Posterior Cretalamna Or Otodus Or . . .

[Harry Pristis]

The teeth are separated by a gap in the middle of the paper on the first pic. The Cretolamna are on top and Otodus on the bottom of the first pic, as you are looking at your computer screen. Furthermore, on the same pic, the tips of the Cretolamna teeth point down and the tips of the Otodus point up.

All of the teeth are from the Paleocene Aquia formation along the Potomac River in Charles County, Maryland.

Thanks, Ron! That helps immensely. The large group of teeth is far more useful that the few line-drawings that Kent offers. Frankly, I don't think that Kent's drawings are as useful as I'd expected now that I see your collection.

Still, the question remains, Is there a reliable way to identify the small, lateral teeth for those of us who don't have a large assemblage of these teeth? Perhaps, we'll have to make up our own keys to ID these teeth from Morocco.

I'm going to re-visit my own sorting of Moroccan teeth. Just while reading this thread, I've discovered the my "B" tooth from the trio I posted actually fits well with two teeth that I couldn't ID in an earlier thread. I thought these teeth must be Cretodus, but I was disabused of that notion in discussing it with Northern Sharks. Maybe they are actually some subspecies of Cretalamna appendiculata.

Any other thoughts?

[Harry Pristis]

Thanks, Ron! That helps immensely. The large group of teeth is far more useful that the few line-drawings that Kent offers. Frankly, I don't think that Kent's drawings are as useful as I'd expected now that I see your collection.

Still, the question remains, Is there a reliable way to identify the small, lateral teeth for those of us who don't have a large assemblage of these teeth? Perhaps, we'll have to make up our own keys to ID these teeth from Morocco.

I'm going to re-visit my own sorting of Moroccan teeth. Just while reading this thread, I've discovered the my "B" tooth from the trio I posted actually fits well with two teeth that I couldn't ID in an earlier thread. I thought these teeth must be Cretodus, but I was disabused of that notion in discussing it with Northern Sharks. Maybe they are actually some subspecies of Cretalamna appendiculata.

Any other thoughts?

After looking again at these few small teeth (five altogether), it occurs to me that the real differences between them is the root shape. . . not the crown, not the "bridge," not the cusplets.

Another tour of Elasmo.com revealed that there are two distinct tooth sets -- one Eocene, one Palaeocene -- presented for Otodus obliquus from North Africa. The two sets of teeth appear to have different root conformation. The Palaeocene teeth appear to have a more "boxy" root, while the Eocene teeth appear to have the more flowing, rounded root form.

This is a subjective judgement, and it would be helpful if some readers here would opine on this observation. Go to Elasmo.com => "genera" (in the obscure tool-bar at the top of the page) => "palaeogene" => "Otodus" => (scroll down to) tooth set => "Palaeocene"

Are all five of the teeth I have posted actually Otodus obliquus, with only a root morphology to distinguish between them?

[alopias]

here is other otodus from Morocco

[Harry Pristis]

here is other otodus from Morocco

When you say "other Otodus," do you mean the Eocene form with the flowing, rounded root? Do you see two root forms in this species from Morocco?

Quand vous dites le " l'autre Otodus, " voulez-vous dire la forme d'Eocene avec l'écoulement, racine arrondie ? Voyez-vous deux formes de racine en cela des espèces du Maroc ?

[alopias]

the Eocene form is Otodus subserratus Ypressian

[Harry Pristis]

the Eocene form is Otodus subserratus Ypressian

Thank you for the input, Alopias. Here's what Elasmo.com says about "subserratus."

Otodus subserratus (Fig. 1) is a species based on a single specimen, supposedly from the Early Eocene London Clay of Sheppey, UK. Unfortunately, the holotype, from its preservation and morphology is not from the London Clay of Sheppey, and not of this lineage. It is a tooth of Cosmopolitodus*, probably from the Belgian Miocene (see Woodward, 1889; Priem, 1912). Thus the name subserratus, at whatever rank, should not be used in the Otodus-Carcharocles lineage.

Sooo . . . you can see the complication involved in distinguishing Palaeocene and Eocene Otodus from Morocco based on that name. I think we are looking for something other than a true species.

[non-remanié]

I would say all 5 are otodus if the teeth are TRULY paleocene/eocene. If they were Cretaceous, I think one or more of the teeth would be easily named Cretolamna appendiculata pachyriza instead. I think that is the specific subspecies form of Cretolamna that is really providing the problem here. As Paleoron illustrated with his collection (at least at this one particular site in Md) it is fairly easy to tell Otodus from Cretolamna.

Thanks, Ron! That helps immensely. The large group of teeth is far more useful that the few line-drawings that Kent offers. Frankly, I don't think that Kent's drawings are as useful as I'd expected now that I see your collection.

Still, the question remains, Is there a reliable way to identify the small, lateral teeth for those of us who don't have a large assemblage of these teeth? Perhaps, we'll have to make up our own keys to ID these teeth from Morocco.

I'm going to re-visit my own sorting of Moroccan teeth. Just while reading this thread, I've discovered the my "B" tooth from the trio I posted actually fits well with two teeth that I couldn't ID in an earlier thread. I thought these teeth must be Cretodus, but I was disabused of that notion in discussing it with Northern Sharks. Maybe they are actually some subspecies of Cretalamna appendiculata.

Any other thoughts?

[jbstedman]

I would say all 5 are otodus if the teeth are TRULY paleocene/eocene. If they were Cretaceous, I think one or more of the teeth would be easily named Cretolamna appendiculata pachyriza instead. I think that is the specific subspecies form of Cretolamna that is really providing the problem here. As Paleoron illustrated with his collection (at least at this one particular site in Md) it is fairly easy to tell Otodus from Cretolamna.

I found Paleoron's pictures to be very helpful, but, I don't think they were intended to show a random sample from his collection of possible Otodus or Cretalamna contenders from this Md. site. I think that contributes greatly to toothpuller's conclusion that, for these teeth, it's "fairly easy to tell Otodus from Cretalamna." At a minimum, I feel that some posterior teeth are likely to still pose a real challenge.

As to Harry's question about the two sets of associated Otodus teeth on elasmo.com (one Paleocene and one Eocene), what really jumped out at me was that the cusplets seemed very different between the two sets. More robust and likely to curve outward in the Paleocene. I would agree that there's a "boxiness" to the Paleocene set, not showing up in the Eocene set.

[Harry Pristis]

I found Paleoron's pictures to be very helpful, but, I don't think they were intended to show a random sample from his collection of possible Otodus or Cretalamna contenders from this Md. site. I think that contributes greatly to toothpuller's conclusion that, for these teeth, it's "fairly easy to tell Otodus from Cretalamna." At a minimum, I feel that some posterior teeth are likely to still pose a real challenge.

As to Harry's question about the two sets of associated Otodus teeth on elasmo.com (one Paleocene and one Eocene), what really jumped out at me was that the cusplets seemed very different between the two sets. More robust and likely to curve outward in the Paleocene. I would agree that there's a "boxiness" to the Paleocene set, not showing up in the Eocene set.

I'm glad someone else sees some difference between the two sets of Otodus teeth on Elasmo.com . . . my eyes are grown bleary from studying these details.

Speaking of details . . .

I believe that these three teeth, which I posted earlier, are from Cretalamna appendiculata pachyrhiza. I have come to that conclusion after a suggestion from "Toothpuller" and some research on the Internet.

The features that my conclusion is based upon are the strongly divergent cusplets and the more prominent lingual protuberances (than on other Cretalamna teeth).

Although not mentioned in Kent, C. a. pachyrhiza apparently is known from Morocco. I was easily able to find examples on the Internet.

[tracer]

i had alluded earlier to my newbie's confusion regarding naming conventions and how "species" are determined simply from tooth characteristics of extinct organisms. i read up a little on elasmo and found a lot of qualified terms and tentative statements, which is fine with me, but i also read things about standing up a new species name whenever something comes along that doesn't shoehorn into an existing category of curves, points, serrations, etc. there also seem to be such concepts as "chronospecies" differentiated exclusively by time, and morphospecies, differentiated exclusively by seeming to possess visible characteristics between those of two previously "erected" species. to me, and remember i don't know what i'm talking about, this seems as if there are two wildly differing concepts of species. one for modern animals, defined as being their ability to get together and carry on the bloodline, and then the concept for extinct things seems to be - do the tiny parts remaining of them look really, really similar?

could somebody please elaborate on this? i probably need correction in that i'm starting to really feel like some of this stuff is just a house of cards built by people who liked naming things. and i don't have a problem with naming things, but i don't understand if the definition of what a species is has been eliminated for the purpose of naming fossils.

i'm concerned about this because, with the amount of cosmetic dental work people are having nowadays, future scientists are probably going to end up thinking there was a "cambrian explosion" type event for homo subsapiens veneerensis and other variants of pulchradontid hominids.

[Auspex]

...this seems as if there are two wildly differing concepts of species. one for modern animals, defined as being their ability to get together and carry on the bloodline, and then the concept for extinct things seems to be - do the tiny parts remaining of them look really, really similar?

Naming things is an obsessive/compulsive imperitive among humans; it is how we seek to define (and thus understand) the world in which we live. The concept of a species is just that, and some things are more obviously differentiated than others. When the defining gets tough, the criteria can morph to accommodate the facts. It is a process, and it is not limited to extinct organisms; Google "Traill's Flycatcher" for a good example.

[jbstedman]

Naming things is an obsessive/compulsive imperitive among humans; it is how we seek to define (and thus understand) the world in which we live. The concept of a species is just that, and some things are more obviously differentiated than others. When the defining gets tough, the criteria can morph to accommodate the facts. It is a process, and it is not limited to extinct organisms; Google "Traill's Flycatcher" for a good example.

Love it. The first site that turned up for me has the following (poorly punctuated) statement: "Traill's Flycatcher is not an actual species it is the name given to a flycatcher when it can not be determined whether it is an alder or willow flycatcher. The two species are quite similar and can usually only be distinguished by their songs."

[tracer]

it probably ought to be called "a-guy(maybe)-named-something-like-'thraill's-common-appearing-insect-apprehender-by-some-means"

[Carl O'Cles]

QUOTE (Auspex @ Dec 3 2008, 11:19 PM)

Well considered, Carl; can you correlate a similar trend in the size of the prey base? "Follow the food"...

There's not much in the way of boney fish remains to be found, a few teeth, phargenial plates, and the occasional vert, but there is a lot of ray material at the site. Living sharks like to eat rays so it's a good bet rays were tasty back then also.

PaleoRon is right here in that it is hard to follow this trend because of the few fish remains. I can say for certain that the otodus here wear eating rays. Attached is an image of a ray plate that I collected from a fallen chunk of the cliff. The straight end was what was exposed so the damaged area was embedded in the clay. Since it was in the clay we know that it had to have happened before fossilization and based on the type of damage and what species were alive back then one can only deduce that it was an otodus that sheared this plate. As for other animals that the otodus could have been chomping on one can only imagine that with it being the super predator of the time it ate what ever it wanted. But beyond that although I have yet to find any croc or turtle remains with predation marks I am confident that they wear eating them. The reason I say this is that there are large amounts of larger otodus at this site that either have massively dinged tips or are severely damaged and the only animals at the time that could cause this would have been hard turtle's or scute'ed croc's. You can also see this trend in teeth from morocco where there are a ton of them with dinged tips. The even cooler thing about Moroccan teeth is that there are so many of them coming out and with this high sampling of teeth you can see that there are a ton of pathological teeth. When I look at this high number of pathy's I can only figure that the damage to the teeth and their files could have only been caused by chomping on hard items such as crocs and turtles because lets face it I know of no large armored fish from the time and of no other animals with hard bones such as marine mammals to cause this.

[Harry Pristis]

. . . When I look at this high number of pathy's I can only figure that the damage to the teeth and their files could have only been caused by chomping on hard items such as crocs and turtles because lets face it I know of no large armored fish from the time and of no other animals with hard bones such as marine mammals to cause this.

I was impressed then the Aussie TV guy was killed by a stingray a couple of years ago. I suddenly understood the purpose of the spine on the tail of those rays. It's not to kill snorkelers or to wound waders in the calf; the spines are a serious defense against predators. And the big predators on rays? . . . sharks.

There's an interesting short article in the DISCOVER magazine (Jan. 2009) about collapsing chains of multi-cellular life forms and "The Rise of the Slime." Among other things, it mentions,

The Chesapeake Bay is a prominent victim of this devilish synergy. Giant oyster reefs there have long since been harvested, as have the menhaden. Scallop and clam fisheries have also collapsed, in part because the overfishing of sharks has set off a population explosion of rays, which eat mollusks.

I posted this image elsewhere recently, but it's worth re-visiting when evaluating pathological shark teeth.

[non-remanié]

True, it wasn't a random sample. It can be extremely difficult to identify ANY extreme posterior teeth though. It doesn't help when 95% of the teeth from this site are quite beach worn and rounded and cretolamna is fairly uncommon to begin with. I think the differences would be more noticeable if you saw pristine examples. Sometimes you have to just stop playing the game when the percent of rounding vs. definable features gets fairly high. One overly simple rule that I go by is that the Cretolamna blades have more of a slant than a curve in Otodus, if that makes sense.

I found Paleoron's pictures to be very helpful, but, I don't think they were intended to show a random sample from his collection of possible Otodus or Cretalamna contenders from this Md. site. I think that contributes greatly to toothpuller's conclusion that, for these teeth, it's "fairly easy to tell Otodus from Cretalamna." At a minimum, I feel that some posterior teeth are likely to still pose a real challenge.

As to Harry's question about the two sets of associated Otodus teeth on elasmo.com (one Paleocene and one Eocene), what really jumped out at me was that the cusplets seemed very different between the two sets. More robust and likely to curve outward in the Paleocene. I would agree that there's a "boxiness" to the Paleocene set, not showing up in the Eocene set.

[jbstedman]

True, it wasn't a random sample. It can be extremely difficult to identify ANY extreme posterior teeth though. It doesn't help when 95% of the teeth from this site are quite beach worn and rounded and cretolamna is fairly uncommon to begin with. I think the differences would be more noticeable if you saw pristine examples. Sometimes you have to just stop playing the game when the percent of rounding vs. definable features gets fairly high. One overly simple rule that I go by is that the Cretolamna blades have more of a slant than a curve in Otodus, if that makes sense.

In the final analysis, not sure a random sample would have made too much difference since, as you and Paleoron have noted, the chances are great that, at this Md. site, we'll find Otodus, not Cretalamna. I think you're right about extreme posterior teeth being a black hole regardless.

I understand the slant (Cretalamna) versus curve (Otodus) distinction and it helps. Thanks.

[Harry Pristis]

Do you suppose that this Otodus obliquus tooth is pathological (labio-lingual curve)? Is it a lateral tooth or is it a posterior tooth?

I'm calling this one "probably Eocene" (as opposed to Paleocene) based on the shape of the root, as discussed earlier in this thread.

[Northern Sharks]

Harry: Based on the 2 dentition photos on Elasmo, yours seems to look more like an upper, posterior, Paleocene Otodus tooth. The Paleocene teeth seem to have more curvature and wider blades, while the Eocene teeth look to be straighter but angled back with narrower blades.

[non-remanié]

Maybe its just me, but I don't think the protuberance is any more pronounced than the differences in Otodus root shapes we have already seen. Therefore, I see no reason not to label them Otodus instead. Also, this group exhibits a difference in root shape akin to what we have already seen in Otodus if you want to use that as a guide. The problem is that you are so quick to adjust the stratigraphic information label. This means you really have no clue what age they are. I think this is a systemic problem with Moroccan teeth, everything gets mixed together, especially teeth that look like Otodus and/or are larger. If you really knew the teeth to be early paleocene or late cretaceous then you might be justified in your conclusion, but you obviously don't know that. I have no idea how to tell them apart myself, but I think the key would be getting a supply of early paleocene teeth from Morocco that you are positive has the correct stratigraphic information attached. Or possibly the Arambourg text on the Moroccan fauna would help. If you do have the Arambourg text, then perhaps you could scan the C. appendiculata pachyrhiza description even though its in french. (I believe the description is in Arambourg) We could OCR it and use a translator. I am curious myself.

I'm glad someone else sees some difference between the two sets of Otodus teeth on Elasmo.com . . . my eyes are grown bleary from studying these details.

Speaking of details . . .

I believe that these three teeth, which I posted earlier, are from Cretalamna appendiculata pachyrhiza. I have come to that conclusion after a suggestion from "Toothpuller" and some research on the Internet.

The features that my conclusion is based upon are the strongly divergent cusplets and the more prominent lingual protuberances (than on other Cretalamna teeth).

Although not mentioned in Kent, C. a. pachyrhiza apparently is known from Morocco. I was easily able to find examples on the Internet.

[Harry Pristis]

<snip> The problem is that you are so quick to adjust the stratigraphic information label. This means you really have no clue what age they are. I think this is a systemic problem with Moroccan teeth, everything gets mixed together, especially teeth that look like Otodus and/or are larger. If you really knew the teeth to be early paleocene or late cretaceous then you might be justified in your conclusion, but you obviously don't know that. I have no idea how to tell them apart myself, but I think the key would be getting a supply of early paleocene teeth from Morocco that you are positive has the correct stratigraphic information attached. <snip>

It's not just my problem, it's everyone's problem who'd like to identify these teeth.

The biochronology is the most flexible factor in the identification. Morphology rules!

I've been there in the village fossil-broker's cobblestone warehouse. I know how these teeth were collected, sorted, and sold. A shark tooth is a shark tooth in Khouribga.

I plucked these teeth from an accumulation of teeth that included (no doubt) Ypresian Otodus as well as Maastrichtian Globidens teeth. It's a waste of time to wish for stratigraphic data. So, we have to go with what we have . . . morphology. Arambourg's illustrations might help with the morphology.

I know we've discussed this morphology challenge before, perhaps in another thread. Shark tooth collectors should have no illusions about Moroccan teeth -- the only reliable way to date them is to know what species they represent. Collectors who don't want to take the pains (and it is a pain) to familiarize themselves with the subtleties of tooth morphology can reliably say about their teeth only that they are between 52 and 68 million years old (or so).

For decades (literally), that's how I treated these Moroccan teeth -- all Otodus, all the time! There is enough information available now to start making some distinctions between some of these attractive teeth.

This thread and others is intended to describe what we think we see in the Moroccan shark teeth that we are trying to categorize. Some of these characteristics that are discussed may be difficult to appreciate through an image or two. Some characteristics may not rise to the level of consistently diagnostic, some may be an illusion. But, that's why we discuss them -- to find what's useful and what's not.

We may never achieve a consensus on these diagnostic features, but each of us is educating himself on the range of possibilities here. I find that worthwhile.

[non-remanié]

Well put Harry, but I don't think morphology is enough in the shark tooth world without dentition studies which are often not available at all. And I don't know what this wealth of data on C. appendiculata pachyrhiza is besides some other wbesites selling them as such. Who is to say they know anything more than you or have a more pristine source with good stratigraphic information? A couple might, but I am doubtful that most retailers do for the same reasons as you allocuted.

What about the root differences in your group? Wouldn't it make more sense if those root differences which we have informally noticed in the Otodus point to your group being small Otodus teeth from both Eocene and Paleocene, rather than the pachyrhiza? Now, I don't really believe that root shape thing is really accurate to begin with, but if youre going to use it at all shouldnt you be consistent and include these teeth as well? If you want to get super crazy what about the color differences? This could be a legitimate difference in preservation of the different strata rather than just an consequence of weathering. Maybe someone who has seen a lot of Moroccan Otodus can chime in on that? Are the dark orange otodus more likely to be Paleocene, or at least possess the paleocene root and blade shape we have noted?

It's not just my problem, it's everyone's problem who'd like to identify these teeth.

The biochronology is the most flexible factor in the identification. Morphology rules!

I've been there in the village fossil-broker's cobblestone warehouse. I know how these teeth were collected, sorted, and sold. A shark tooth is a shark tooth in Khouribga.

I plucked these teeth from an accumulation of teeth that included (no doubt) Ypresian Otodus as well as Maastrichtian Globidens teeth. It's a waste of time to wish for stratigraphic data. So, we have to go with what we have . . . morphology. Arambourg's illustrations might help with the morphology.

I know we've discussed this morphology challenge before, perhaps in another thread. Shark tooth collectors should have no illusions about Moroccan teeth -- the only reliable way to date them is to know what species they represent. Collectors who don't want to take the pains (and it is a pain) to familiarize themselves with the subtleties of tooth morphology can reliably say about their teeth only that they are between 52 and 68 million years old (or so).

For decades (literally), that's how I treated these Moroccan teeth -- all Otodus, all the time! There is enough information available now to start making some distinctions between some of these attractive teeth.

This thread and others is intended to describe what we think we see in the Moroccan shark teeth that we are trying to categorize. Some of these characteristics that are discussed may be difficult to appreciate through an image or two. Some characteristics may not rise to the level of consistently diagnostic, some may be an illusion. But, that's why we discuss them -- to find what's useful and what's not.

We may never achieve a consensus on these diagnostic features, but each of us is educating himself on the range of possibilities here. I find that worthwhile.

[Harry Pristis]

Well put Harry, but I don't think morphology is enough in the shark tooth world without dentition studies which are often not available at all. And I don't know what this wealth of data on C. appendiculata pachyrhiza is besides some other wbesites selling them as such. Who is to say they know anything more than you or have a more pristine source with good stratigraphic information? A couple might, but I am doubtful that most retailers do for the same reasons as you allocuted.

What about the root differences in your group? Wouldn't it make more sense if those root differences which we have informally noticed in the Otodus point to your group being small Otodus teeth from both Eocene and Paleocene, rather than the pachyrhiza? Now, I don't really believe that root shape thing is really accurate to begin with, but if youre going to use it at all shouldnt you be consistent and include these teeth as well?

If you want to get super crazy what about the color differences? This could be a legitimate difference in preservation of the different strata rather than just an consequence of weathering. Maybe someone who has seen a lot of Moroccan Otodus can chime in on that? Are the dark orange otodus more likely to be Paleocene, or at least possess the paleocene root and blade shape we have noted?

When I was dealing fossils actively, I felt enormous pressure to "get it right" when it came to identifying something I sold. I don't doubt that active purveyors of Moroccan shark teeth are feeling the same pressure. You can't stay in business if your knowledge of such things is in doubt. Actually, I never thought to look at a commercial site for an ID of the pachyrhiza teeth. I did find an image of associated teeth from Morocco posted on a French web-site. I didn't save it because I didn't think there was much interest.

I can't rule out completely that my three examples aren't prime examples of baby Paleocene Otodus teeth. With the few available to me, and with them in hand (versus in an image), I think they are not Otodus. This is my theory, which explains my observations and fits reasonably well the few published facts I can find. When there are new observations and new facts, my theory will evolve.

I'll stick to being moderately crazy, and will leave getting "super crazy" to others. Color differences in the teeth as an indicator of age is a red herring which can only distract from the questions at hand.

I understand your skepticism about diagnostic root shapes. I spent a lot of time comparing teeth before I saw much difference between them. Would that we had more information to work with! Alas, we have to work with what we have, and Kent and other workers put considerable focus on root shapes in their diagnoses.

You know as well I the weaknesses and pitfalls of fossil shark taxonomy; nevertheless, I don't hear anyone saying, "It's hopeless . . . I give up! They're all just Cretaceous - Eocene Lamniforms, and that's all we can say for sure." I continue to believe that these teeth can be identified to some further degree.

it is those who know little, and not those who know much, who so positively assert that

this or that problem will never be solved by science. - Charles Darwin

[non-remanié]

Okay. I dont think anyone really sees it but you, even with your most excellent images, but I guess you see something that you think is significant. And the teeth are in your hands so you have the best view, so maybe there is something to it. I really don't think you should even be attempting it without having more sources for similar species than just the jumbled mess of Moroccan teeth. But If you are correct it would probably mean that elasmo should also list pachyrhiza in the Aquia page of Md/Va and that some of Paleoron's fit this group more than Otodus. And by the way Kent's pachyrhiza is pretty small compared to yours. And it stinks theres only an anterior with much more splayed cusps than any we have seen so far.

What percentage of random small teeth of this type would you say would you call pachyrhiza using your examples? I looked through a random bag of ~25 small otodus teeth and the vast majority had cusps as divergent as your few examples. The ones that didnt were mostly anteriors. I would say there is a serious problem in your theory if most of these teeth are ending up in the pachyrhiza bag rather than small Otodus.

I understand your skepticism about diagnostic root shapes. I spent a lot of time comparing teeth before I saw much difference between them. Would that we had more information to work with! Alas, we have to work with what we have, and Kent and other workers put considerable focus on root shapes in their diagnoses.

[/indent]

[Harry Pristis]

Okay. I dont think anyone really sees it but you, even with your most excellent images, but I guess you see something that you think is significant. And the teeth are in your hands so you have the best view, so maybe there is something to it.

I really don't think you should even be attempting it without having more sources for similar species than just the jumbled mess of Moroccan teeth. But If you are correct it would probably mean that elasmo should also list pachyrhiza in the Aquia page of Md/Va and that some of Paleoron's fit this group more than Otodus. And by the way Kent's pachyrhiza is pretty small compared to yours. And it stinks theres only an anterior with much more splayed cusps than any we have seen so far.

What percentage of random small teeth of this type would you say would you call pachyrhiza using your examples? I looked through a random bag of ~25 small otodus teeth and the vast majority had cusps as divergent as your few examples. The ones that didnt were mostly anteriors. I would say there is a serious problem in your theory if most of these teeth are ending up in the pachyrhiza bag rather than small Otodus.

You say now that no one but me sees the distinctiveness of the three teeth that I have labeled "pachyrhiza." I respectfully point to your earlier post about these teeth:

I would say all 5 are otodus if the teeth are TRULY paleocene/eocene. If they were Cretaceous, I think one or more of the teeth would be easily named Cretolamna appendiculata pachyriza instead. [emphasis added] I think that is the specific subspecies form of Cretolamna that is really providing the problem here. As Paleoron illustrated with his collection (at least at this one particular site in Md) it is fairly easy to tell Otodus from Cretolamna.

Your judgement about some of the teeth being "pachyriza" depended then on their being Cretaceous in age (although Kent cites reports of Cretolamna appendiculata pachyrhiza from the Maastrichtian and Early Paleocene of Europe and North America).

Since we've already agreed that the actual age of the teeth is unknowable, I choose to rely on what your eyes were telling you when you made this December 7 post.

I have only these three teeth that I would call C. a. pachyrhiza. I will certainly be on the lookout for others.