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HoppeHunting

Megalodon or Chubutensis?

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HoppeHunting

Hello everyone,

 

If you saw my most recent trip report, you know that I just found my first meg tooth! However, I'm not entirely sure whether the tooth is from Carcharocles megalodon or Carcharocles chubutensis. The tooth was found at Bayfront Park/Brownies Beach, which is the northernmost part of the Calvert Cliffs. The sediments exposed in the cliffs here are from the Calvert Formation, roughly 18-22 million years old. This would be right around the time when the great Megalodon first emerged. I remember reading that the majority of megateeth found at Brownies are chubs, but that megs have also been found there. What I'd like to know is which one my tooth is: Meg or Chub? It looks to me like if the tooth were complete, it would have the defining residual cusps of chubutensis, but unfortunately the blade is broken on both sides right by the root. The bourlette is missing, but that is a characteristic of every shark in the mega lineage so that doesn't really matter. The tooth is approximately 1 3/4 inches, and not quite as thick as I would've expected. As you can see on my trip report and Hop 5 post, my current ID for this tooth is C. chubutensis, but that is subject to change should someone with better knowledge on megatooth identification give their opinion. One last possibility is that it may be a transitional meg, meaning the shark was a blurred line between megalodon and chubutensis. Any input is appreciated. Thanks!

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WhodamanHD

Really, it’s kinda impossible to divide them. Date is the only thing that really defines them. If it comes from brownies I would say chub, especially seeing as potential cusps are broken off. I remember I read somewhere that’s why they were abandoned, they make the tooth weaker.

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Darktooth

Some of the meg and mako teeth that I have found start to split were the blade meets the root as they dry out. So the fact that your tooth is missing small portions were cusps "could have been" is not indicative of cusps ever being present in the first place. The fact is that with those portions missing there is no way to know for sure. Label it which ever suits you. Here are two of the best megs that I have found at Brownies. Not a hint of cusp.

20190127_222407.jpg

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Darktooth

20190127_222416.jpg

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Darktooth

Note that on the second tooth one side of the blade is missing about the same spot as on yours. The other side is intact.

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Al Dente
6 hours ago, Darktooth said:

Label it which ever suits you. Here are two of the best megs that I have found at Brownies. Not a hint of cusp.

Your teeth look to be lowers. Some lower anterior chubutensis teeth seem to lack cusps. There are two partial associated chubutensis dentitions in the “Geology and Paleontology of the Lee Creek Mine” volume 3. Both sets lack cusps on some of the lower teeth.

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Darktooth
4 hours ago, Al Dente said:

Your teeth look to be lowers. Some lower anterior chubutensis teeth seem to lack cusps. There are two partial associated chubutensis dentitions in the “Geology and Paleontology of the Lee Creek Mine” volume 3. Both sets lack cusps on some of the lower teeth.

Thanks for the info @Al Dente. But I have also found uppers at this location as well.  These are no longer in possession but have been posted on the forum in the past. I have collected uppers, lowers, and posteriors both with and without cusps. Also it is believed that juvenile  Megs had cusps as well. The point I was trying to make with my earlier posts was that I think that making a Identification based on what is a more common find in a particular  area as well as diagnostic features that are not present, (the cusps), is kind of foolhardy in my opinion. Now I am definitely not an expert and I am trying to learn new information as much as I can, so I would ask you is there any other way to differentiate the two species when both are present, and what do you believe his tooth to be, and why?

 

Sincerly Dave

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MarcoSr
15 hours ago, HoppeHunting said:

 The tooth was found at Bayfront Park/Brownies Beach, which is the northernmost part of the Calvert Cliffs. The sediments exposed in the cliffs here are from the Calvert Formation, roughly 18-22 million years old.

 

Fairhaven is the northern most part of Calvert Cliffs.  The Brownies Beach cliffs have formations from the Calvert Formation Fairhaven Member zone 3B at the base of the cliffs up to the Choptank Formation Boston Cliffs Member zone 19 high up in the cliffs.  Ward 2008 "Stratigraphy of the Calvert, Choptank, and St. Marys Formations (Miocene) in the Chesapeake Bay Area, Maryland and Virginia."

 

You can find both megs and chubs at Brownies Beach coming out of the different formations there.

 

Marco Sr.

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Darktooth
31 minutes ago, MarcoSr said:

 

Fairhaven is the northern most part of Calvert Cliffs.  The Brownies Beach cliffs have formations from the Calvert Formation Fairhaven Member zone 3B at the base of the cliffs up to the Choptank Formation Boston Cliffs Member zone 19 high up in the cliffs.  Ward 2008 "Stratigraphy of the Calvert, Choptank, and St. Marys Formations (Miocene) in the Chesapeake Bay Area, Maryland and Virginia."

 

You can find both megs and chubs at Brownies Beach coming out of the different formations there.

 

Marco Sr.

What is your opinion on the ID of his tooth?

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MarcoSr
2 hours ago, Darktooth said:

What is your opinion on the ID of his tooth?

 

The two areas that you really need to see are damaged/missing.  I think the root erosion on the one side gives a false impression that there had to be a cusp there.  The other side looks like there wasn't a cusp or bulge there.  All that being said I'm probably 51/49 meg.

 

Marco Sr.

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Darktooth
18 hours ago, Darktooth said:

Some of the meg and mako teeth that I have found start to split were the blade meets the root as they dry out. So the fact that your tooth is missing small portions were cusps "could have been" is not indicative of cusps ever being present in the first place. The fact is that with those portions missing there is no way to know for sure. Label it which ever suits you. Here are two of the best megs that I have found at Brownies. Not a hint of cusp.

20190127_222407.jpg

 

18 minutes ago, MarcoSr said:

 

The two areas that you really need to see are damaged/missing.  I think the root erosion on the one side gives a false impression that there had to be a cusp there.  The other side looks like there wasn't a cusp or bulge there.  All that being said I'm probably 51/49 meg.

 

Marco Sr.

Thank-you Marco, that was what I was trying to address in my above post.

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