bthemoose Posted August 13, 2020 Share Posted August 13, 2020 I found this shark tooth a few weeks ago along the Calvert Cliffs (Miocene exposure) in Maryland and categorized it as Carcharodon hastalis. Looking at it again, I think it's perhaps Isurus desori. However, while I know C. hastalis can sometimes have cusplets, I'm not sure if that's true for I. desori. What do you think? Was my C. hastalis ID correct or would you label this one I. desori or something else? Whatever you think the correct ID is, if you could help point me to what you see as the defining characteristics, that would be great as well. Thank you! 2 Link to comment Share on other sites More sharing options...
Darktooth Posted August 13, 2020 Share Posted August 13, 2020 I have not seen a Mako with such pronounced cusps before. If this is indeed a mako, I believe that this would be a great example of a rare find. @MarcoSr ( I called in the big guns for some insight) 1 I like Trilo-butts and I cannot lie. Link to comment Share on other sites More sharing options...
bthemoose Posted August 13, 2020 Author Share Posted August 13, 2020 1 minute ago, Darktooth said: I have not seen a Mako with such pronounced cusps before. If this is indeed a mako, I believe that this would be a great example of a rare find. @MarcoSr ( I called in the big guns for some insight) When I first picked it up, I thought it was perhaps Carcharias cuspidata (and I suppose it could still be that), but it looked too robust to me for a sand tiger, so I moved it over to C. hastalis. Link to comment Share on other sites More sharing options...
MarcoSr Posted August 13, 2020 Share Posted August 13, 2020 21 minutes ago, Darktooth said: I have not seen a Mako with such pronounced cusps before. If this is indeed a mako, I believe that this would be a great example of a rare find. @MarcoSr ( I called in the big guns for some insight) Does the tooth have fine crenulations anywhere on the cutting edges? The features that I can see look like Carcharodon subserratus a.k.a. escheri which is very rare from Calvert Cliffs. However, the tooth could also be Carcharodon hastalis. C. subserratus crowns are comparatively narrower than crowns of comparable sized C. hastalis teeth Kent 2018 2 The Cartilaginous Fishes (Chimaeras, Sharks, and Rays) of Calvert Cliffs, Maryland, USA. Marco Sr. 4 "Any day that you can fossil hunt is a great day." My family fossil website Some Of My Shark, Ray, Fish And Other Micros My Extant Shark Jaw Collection Link to comment Share on other sites More sharing options...
bthemoose Posted August 13, 2020 Author Share Posted August 13, 2020 1 hour ago, MarcoSr said: Does the tooth have fine crenulations anywhere on the cutting edges? The features that I can see look like Carcharodon subserratus a.k.a. escheri which is very rare from Calvert Cliffs. However, the tooth could also be Carcharodon hastalis. C. subserratus crowns are comparatively narrower than crowns of comparable sized C. hastalis teeth Kent 2018 2 The Cartilaginous Fishes (Chimaeras, Sharks, and Rays) of Calvert Cliffs, Maryland, USA. Marco Sr. I really need to get a loupe or other magnifier, but I don't see any crenulations with the naked eye, and also don't see any weak serrations. Does that make this most likely C. hastalis? Link to comment Share on other sites More sharing options...
Miocene_Mason Posted August 13, 2020 Share Posted August 13, 2020 That tooth is killer! Doesn’t look like a C. escheri to me, think it’s just an epic example of cusps in Carcharodon hastalis. Anatomical variation at its finest!! Compressed crown and cusps would have been great for catching Small fish, unfortunately many other sharks fulfilled this niche already so this mutation could never catch on. 2 “...whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been and are being evolved.” ~ Charles Darwin Happy hunting, Mason Link to comment Share on other sites More sharing options...
Praefectus Posted August 13, 2020 Share Posted August 13, 2020 Wow! That is a unique tooth. Great find! Link to comment Share on other sites More sharing options...
BellamyBlake Posted August 13, 2020 Share Posted August 13, 2020 It looks exactly like Hastalis barring the cusps. I had no idea they could have cusps, but some of the more experiences folks here digress. Lovely find! Link to comment Share on other sites More sharing options...
MarcoSr Posted August 13, 2020 Share Posted August 13, 2020 9 hours ago, bthemoose said: I really need to get a loupe or other magnifier, but I don't see any crenulations with the naked eye, and also don't see any weak serrations. Does that make this most likely C. hastalis? Without crenulations, I would say that it is a C. hastalis. Marco Sr. 2 "Any day that you can fossil hunt is a great day." My family fossil website Some Of My Shark, Ray, Fish And Other Micros My Extant Shark Jaw Collection Link to comment Share on other sites More sharing options...
bthemoose Posted August 13, 2020 Author Share Posted August 13, 2020 At @MarcoSr's suggestion, I emailed these pictures to Dr. Bretton Kent at the University of Maryland, and he confirmed that this appears to be a lower Carcharodon hastalis tooth. He also mentioned that the cusplets "are as large as any I've seen" on a C. hastalis tooth, so it is indeed an interesting find! 2 Link to comment Share on other sites More sharing options...
Miocene_Mason Posted August 13, 2020 Share Posted August 13, 2020 7 minutes ago, bthemoose said: He also mentioned that the cusplets "are as large as any I've seen" on a C. hastalis tooth, so it is indeed an interesting find! The CMM might find it interesting “...whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been and are being evolved.” ~ Charles Darwin Happy hunting, Mason Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now