4.2 inch Chubutensis

[dongmin]

This time, it is a 4.2 inch Chubutensis tooth discovered in Bobert, South Carolina that will be included in the shark tooth collection!  The cusps aren't that prominent, but I think they're great teeth!

[rocket]

wow, fantastic serration!!! 

Great one!

[Balance]

when you have a minute to educate a novice. 
What is the noticeable difference that makes this a Chub instead of a Meg? I am aware they are both mega sharks but I can’t see the difference with my limited knowledge. 
 

Thanks 

 

Jp

[dongmin]

7 minutes ago, Balance said:

초보자를 교육할 시간이 있을 때. 
메그가 아닌 처브가 되는 눈에 띄는 차이점은 무엇인가요? 나는 둘 다 거대 상어라는 것을 알고 있지만 제한된 지식으로 차이점을 볼 수 없습니다. 
 

감사해요 

 

일본

The difference between Megalodon teeth and Chubutensis teeth is that they have protruding cusps. Unlike Megalodon, Chubutensis has cusps on both sides as shown in the picture!

[Kikokuryu]

3 minutes ago, Balance said:

What is the noticeable difference that makes this a Chub instead of a Meg?

Age of the rocks. This is the problem with "species". Species don't really exist, or the concept stops working when the sample size is too big and complete.

 

Since Otodus chubutensis is currently assumed to have evolved into Otodus megalodon, you get later stage chubs that are very similar to the early stage megs. You also naturally will get individuals within O. megalodon that would still look like O. chubutensis.

[dongmin]

13 minutes ago, rocket said:

와, 환상적인 톱니!!! 

훌륭해요!

thank you 😊 

[Harry Pristis]

See this:  elasmo.com

[Balance]

Thank you , Harry. I’ve bookmarked the website for future use too. For what it’s worth, whomever is responsible for the “readability” of the info on elasmo does an incredible job of making it accessible to a wide level of educate. 
 

So, Florida Specifically:

 

Pre- Miocene species would be limited to discovery in the areas where the Ocala and Suwannee limestone are present? Meaning that in the Peace river the earliest that’s represented would be the early Miocene versions of the Chubutensis? 
 

The cusps…  if this is a can of worms just put the top back on… I feel like it’s a big question:

 

why would the evolution out of a cusp feature be different than a mammal evolving the removal of a pre molar tooth? I guess I’m confused as to why sharks evolved into different species because of simple dental changes but other genus evolved over their existence and were not reclassified as separate species? 
 

Jp

 

C. aksuaticus  (MENNER, 1928) [late Early Eocene]

C. auriculatus (BLAINVILLE, 1818) [early Middle Eocene]

C. sokolovi  (JAEKEL, 1895) [late Middle Eocene to Early Oligocene]

C. angustidens (AGASSIZ, 1843) [Early Oligocene]

C. chubutensis AMEGHINO, 1906 [Late Oligocene]

C. megalodon  (AGASSIZ, 1835 or 1837) [Miocene]

 

 

[Shellseeker]

Well, Jp  

I will leave it to others who pay more attention to Megatooths than I to answer your questions. 

I am just going to add a photo so you will know when you find one of those Juvenile Megs with Cusps.. I believe that I was hunting with @Sacha when I picked this up...

[Fin Lover]

@Balance, I would also call the original tooth a meg.  I have no idea where Bobert, South Carolina is (and can't find it on Google) but I know in the Charleston area, the professionals say that actual chubs are rare.  

 

It's obviously open to interpretation.  I'm not saying it happened in this case, but I have seen where people claimed to have a "rare chub" because that sounds better and can demand more money than a "late angustidens".

 

Edit: Perhaps Bobert is supposed to be Beaufort.  That would make sense.

Edited May 4 by Fin Lover

[digit]

Keep in mind that the various taxa assigned to the mega-toothed sharks represent what is known as a chrono-species series. Starting with Otodus obliquus (Paleocene) and then on to Carcharocles auriculatus (Eocene), C. angustidens (Oligocene), C. chubutensis (Early Miocene), and finally C. megalodon (Mid Miocene) (though the genus is subject to scientific debate). The trend was for the teeth to get bigger and lose the side cusps while gaining serrations. Many juvenile megs have quite pronounced side cusps and this may be an atavistic holdover from earlier forms.

 

I have seen Florida 'ricks' (C. auriculatus) and some 'angies' (C. angustidens) but they seem to be limited to northern Florida (where older formations can be found near the surface). Some of the 'megs' may well be 'chubs' but when the teeth are found not in the original formation but in a lag deposit in a river bed it is hard to get a handle on the age to say for sure. The tooth in question in this post is more likely a meg than a chub based mainly on size. Top size for chubs is around 5" with the majority being well less than this. Judging by the beefy size of this tooth and the relatively minor size bumps trying to be size cusps, I'd likely consider this a nice meg.

 

The Carolinas have more older older formations and the side-cusped teeth are certainly more common up there. A bunch of years ago I had the opportunity to go dive the Meg Ledges off Wilmington, NC (miles out out in 140' of water). Found some nice megs (but most with excessive enamel peeling) and a few nice chubs. This was one of my nicer ones:

 

Cheers.

 

-Ken