The Great Cosmopolitodus

[Al Dente]

4 hours ago, WhodamanHD said:

Considering it most likely evolved from hastilis I’d call it Carcharodon escheri...

“Isurus” escheri has been placed into its own genus. It is now Carcharomodus escheri. “A partial Skeleton of a new Lamniform Mackerel Shark from the Miocene of Europe”.

[Miocene_Mason]

3 hours ago, Al Dente said:

“Isurus” escheri has been placed into its own genus. It is now Carcharomodus escheri. “A partial Skeleton of a new Lamniform Mackerel Shark from the Miocene of Europe”.

That’s a good thing to know, is it still thought to have evolved from C. Hastilis

 

[SailingAlongToo]

On 2/23/2018 at 10:52 PM, WhodamanHD said:

IMO the serrations and some differences in the morphology should denote a seperate genus, but I still think they should all be “Makos” including the extant great white. But I’ve been met with opposition when postulating it before, really its semantics in the end. We humans need to get around to defining a species and a genus, and how general each type is.

 

And, then there is recognizing and accepting variability among species. I will offer Homo sapiens as an example. Significant differences exist between a Mayan, an Eastern European, Asians and someone from sub-Saharan Africa, including skull size and shape, bone structure, appearance. etc. A million years from now, I wonder if future paleontologists or anthropologists will/would "lump" these examples in the same species as we are now, or would they "split" them out into different Genus and species because of the obvious differences.

 

In the end, lumpers are going to lump things together into neat groups, splitters want to split things off by making new or other groups and some people aren't happy either way and want to change things (most of the time with valid scientific reasoning, though not always without disagreement among the scientific community.)

 

With the megalodon, I simply refer to it as a megalodon. I refer to hastalis as hastalis. At least on TFF and the fossil circles I frequent, most everyone knows what I'm talking about and referring to when I use the species. I realize that is not always the case.

[Miocene_Mason]

@SailingAlongToo that’s getting into biological species concept vs Morphological species concept. Almost any two dog breeds can reproduce but their morphology is completely different, whereas copes grey tree frog/grey tree frogs (identical in almost every respect except chromosomes) usually produce infertile offspring. The Linnaean system is a artificial construct, nature does not obey it; therefore it’s rarely works in every case. But at least we can try to get it reasonably uniform. I just say C. hastilis, makes it work for both sides. 

[Sagebrush Steve]

1 hour ago, WhodamanHD said:

I just say C. hastilis, makes it work for both sides. 

But aren’t you only supposed to do that after you have first said the full name? 

[Miocene_Mason]

4 minutes ago, Sagebrush Steve said:

But aren’t you only supposed to do that after you have first said the full name? 

If it’s miocene I assume everyone will know what I’m talking about (not some sort of plant or whatever non-shark C. Hastilis s exist). The genus name is transient, who knows what it will be a year from now (as it should be, science is a perpetually evolving subject.

[ynot]

22 minutes ago, Sagebrush Steve said:

But aren’t you only supposed to do that after you have first said the full name? 

Yes, but many do not follow the rules.

[Kane]

37 minutes ago, Macrophyseter said:

Yes, it is inproper to abbreviate the genus without stating what it stands for first, but in a forum, I think most people would know what it already stands for and properness isnt that nessesary.

You mean "improper."  Using the correct form is part of what we strive to maintain here as a standard of excellence, and as part of our longstanding reputation as a repository of knowledge.  

[ynot]

43 minutes ago, Macrophyseter said:

I think most people would know what it already stands for and properness isnt that nessesary.

What about the newbies that have never heard of these things.

 

9 minutes ago, Kane said:

 Using the correct form is part of what we strive to maintain here as a standard of excellence, and as part of our longstanding reputation as a repository of knowledge.

Definitely do not want to forget the forums standard of excellence!

[Coco]

Hi,

On 25/02/2018 at 10:58 PM, Macrophyseter said:

Yes, it is improper to abbreviate the genus without stating what it stands for first, but in a forum, I think most people would know what it already stands for and properness isnt that nessesary.

 

On 25/02/2018 at 11:34 PM, Kane said:

You mean "improper."  Using the correct form is part of what we strive to maintain here as a standard of excellence, and as part of our longstanding reputation as a repository of knowledge.  

And what about foreigner who haven't necessary your species in their country, or the one who are interested in coral, trilobits, sea urchins, herbivore ? Don't they have the right to learn new things ? C. hastalis is probably Carcharias hastalis or Cosmopolitodus hastalis if it doesn't change, but would not it be Carcharodon hastalis or Carcharocles hastalis for a beginning or a not specialist of the sharks ? Especially when we read that the ex Isurus is of the family of the great white...

 

One of the great strengths of this forum is that it is the richest in all internet and that it is an inexhaustible source of learning and knowledge. Then a small effort is nothing with regard to what it can bring to each of us !

 

Coco

[siteseer]

On February 22, 2018 at 5:28 PM, HoppeHunting said:

I have some questions surrounding the extinct species of Giant White Shark, Cosmopolitodus hastalis. I think it was a fascinating creature, but for reason it doesn't seem to be brought up much. As far as I know, it was a very large shark that lived during the Miocene Epoch, and scientists believe it to be a possible ancestor to the extant Great White Shark, the biggest and meanest shark of our present day oceans. What I'd like to know is what was this shark really like? Did it look similar to the Great White? How do we think it behaved? How exactly does it fit into the lineage of the Great White? How big was it? Did it share the seas, or even possibly become prey for, the mighty O. megalodon? And finally, WHY do people call it "Mako" if it clearly isn't one?? Obviously, not all of these questions have concrete answers but I'd like to hear what you all know about the species. Google search results can only tell so much. Do you know of any good sources where I could read up about it in greater detail? I just think it's a really cool species, and I'd love to know more about it. Thanks!

 

It seems generally accepted now that Carcharodon hastalis is the direct ancestor of the great white.  The Greenland shark and sixgill shark can also reach 20 feet long so it might not be the largest of the predatory sharks.

 

I would think that it didn't look too different.  We might assume that the teeth were the slowest part of the body to change noticeably and overall body shape might not have changed much either.  It's possible in the early evolution of hastalis that it did not have the form of warm-bloodedness that the great white has.  C. hastalis appeared in the Early Miocene, a very warm time - the second warmest time in the whole Cenozoic so far - and this warm time lasted into the Middle Miocene.  Worldwide climates began a cooling trend by about 10 million years ago leading into the ice ages of the Pleistocene.  The Late Miocene world was what the great white was born in.

 

Judging from teeth, C. hastalis was in the same size range as a great white.  Remember that modern great white teeth are rarely over 2-2 1/4 inches.  Fossil great white and hastalis teeth are found over 3 inches (not common but I don't think any modern great white teeth have been found that large).  From that it could be said that hastalis and Pliocene great whites averaged larger in size than modern great whites.  Maybe someone else here has a better idea of that.

 

C. hastalis has been found in the same layers as Carcharocles megalodon.  It's found in Early Miocene layers on the east coast of North America but is not seen until the Middle Miocene on the west coast.

 

C. hasalis was originally described as a mako in the 19th century because that was how it was classified based on what they understood at the time.  People like to use fast-and-easy terms for everything but extinct animals present a challenge to that.  It's hard to have a common name for something you've never seen alive.  Collectors and researchers have called it a mako for years so it's a hard habit to break.

 

Various members have talked about this shark over the years on this forum.  You can do a search for it and get a lot of results.

 

 

 

You can read more about hastalis on elasmo.com.

 

 

[sixgill pete]

@HoppeHunting I always have and probably always will refer to C. hastalis as a "mako" or broad tooth "mako". It's habit as @siteseer stated. Many of us do that. It does not mean we are not aware of the current classification, it is just habit.