What are the different makos?

[SawTooth]

First of all I will make it clear that I have no idea how to spell some of these names, I tried Google but it didn't understand what I was trying to say, so these are just guesses that sound about right. So my question is what are the different makos (by this I mean modern makos, hastalis, desori, and any others you can name) and how do identify them from each other?

Thanks!

[Fossildude19]

Link to ELASMO.COM

 

Use the links at the bottom of the page to navigate.

[Top Trilo]

Wikipedia's page, https://en.wikipedia.org/wiki/Isurus lists several species under the genus Isurus

However I know taxonomy for some hasn't been straight forward. https://en.wikipedia.org/wiki/Cosmopolitodus, I'm not sure whether species in the genus Cosmopolitodus are makos or white sharks or neither. One of the shark experts will mostly pop in soon and help more than I could.

[Meganeura]

51 minutes ago, Top Trilo said:

Wikipedia's page, https://en.wikipedia.org/wiki/Isurus lists several species under the genus Isurus

However I know taxonomy for some hasn't been straight forward. https://en.wikipedia.org/wiki/Cosmopolitodus, I'm not sure whether species in the genus Cosmopolitodus are makos or white sharks or neither. One of the shark experts will mostly pop in soon and help more than I could.

Based on the myriad of reading I've done since finding one on Wednesday and trying to figure out which it was - C. Hastalis - whether Carcharodon or Cosmopolitodus seem to be agreed to belong to the line that led to Great Whites, and not Isurus - the Mako sharks. However there seems to be a lot of dissent/debate about whether or not C. Hastalis should be split - as there's a broad form and a narrow form of the teeth, the broad form sometimes being referred to as C. Plicatilis and the narrow as the original C. Hastalis. There also seems to be a few others that fit the same criteria - like C. Planus - the hooked white shark, though I haven't read much on those yet.

Also any actual experts please correct me if I'm wrong, I'm honestly still trying to figure out what the differences between the Broad and Narrow forms are specifically, as some teeth (Like the one I got from Harry) seem to fall into "This could be either". At least, to my untrained eye.

[DD1991]

9 hours ago, Meganeura said:

Based on the myriad of reading I've done since finding one on Wednesday and trying to figure out which it was - C. Hastalis - whether Carcharodon or Cosmopolitodus seem to be agreed to belong to the line that led to Great Whites, and not Isurus - the Mako sharks. However there seems to be a lot of dissent/debate about whether or not C. Hastalis should be split - as there's a broad form and a narrow form of the teeth, the broad form sometimes being referred to as C. Plicatilis and the narrow as the original C. Hastalis. There also seems to be a few others that fit the same criteria - like C. Planus - the hooked white shark, though I haven't read much on those yet.

Also any actual experts please correct me if I'm wrong, I'm honestly still trying to figure out what the differences between the Broad and Narrow forms are specifically, as some teeth (Like the one I got from Harry) seem to fall into "This could be either". At least, to my untrained eye.

The papers by Cione et al. (2012) and Ehret et al. (2012) assign the extinct lamnid taxa assigned to Cosmopolitodus (including the type species of Cosmopolitodus, C. hastalis) to the same genus as the great white shark based on comparisons with the teeth of Carcharodon carcharias. However, Collaretta et al. (2017) and Yun (2022) do not consider Cosmopolitodus to be congeneric with Carcharodon, even though they agree with Ehret et al. (2012) that C. hastalis and C. plicatilus are not congeneric with the living mako sharks.

 

Collareta, A., Landini, W., Chacaltana, C., Valdivia, W., Altamirano-Sierra, A., Urbina-Schmitt, M. & Bi-anucci, G., 2017. A well preserved skeleton of the fossil shark Cosmopolitodus hastalis from the late Miocene of Peru, featuring fish remains as fossilized stomach contents. Rivista Italiana di Paleontologia e Stratigrafia 123: 11–22.

 

Yun, C., 2021. A tooth of the extinct lamnid shark, Cosmopolitodus planus comb. nov. (Chondrichthyes, Elasmobranchii) from the Miocene of Pohang City, South Korea. Acta Palaeontologica Romaniae 18 (1): 9–16. doi:10.35463/j.apr.2022.01.02. 

[Meganeura]

6 hours ago, DD1991 said:

The papers by Cione et al. (2012) and Ehret et al. (2012) assign the extinct lamnid taxa assigned to Cosmopolitodus (including the type species of Cosmopolitodus, C. hastalis) to the same genus as the great white shark based on comparisons with the teeth of Carcharodon carcharias. However, Collaretta et al. (2017) and Yun (2022) do not consider Cosmopolitodus to be congeneric with Carcharodon, even though they agree with Ehret et al. (2012) that C. hastalis and C. plicatilus are not congeneric with the living mako sharks.

 

Collareta, A., Landini, W., Chacaltana, C., Valdivia, W., Altamirano-Sierra, A., Urbina-Schmitt, M. & Bi-anucci, G., 2017. A well preserved skeleton of the fossil shark Cosmopolitodus hastalis from the late Miocene of Peru, featuring fish remains as fossilized stomach contents. Rivista Italiana di Paleontologia e Stratigrafia 123: 11–22.

 

Yun, C., 2021. A tooth of the extinct lamnid shark, Cosmopolitodus planus comb. nov. (Chondrichthyes, Elasmobranchii) from the Miocene of Pohang City, South Korea. Acta Palaeontologica Romaniae 18 (1): 9–16. doi:10.35463/j.apr.2022.01.02. 

Super interesting but now I’m even more confused!

[SawTooth]

Thanks, now can someone tell me the difference between the teeth of the hastalis and modern makos.

[ThePhysicist]

On 8/5/2022 at 9:01 AM, SawTooth said:

First of all I will make it clear that I have no idea how to spell some of these names, I tried Google but it didn't understand what I was trying to say, so these are just guesses that sound about right. So my question is what are the different makos (by this I mean modern makos, hastalis, desori, and any others you can name) and how do identify them from each other?

Thanks!

 

Calling sharks "mako" or "white shark" is the common name we give to a shark, and those names usually correspond to the genus. 

 

Members of the genus Isurus are the "makos." The extant species are I. oxyrinchus and I. paucus (the shortfin and longfin makos, respectively). Extinct makos include I. desori and I. retroflexus, though there has been some debate as to whether these fossil forms are the same as the modern species. The earliest appearance of Isurus seems to be in the Late Oligocene ~ 27 million years ago. (Wikipedia claims Cretaceous, but looking at the papers referenced, I suspect they mistook Cretoxyrhina.)

 

Isurus teeth are narrow, grasping teeth; ideal for catching fish! elasmo.com is a good place for learning how to ID these teeth. I only have a few pics handy for ID'ing them.

 

Left: modern shortfin mako (I. oxyrinchus), right: extinct shortfin mako (I. desori)

 

 

Members of the genera Carcharodon and Cosmopolitodus are the "white sharks." This includes the only living species C. carcharias (the great white), and many extinct species including C. hubbelli, C. hastalis, C. escheri, C. planus and possibly C. plicatilis. The earliest appearance of the white sharks seems to be the Early Miocene ~ 20 million years ago. (I've seen Oligocene claimed but can't find any publications to support it.)

 

Carcharodon/Cosmopolitodus teeth are generally broader than Isurus, better for cutting. Early on, the white sharks had smooth cutting edges, eventually some evolved serrations as their diets shifted more to marine mammals.

 

  

 

 

 

The naming of these species is messy for many reasons. One, because people used to believe these extinct white sharks were true "makos" and placed them in Isurus. We however recently learned that hastalis, planus et al. are more closely related to the modern great white than the mako sharks. Collectors still occasionally call the extinct white sharks "makos" for that reason.

 

Also, as aforementioned, there's the splitter/lumper debate going on about whether these extinct white sharks belong in Carcharodon or this extinct genus Cosmopolitodus. It's tricky business since we don't have DNA from all these fish to go by. (There was yet another extinct white shark genus Carcharomodus, but I don't think anyone uses it anymore.)

 

Identifying/naming the species of white shark teeth is fairly straightforward until you come to C. hastalis. There appear to be two similar tooth forms that have been assigned to C. hastalis, one narrow, the other broad. The narrow kind is definitely called C. hastalis, the broad kind has been split by some people from the narrow form into another species, most commonly C. plicatilis (less commonly, C. xiphodon, but I don't think anyone uses that name anymore). How broad does it have to be to be C. plicatilis vs C. hastalis? It's not clear to me yet.

 

 

Oversimplified ID's:

C. hastalis/plicatilis - no serrations (can have broad or narrow blades)

C. planus - no serrations, with hooked upper teeth

C. escheri - looks like C. hastalis, but with fine serrations, only found in the Atlantic

C. hubbelli - fine, irregular serrations that decrease in size towards the tip, only found in the Pacific

C. carcharias - large, triangular, irregular serrations

Edited August 7, 2022 by ThePhysicist

[Al Dente]

Some of these teeth can be very difficult to ID. One of the papers mentioned above may have misidentified the genus of the shark they described. The paper “A well preserved skeleton of the fossil shark Cosmopolitodus hastalis from the late Miocene of Peru, featuring fish remains as fossilized stomach contents. Rivista Italiana di Paleontologia e Stratigrafia 123: 11–22.” shows the attached photo of the teeth. They decided this was a juvenile C. hastalis but said that ID might not be correct.

 

 

[Meganeura]

1 hour ago, Al Dente said:

Some of these teeth can be very difficult to ID. One of the papers mentioned above may have misidentified the genus of the shark they described. The paper “A well preserved skeleton of the fossil shark Cosmopolitodus hastalis from the late Miocene of Peru, featuring fish remains as fossilized stomach contents. Rivista Italiana di Paleontologia e Stratigrafia 123: 11–22.” shows the attached photo of the teeth. They decided this was a juvenile C. hastalis but said that ID might not be correct.

 

 

Just to add on - I found this C Hastalis yesterday - and I’m pretty sure it’s narrow, but… it’s so hard to tell. I’ve also heard that the difference could solely be due to sexual dimorphism - though I’m not sure what the arguments for/against this are.

 

[Al Dente]

10 minutes ago, Meganeura said:

Just to add on - I found this C Hastalis yesterday - and I’m pretty sure it’s narrow, but… it’s so hard to tell. I’ve also heard that the difference could solely be due to sexual dimorphism - though I’m not sure what the arguments for/against this are.

There is probably more going on than gender differences. In North Carolina, hastalis (narrow form) is found in the Miocene Pungo River Formation while the broad form is found in the younger Pliocene Yorktown Formation. 

[Meganeura]

10 minutes ago, Al Dente said:

There is probably more going on than gender differences. In North Carolina, hastalis (narrow form) is found in the Miocene Pungo River Formation while the broad form is found in the younger Pliocene Yorktown Formation. 

But not vice-versa? Wouldn't that just outright disprove sexual-dimorphism then? Or at least make an incredibly strong case against it?

[Gareth_]

With C. hastalis, I never see people talk about anterior, lateral or posterior teeth.... why? 

The extant Shortfin Mako has some awesome dentition, because it's on topic and for no other reason, here are a couple of pics of a large jaw 
(I'm happy to take pics or any teeth or sections of its jaw if anyone wants a closer look)

 

[bthemoose]

48 minutes ago, Gareth_ said:

With C. hastalis, I never see people talk about anterior, lateral or posterior teeth.... why? 

People do. Check out some extreme posterior C. hastalis in this thread, for example: