Is this a Liopleurodon tooth?

[Ginger0412]

Is this a real Liopleurodon tooth? Forums, please let me know. I appreciate everyone's help! thank you! Scientific name: Liopleurodon sp. Origin: Cambridgesire, England Stratification: Oxford Clay Formation Period: Callovian-Middle Jurassic Size: 31.7 x 19.9 (mm)

[val horn]

It is very pretty, but i have no knowledge, hopefully somebody like @pachy-pleuro-whatnot-odonwill have a educated opinion.

[Ginger0412]

Thank you for your information! Your information has helped me a lot!

[msantix]

Very nice! it is certainly a Pliosaur tooth but I'm not sure about which species it belong to.

Edited October 4, 2022 by msantix

[Ginger0412]

Thank you for teaching! What you taught me really helped me. Thank you very much! !

[pachy-pleuro-whatnot-odon]

Definitely a pliosaur tooth and one of the Oxford Clay thalassophonea (derived pliosaurs). Based on robustness and ornamentation it should be one of the short-symphysis genera, therefore mainly Simolestes and Liopleurodon are in the running. It can be difficult to distinguish between these two, however, especially since this is just a tooth tip. If you look at the below figure from Tarlo (1960) reference work on Upper Jurassic pliosaurs (here reproduced from figure 8 of Madzia, 2016) you'll note that a lot of the illustrated variation can be found exactly at the base of the crown.

 

 

(A) not considered a pliosaur any more; (B) Simolestes vorax, (C) Liopleurodon ferox, (D) Liopleurodon pachydeirus, (E) Pliosaurus andrewsi, and (F) Peloneustes philarchus.

 

Then there's the element of colour, which may indicate the tooth's origin from the Kosmoceras jason zone and identify the tooth as Simolestes vorax. To again quote @paulgdls on this:

  

On 2/3/2021 at 9:10 PM, paulgdls said:

Could well be Simolestes vorax. The colour and ridge coarseness may indicate this species rather than Liopleurodon ferox, the teeth of which tend to have grey enamel see (excerpt from Lesley Noe Phd describing Simolestes vorax teeth characteristics):

 

"The teeth very frequently preserve a `vitreous' texture or lustre and a rich dark brown colour not seen in the
other genera. "

 

Obviously there are other ways to identify pliosaur teeth, of which I've provided a simple branch diagram here (might work it into a visual at some point, as this question does keep popping up a lot). However, I think the below quotes from Noé's PhD thesis, as cited here, may be most informative in this case (where we should read "reticulation" as "fusion"):

  

On 2/10/2021 at 11:48 AM, paulgdls said:

On Simolestes again: "The bottom of the enamel ridges very infrequently displays reticulations, and the
enamel is rarely vermiculated."

 

On Liopleurodon: "Occasionally the enamel ridges bifurcate or
reticulate close to the bottom of the enamel, and rarely additional enamel ridges are added
between the existing ornamentation, some distance above the bottom of the enamel (figure 24)."

 

 

As I see no fusion of the enamel ridges (which may, however, still have been present lower on the tooth), no vermiculation of the enamel itself, the ridges are rather gracile and the colour matches what we might expect for Simolestes vorax, I suspect that this tooth is actually that latter species, not Liopleurodon sp..

 

Hope this helps.