Edited January 25 by Polybranchiaspidida

[Polybranchiaspidida]

2 minutes ago, Polybranchiaspidida said:

[Polybranchiaspidida]

Is it a freshwater crocodile tooth?