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I'm preparing to put these teeth up into a plaque to showcase the evolution of C. megalodon (a much disputed topic in and of itself). I just acquired the second to left tooth from a dealer in Florida who claims the tooth is a C. auriculatus and the middle tooth was from another dealer who claims it's a C. angustiden. I realize that size in this scenario doesn't matter and I should pay more attention to the serrations and defined cusps but I'm beginning to wonder if the middle tooth is a C. auriculatus because of the increased number of serrations and more defined cusps and the one to it's left could be a C. angustiden. I'm considering swapping them for the display but I'm not sure if that would be accurate. I've read a number of articles that argue that the C. angustiden and C. auriculatus where just a large O. obliquus. That's another debate. Should these all be classified under Otodus rather than Carcharocles? I'm leaning towards Otodus because from an evolutionary stance that would make for sense. The teeth on the right side (left to right) are C. chubutensis and C. megalodon both from Calvert Cliffs, MD. What are your thoughts on this subject? FYI @SailingAlongToo @WhodamanHD @Kurt Komoda @Peat Burns

 

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Do or do not. There is no try. - Yoda

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Hey!

The definition of the cusps is due to it being anterior (lower?) in position, which I’ve noticed seem to have more pronounced cusps for some reason. The range of variation is pretty wide in cusps and serrations are better judges, and the best being site and time period. It’s a very well represented lineage which should make it easier but that it shows us all the little chronospecies in between which brings up the debate over what denotes a species.

 

As for the Otodus vs. Carcharocles debate, it’s still being debated but I personally think Otodus will pan out. It makes more sense and prevents paraphylly. I call my teeth O. megalodon, etc.

 

What articles are these? Otodus obliquus and Otodus auriculatus are definitely different species, both have juveniles and adults as well as large specimens. One also has serrations. Actually, here’s a picture of a part of my evolution set with only juveniles, excluding the Cretalamna (Cretalamna sp. then Otodus sokolovi which is basically in between O. auriculatus and O. angustidens, then angustidens, then O. megalodon). Here you can see that they are definitely not Otodus obliquus.

 

 All your teeth seem correctly labeled to me.  Nice set!

BEDCEAE2-6803-4D69-8331-079196FC0871.jpeg

 

Dont know why the letters are doing what what they are.

“...whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been and are being evolved.” ~ Charles Darwin

Happy hunting,

Mason

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1 hour ago, WhodamanHD said:

(Cretalamna sp. then Otodus sokolovi which is basically in between O. auriculatus and O. angustidens

I thought sokolovi was in between angusteidens and chubutensis? :headscratch:

If you're a fossil nut from Palos Verdes, San Pedro, Redondo Beach, or Torrance, feel free to shoot me a PM!

 

 

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2 minutes ago, Macrophyseter said:

I thought sokolovi was in between angusteidens and chubutensis? :headscratch:

That’s not what I thought but I have been wrong before. I believe they come from the late Eocene of Morocco and occasionally Europe and elsewhere, the gap between early-mid Eocene auriculatus and Oligocene angustidens. Also sometimes spelled sokolowi. 

“...whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been and are being evolved.” ~ Charles Darwin

Happy hunting,

Mason

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1 hour ago, WhodamanHD said:

That’s not what I thought but I have been wrong before. I believe they come from the late Eocene of Morocco and occasionally Europe and elsewhere, the gap between early-mid Eocene auriculatus and Oligocene angustidens. Also sometimes spelled sokolowi. 

Wait, I misread your statement and thought that you said that sokolovi is between akusaticus and auriculatus and I also miswrote my claim, intending to say auriculatus instead of chubutensis. I swear I have some sort of dyslexia, apologies for the confusion :doh!:. So I guess I don't have anything to dispute with because I agreed with you anyways. Still, I decided to do some research on this to be sure.

 

Apparently, "sokolovi" is the correct spelling (named after Sokolov), but has commonly been misspelled as "sokolowi", probably because both spellings sound so similar.

There aren't that many articles written regarding sokolovi, much less any that analyze its possible evolutionary relationship within the Carcharocles/Otodus genus. I have only found two papers directly giving sokolovi a specific placement within a lineage.

 

Diedrich (2013) places sokolovi as the direct precursor to angusteidens. However, he also places auriculatus, chubutensis, and Palaeocarcharodon in the Carcharodon lineage with Carcharodon gibbesi transitioning between chubutensis and carcharias, a species that has never existed in modern papers before this; which he never explained any backstory of, work out a Systematic Paleontology for, or even show a fossil example, giving me the impression that he just made it up. Therefore, his works are often extremely controversial, with at least one of the minimally few studies that cite him (Trif and Vlad, 2016) remarking that some of the placement proposals are unclear and unsubstantial. You probably remember what Mikael Siverson commented about Diedrich's proposal that Cretoxyrhina mantelli should be Isurus mantelli and part of the true mako lineage.

 

The other is Trif and Vlad (2016), where they conclude the progression as: auriculatus -> sokolovi -> angusteidens -> chubutensis -> megalodon.

 

If we are to assume that the progression from aksuaticus -> megalodon is characterized by the refining of serrations and decreasing/disappearance of cusplet size (along with others), there is some evidence that sokolovi is still more advanced than auriculatus. The only papers I can find comparing dental features of sokolovi and other otodonts are from Trif and Vlad (2016), where they state that sokolovi teeth are more finely serrated that than of auriculatus, and Kriwet et al (2016) where they quote "The rather narrow central cusp, the distinctly mesiodistally elongated and rather low root with basally flattened root lobes, and the serration pattern of the mesially preserved cusplet also support its assignment to C. sokolovi rather than to C. auriculatus. Lateral teeth of C. auriculatus have sturdier roots, which are rather high with almost vertical, slightly concave lateral margins in labial and lingual views, not basally flattened root lobes, a more robust central cusp, and coarser serrated lateral cusplets."

If you're a fossil nut from Palos Verdes, San Pedro, Redondo Beach, or Torrance, feel free to shoot me a PM!

 

 

Mosasaurus_hoffmannii_skull_schematic.png

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@WhodamanHD alright I'll stick with that configuration though I've heard some debates that C. auriculatus and C. angustiden are the same shark. Trying to find an exact article but can't seem to find one but I've heard some speculate that these two sharks were the same beast. Here's a funny article for you: http://www.lowcountrygeologic.com/FossilSharkTeeth/Carcharoclesangustidens/tabid/53/Filter/187n201/Default.aspx C. angustidens is not the ancestor of C. carcharias. Come on people. Great White sharks came from Lamniforms and C. angustidens came from O. obliqus.

Do or do not. There is no try. - Yoda

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@Macrophyseter yes the Russian paleontologists seem to have a different viewpoint than the Americans. I've heard these opposing views a few times.

Do or do not. There is no try. - Yoda

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2 minutes ago, Fossil-Hound said:

alright I'll stick with that configuration though I've heard some debates that C. auriculatus and C. angustiden are the same shark. Trying to find an exact article but can't seem to find one but I've heard some speculate that these two sharks were the same beast. Here's a funny article for you: http://www.lowcountrygeologic.com/FossilSharkTeeth/Carcharoclesangustidens/tabid/53/Filter/187n201/Default.aspx

I believe you gave the wrong link, this one only directs me to a site selling angustidens teeth, and the descriptions clearly states that the two sharks are different. :headscratch:

 

5 minutes ago, Fossil-Hound said:

C. angustidens is not the ancestor of C. carcharias. Come on people. Great White sharks came from Lamniforms and C. angustidens came from O. obliqus.

Pretty obvious at this point, but I guess science is still something capable of revealing something small that can overturn all of our understandings, even if it seems like common sense. I mean, the late 1800s/early 1900s works in physics including that of Einstein could be an example.

 

5 minutes ago, Fossil-Hound said:

yes the Russian paleontologists seem to have a different viewpoint than the Americans. I've heard these opposing views a few times.

Diedrich is a German paleontologist, not a Russian one.

If you're a fossil nut from Palos Verdes, San Pedro, Redondo Beach, or Torrance, feel free to shoot me a PM!

 

 

Mosasaurus_hoffmannii_skull_schematic.png

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10 hours ago, Macrophyseter said:

I believe you gave the wrong link, this one only directs me to a site selling angustidens teeth, and the descriptions clearly states that the two sharks are different. :headscratch:

 

Pretty obvious at this point, but I guess science is still something capable of revealing something small that can overturn all of our understandings, even if it seems like common sense. I mean, the late 1800s/early 1900s works in physics including that of Einstein could be an example.

 

Diedrich is a German paleontologist, not a Russian one.

There was a Russian paleontologist who made the argument. I'll need to read up on the Diedrich.

Do or do not. There is no try. - Yoda

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On 10/16/2018 at 6:25 PM, Fossil-Hound said:

I'm preparing to put these teeth up into a plaque to showcase the evolution of C. megalodon (a much disputed topic in and of itself). I just acquired the second to left tooth from a dealer in Florida who claims the tooth is a C. auriculatus and the middle tooth was from another dealer who claims it's a C. angustiden. I realize that size in this scenario doesn't matter and I should pay more attention to the serrations and defined cusps but I'm beginning to wonder if the middle tooth is a C. auriculatus because of the increased number of serrations and more defined cusps and the one to it's left could be a C. angustiden. I'm considering swapping them for the display but I'm not sure if that would be accurate. I've read a number of articles that argue that the C. angustiden and C. auriculatus where just a large O. obliquus. That's another debate. Should these all be classified under Otodus rather than Carcharocles? I'm leaning towards Otodus because from an evolutionary stance that would make for sense. The teeth on the right side (left to right) are C. chubutensis and C. megalodon both from Calvert Cliffs, MD. What are your thoughts on this subject? FYI @SailingAlongToo @WhodamanHD @Kurt Komoda @Peat Burns

 

fullsizeoutput_1e9d.thumb.jpeg.5e78aefea92e8c67ca3bdd3893030dda.jpeg

Where are the two teeth you purchased from and what ages? O. auriculatus are Eocene teeth, O. angustidens are Oligocene. early Oligocene angustidens are very similar in appearance to late Eocene auriculatus. Latest Oligocene angustidens are very similar in appearance to the earliest O. chubutensis. 

Bulldozers and dirt Bulldozers and dirt
behind the trailer, my desert
Them red clay piles are heaven on earth
I get my rocks off, bulldozers and dirt

Patterson Hood; Drive-By Truckers

 

image.png.0c956e87cee523facebb6947cb34e842.png May 2016  MOTM.png.61350469b02f439fd4d5d77c2c69da85.png.a47e14d65deb3f8b242019b3a81d8160.png.b42a25e3438348310ba19ce6852f50c1.png May 2012 IPFOTM5.png.fb4f2a268e315c58c5980ed865b39e1f.png.1721b8912c45105152ac70b0ae8303c3.png.2b6263683ee32421d97e7fa481bd418a.pngAug 2013, May 2016, Apr 2020 VFOTM.png.f1b09c78bf88298b009b0da14ef44cf0.png.af5065d0585e85f4accd8b291bf0cc2e.png.72a83362710033c9bdc8510be7454b66.png.9171036128e7f95de57b6a0f03c491da.png Oct 2022

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13 hours ago, Fossil-Hound said:

@sixgill pete the middle tooth and second to left where recently purchased. No info besides the species was provided.

Without provenance, I would be hesitant I.D.ing either tooth beyond O. indet.

Bulldozers and dirt Bulldozers and dirt
behind the trailer, my desert
Them red clay piles are heaven on earth
I get my rocks off, bulldozers and dirt

Patterson Hood; Drive-By Truckers

 

image.png.0c956e87cee523facebb6947cb34e842.png May 2016  MOTM.png.61350469b02f439fd4d5d77c2c69da85.png.a47e14d65deb3f8b242019b3a81d8160.png.b42a25e3438348310ba19ce6852f50c1.png May 2012 IPFOTM5.png.fb4f2a268e315c58c5980ed865b39e1f.png.1721b8912c45105152ac70b0ae8303c3.png.2b6263683ee32421d97e7fa481bd418a.pngAug 2013, May 2016, Apr 2020 VFOTM.png.f1b09c78bf88298b009b0da14ef44cf0.png.af5065d0585e85f4accd8b291bf0cc2e.png.72a83362710033c9bdc8510be7454b66.png.9171036128e7f95de57b6a0f03c491da.png Oct 2022

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I agree with sixgill pete on being uncertain for those two teeth. Without confirmation of age, Differentiating between morphological differences will be difficult, but based on my inferences from Trif and Vlad (2016), auriculatus teeth should be more coarsely serrated than the more finer serrations of angusteidens, if you can compare.

 

On 10/16/2018 at 3:25 PM, Fossil-Hound said:

Should these all be classified under Otodus rather than Carcharocles?

Carcharocles is by no means invalid, but if you are one who disapproves of paraphyly within the generic range, then Otodus would be your go. It really depends on if you're a lumper or splitter.

 

If you're a fossil nut from Palos Verdes, San Pedro, Redondo Beach, or Torrance, feel free to shoot me a PM!

 

 

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