Cosmopolitodus or Carcharodon or Isurus? Cast your vote!

[Miocene_Mason]

There are many debates over nomenclature in the paleontological world, and although our say has little to do with any decision made, I thought it would be fun to see what it would be like if we did decide such matters. Today, I ask your opinions on one of these. This is the debate over the placement of the deceased shark that goes by the species name hastilis. After a lengthy talk on a random thread (sorry mods) with @Macrophyseter I thought it would be intresting to see others view points. You have three choices, Isurus the genus in which the makos sit, long held to be the genus where hastilis belongs, Carcharodon which is the genus of the great white which is widely held to be the successor of hastilis via escheri and hubbelli, or Cosmopolitodus  the proposed Genus for hastilis, planus, escheri, and a few other sharks. Be sure to explain your reasoning below. Here is a picture of hastilis and Carcharodon carcharias partially for your reference and partially to show off

As an added incentive, which ever one wins out will be on the label for hastilis in the evolution set of megalodon and the white shark I'm working on. Have fun!

[Miocene_Mason]

In my opinion, the teeth are distant enough from Isurus to warrant a different genus, but close enough to the great white to be in its genus. I also believe this to be the case with escheri and hubbelli. 

[Macrophyseter]

So you actually decided to do it.

[Miocene_Mason]

5 minutes ago, Macrophyseter said:

So you actually decided to do it.

Of course! To be honest, the community here matchs some scientific institutions in collective knowledge (plus it's fun!)

[Macrophyseter]

And you also ended up deleting a few seconds of my work unintentionally xD But ill just retype it here

 

So many people are super confused about the original coinings of the three taxons, so Ill clear it up. Isurus was the placement for hastalis by Agassiz in 1843 in his famous shark paper. In 1995, Cosmopolitodus was coined as an alternative name after it was found that hastalis was more related to great whites than makos. The Carcharodon placement was a suggestion from a 2012 paper. So its Isurus -> Cosmopolitodus -> Cosmopolitodus or Carcharodon.

[Miocene_Mason]

Just now, Macrophyseter said:

And you also ended up deleting a few seconds of my work unintentionally xD But ill just retype it here

 

So many people are super confused about the original coinings of the three taxons, so Ill clear it up. Isurus was the placement for hastalis by Agassiz in 1843 in his famous shark paper. In 1995, Cosmopolitodus was coined as an alternative name after it was found that hastalis was more related to great whites than makos (The original 1995 paper isnt in the public internet, so the best I could find was paleontologist David Wards' ancient paper regarding it which where he agreed to with some evidence, and which was when Cosmopolitodus became a known genus). The Carcharodon placement was a suggestion from a 2012 paper. So its Isurus -> Cosmopolitodus -> Cosmopolitodus or Carcharodon.

Sorry for messing up your typing! Thanks for the clarification as well!

[sixgill pete]

Personally I prefer Cosmopilotodus. I agree they do not belong in Isurus and am not so sure about Carcharodon.  But I do usually write it out as Cosmopolitodus (Carcharodon) hastalis.

[Al Dente]

49 minutes ago, sixgill pete said:

Personally I prefer Cosmopilotodus. I agree they do not belong in Isurus and am not so sure about Carcharodon.  But I do usually write it out as Cosmopolitodus (Carcharodon) hastalis.

Until very recently I had been labeling my fossils in a similar manner, with an alternate genus name in parentheses. Someone pointed out to me that this is incorrect. By ICZN rules, if there is a name in parentheses between genus and species, it is the name of the subgenus. I’m not sure of the proper way to write an alternative genus. Maybe someone here knows.

[sixgill pete]

6 minutes ago, Al Dente said:

Until very recently I had been labeling my fossils in a similar manner, with an alternate genus name in parentheses. Someone pointed out to me that this is incorrect. By ICZN rules, if there is a name in parentheses between genus and species, it is the name of the subgenus. I’m not sure of the proper way to write an alternative genus. Maybe someone here knows.

 

Interesting Eric. @MarcoSr any thoughts or info on this? 

[Tidgy's Dad]

The old name should be referred to as (syn.. name) after the new name,if one wants to be helpful, so for example : 

Itagnostus interstrictus (syn. Peronopsis interstricta) 

[Tidgy's Dad]

For the question , i believe that Isurus covered too many distantly related forms and was far too generalized, but is it far enough away from the great white to warrant a different genus?

I think so, especially when compared to planus and escheri. 

So,  I go with Cosmopolitodus.

[Miocene_Mason]

Talk about a thread revival! Interesting points being made, thus far cosmopolitodus is winning by one vote. I voted for Carcharodon, my reasoning being its extreme morphological closeness to hastilis. If Otodus might be extended to megalodon, then I think that Carcharodon should be extended to hastilis. Now I think maybe you could take the planus, escheri and hastilis group into some sort of subgenus (maybe cosmopolitodus). Also, hastilis morphology seems to differ by place, maybe warranting subspecies in my view. Keep the debate rolling, it’s been very educational so far!

[sixgill pete]

5 hours ago, WhodamanHD said:

 If Otodus might be extended to megalodon, then I think that Carcharodon should be extended to hastilis.

 

I do not necessarily but into megalodon belonging to Otodus. But, it is the current scientific view. Last I knew of anyways.

[MarcoSr]

5 hours ago, sixgill pete said:

 

Interesting Eric. @MarcoSr any thoughts or info on this? 

 

Don

 

I go with Carcharodon as the genus for hastalis.  Plenty of scientific evidence that hastalis was a direct ancestor of the extant Carcharodon carcharias.  Also just compare the teeth.  I don't think serrations alone should change a genus.

 

I don't label my fossils in my displays.  I used to but got tired of changing out labels with all of the name changes over the years.  Besides I know what they are.

 

I would use aka with hastalis for a label if you felt you needed to note multiple genera.  For example: Carcharodon hastalis aka Cosmopolitodus hastalis.

 

Marco Sr.

[Miocene_Mason]

39 minutes ago, sixgill pete said:

 

I do not necessarily but into megalodon belonging to Otodus. But, it is the current scientific view. Last I knew of anyways.

I don’t either, but even Carcharocles auriculatus and megalodon are more different than hastilis and the GW shark. Guess it’s the old lumpers v splitters debate.

[Miocene_Mason]

So we have 3 to 3 cosmo and carch, and one for Isurus. Would whoever submitted that vote care to explain your view? If you do not, that’s fine too, I’m just naturally curious.