Northern Sharks

Finally

151 posts in this topic

Harry, thanks for the help. I have taken your advice and put a new topic in the fossil id forum, but I figured you might be the most qualified to ID it anyway so just posted it here to begin with :) Since you thought is was Equus rather than rhino or tapir I have opened it up for more opinions. Equus would be quite interesting because there has only been one report of Miocene Equus from NJ, and that is listed as a tooth of Anchitherium. My first guess was actually Equus also, but most likely that had a lot to do with the fact that there were many more Equus astragalus on the internet and in my available literature than rhino or tapir. A couple of semi-experts didn't think it was Equus and one of them saw it in person, but none of them were positive on an ID. But I do value your opinion and hopefully I can get some more help!!

Regarding the teeth... I don't even think BTF would necessarily call them Parotodus. To me they seem to have significant differences to all the Eocene Parotodus we have looked at and the only commonality are those rounded cusps on SOME. Even one of the Moroccan ones on BTF has sharp cusps so that really seems to not be too significant as a diagnostic. Therefore, I don't really see any reason to assign them to Parotodus more so than Cretalamna from our information. It definitely is somewhat subjective just comparing pictures on the net and not having the teeth in hand, but that is my opinion. I just wouldn't want to buy something labelled as Parotodus sp. or even Parotodus-like when these were the only criteria used in making that call.

And that sure was an awesome bear-dog tooth you posted! It agrees with what I have seen regarding the enamel. That definitely rules out land mammal I think, even though I thought it was a long shot to begin with. (wishful thinking on my part)

-steve

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Harry why don't you just email the BTF guy and ask for his opinion and/or if he could point you to a resource that has information on Moroccan Eocene Parotodus? I did a little more research and maybe Parotodus is the best fit right now but it still seems that yours may have a few differences. At worst he will just ignore your email :)

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I have a moroccan that was found in the middle of bare dfw

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I've only read the first couple of pages and their I saw that some people still stick to using CretOlamna instead of CretAlamna.

I'll quote something from www.somniosus.be

In the section "Maastrictian", klick on "Sharks and rays".

At the bottom of the page you'll find the following:

"** Cretalamna GLICKMAN 1958 is repeatedly misspelled as Cretolamna in the literature. Glickman, L.S. 1958, Rates of Evolution in Lamnoid Sharks. Report of the USSR Academy of Sciences 1958, volume 123 (3), p. 570"

The species has been named for the first time by Glickman, it was called Cretalamna, so I believe that this is the only correct spelling and not unorthodox at all;-).

Greetings

EDIT: well, this has been said on the previous page so my comment may be ignored. I'll just leave it here for "educational purposes" :-)

Edited by Hieronymus

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Has anyone gone on record as supporting this evolutionary scheme?

C. appendiculata

\__Otodontidae

\__Issuridae

\__Paleocarcharodon

We can find both Otodus Obliqus, Otodus Subserratus and Cretolamna Appendiculata in the london clay isle of sheppey UK and the site has only 4my from one end to the other ageing at about 48-52mya, it was first thought that cretolamna became extinct and did not survive the extinction marking the end of the cretaceous however sheppey shows clearly that cretolamna survived into the Eocene. Are we therefore to believe that these two sharks swam side by side or was there a transitional period around that time. It seems that most of the otodus are transitional at sheppey as they have lost those true obliqus traits that are evident in the earlier Otodus from Tankerton. So the question has to be what become of Cretolamna at that point onwards. I am aware that Paleocarcharodon had already come to be but dont think Issuridea were around at that point so it is is possible that the surviving Cretolamna evolved into Isurus later on.

We can also find Isurolamna affinis on sheppey which are very simular to cretolamna, Is it possible that these could be from the same branch also. Please excuse me if this sounds stupid as I am not that farmiliar with sharks teeth. But based on teeth this would seem the obvious answer to me but as I say im just a mere amatuer.

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Nice Find!!...

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Nice Find!!...

What are you talking about? What's a "Nice Find!" in this thread? Are you merely posting to get to 50 posts? It sounds like you haven't read the thread.

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Santa came early here in the north country. I've been after one of these for a while and I finally got one in the mail today. It's an early, transitional form, Palaeocarcharodon orientalis. Very coarse serrations near the root fading to almost smooth at the tip. One root tip was glued back on as these teeth are very prone to damage, but I can ignore that because it's almost 2 inches long, and they don't get much bigger than that.

Last year, I went through old topics but missed this one (wasn't aboard when all the fur was flying) - perhaps because of the nondescript thread title. While some here dislike having "zombies" revived, I love it, but I won't just say "nice tooth," though it is a good example of the transition from Cretalamna to Palaeocarcharodon. Teeth like that one come out of the earliest Paleocene layers (not the Late Cretaceous).

Apparently, the extinction of nearly all large sharks at the end of the Cretaceous left open the apex predator for the small survivors to move into. Palaeocarcharodon and Otodus were the big boys by the Late Paleocene but for some reason the former died out just before the end of the Paleocene - perhaps due to climatic cooling just before a warming trend that started at the end of the Paleocene. The only other large Cretaceous survivor was Notidanodon (perhaps just one or two large species of Notorynchus) but it frequented deepwater so it did not compete directly with the two surface-dwellers. Notidanodon also died out near/at the end of the Paleocene - perhaps gassed by massive methane releases from the ocean bottom.

Meanwhile, Cretalamna continued to make a living and may have branched off into Isurolamna by the Mid-Late Paleocene while Cretalamna continued into the Early Eocene.

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The way I've been understanding has early Cretolamna evolving into 3 branches: the Otodus lineage, the makos with I. praecursor and the dead end Palaeocarcharodon. Joe Cocke is a collector and worked in the Natural History Museum of L.A. County for 33 yrs as taken from the back of his book.

Joe Cocke is a well-respected shark tooth collector out here in California who could have written something more technical and expansive but he chose to make that book more accessible to beginners while also illustrating a decent representation of the diversity of fossil sharks. He's been collecting sharks since at least the 60's and is someone I go to when I have a question - a great guy to talk to, knowledgeable and experienced yet modest. I met him at the Costa Mesa show during the 90's.

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http://www.elasmo.com/frameMe.html?file=he...topics-alt.html

I don't know if the link will work this time or not, but Bill Heim at Elasmo.com seems to be in favor of this family tree. Also, while Cretolamna looks like the forerunner of the giant white sharks, it may or may not be C. appediculata. One person states on eurolasmo.com that it could be C.gunsoni (Siverson, 1996) which I had never heard of. As you say Harry, it is murky. I'd love to have more time to search for things like this, but I have 3 young kids and my spare time is limited.

The key to finding out how the lineages actually branched off is the Paleocene. It was a short epoch with rather few remaining deposits that would yield shark remains. North Africa and the Middle East offers a remarkably generous geology where sedimentation was near-continous from the Late Campanian through Early Eocene with a little Middle Eocene on top. While much was eroded away the remaining phosphate basins are rich in shark-bearing layers but even with all that and the marine units of the Atlantic Coastal Plain and Gulf Coast, some important transitions may never get illuminated if they occurred outside those areas. During the Paleocene Cretolamna apparently engendered forms either directly or through intermediates that became Isurolamna, Isurus, Otodus, Palaeocarcharodon, Lamna, Alopias, Carcharocles, and Carcharodon - in other words many of the best-known lamniform groups of the Cenozoic.

Where I would disagree with the elasmo.com chart is that hastalis led to escheri as the latter looks more like desori than hastalis. Isurolamna could have evolved directly from Cretalamna appendiculata but there could have been at least one species/tooth form in between. Isurus oxyrinchus could have evolved directly from a species of Isurolamna though there are no good candidates known at the moment. All the mako/mako-like teeth of the Middle-Late Eocene look like praecursor though Isurolamna has some sand tiger-like teeth during the Middle Eocene and some sand tigers (Jaekelotodus) have some more robust tooth positions showing a good degree of variation. I've seen only a tiny fraction of all the teeth that have come out of the Early Eocene-Oligocene of Kazakhstan but shark evolution seems to have gone wild over there during that time.

Yes, there is C. gunsoni and "Cretolamna" schoutedeni, a Paleocene species, which I have also seen listed as Isurus schoutedeni. For a while, I was on the lookout for even just a drawing of this species. It intrigued me as it seemed to be the earliest mako. Several weeks ago, I received two lower anterior teeth in a trade ID'ed as Cretalamna schoutedeni and they do closely resemble C appendiculata lower anteriors though somewhat larger. These teeth came from a Late Paleocene layer so the species may not range back far enough to be relevant to this discussion.

I tend to be doubtful of new species based on somewhat few teeth that could be just a regional variation of an established species but C. gunsoni does appear to be valid (anterior teeth with almost sand tiger-like lateral cusplets - more hook-like than appendiculata). For anyone wanting the title and journal for Siverson (1996):

Siverson, M. 1996.

Lamniform Sharks of the Mid Cretaceous Alinga Formation and Beedagong Claystone, Western Australia. Palaeontology. Vol. 39. Part 4, pp. 813-849.

Edited by siteseer

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This is a pinned thread, Jess . . . don't think of it as a zombie thread. I learned quite a bit from this thread, and I'm glad to see your input.

All of these subtle differences in lamniform teeth cry out for images! At least let us see the Cretalamna schoutedeni you mentioned. Comparison (side-by-side) images are always instructive, too.

Edited by Harry Pristis

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This is a pinned thread, Jess . . . don't think of it as a zombie thread. I learned quite a bit from this thread, and I'm glad to see your input.

All of these subtle differences in lamnaform teeth cry out for images! At least let us see the Cretalamna schoutedeni you mentioned. Comparison (side-by-side) images are always instructive, too.

Harry,

I will put those teeth at the front of the line of fossils I want to photograph for the forum. I will go through some stuff for comparative material as well, other Cretalamna lowers in particular.

Of course, in many taxonomic discussions the "lumping" and "splitting" camps have led to multiple interpretations especially in the world of fossil sharks and rays where names have been often based on just teeth and sometimes very few and/or rather poorly-preserved teeth.

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Well, Cenomanian-age is just a guess. I do not have any collecting data on these teeth, so I'm hoping that the age can be deduced by the species present. These could be Maastrichtian as easily as Cenomanian, though I don't know of any significant Maastrichtian non-phosphate fossils from Morocco. But, that lack of knowledge is not definitive, just speculative.

This is a big problem with Moroccan fossils. The older paleontology papers are in French, for the most part. The diggers don't know any paleontology, and the brokers are just interested in accumulating and selling curios. (This is changing slowly, I think, but it is market-driven.) I've been to Erfoud and elsewhere, and I've seen it for myself.

Mostly, the average collector has to reconstruct as best he can some sort of paleontological framework for a Moroccan fossil. This is the reason that these teeth of mine have been sitting here in a zip-lock bag for years, and not in my drawer.

------Harry Pristis

Harry,

You've identified another part of the problem within this discussion. In most cases, when you show teeth from Morocco, no matter how rare and beautiful, you are showing specimens that are largely useless because you don't have any real locality data. If it's a Squalicorax pristodontus, you can say it's Late Cretaceous because you recognize that species as a Campanian-Maastrichtian shark but Cretalamna appendiculata crossed the K/T boundary along with a few other forms. Other taxa appeared in the Paleocene and survived into the Eocene while others lived only within the Paleocene or only within the Eocene.

As you noted, the older papers on the geology of the Moroccan phosphates, Arambourg (1952) being the best-known and most ambitious, were written in French and remain largely untranslated other than excerpts. Those works have been reviewed and revised, again largely in French (e.g. Noubhani and Cappetta, 1997) but the figures provide a good overview for all researchers and collectors of any language.

The bulk of the Moroccan shark teeth that end up at fossil shows and flea markets come from one of five phosphate basins. That one is called the Ouled Abdoun. In that basin, most of the teeth come from a phosphate mine at Khouribga but some come from Oued Zem. French geologists have been working in North Africa since at least the 1930's. Since the 1960's, one paleontologist has devoted much of his professional life to the sharks and rays of Morocco, Henri Cappetta. With the help of many co-authors and collectors, he has been working on understanding the selachian faunas in each bed from the Early Maastrichtian (about 70 million years ago), the base of the phosphate layers, to the Middle Eocene (about 45-50 million years go) when phosphate deposition ended. The beds of the Maastrictian and Ypresian (Early Eocene, 50-55 million years ago) appear to be the most productive but fossils of other ages in between are dumped into the same containers so dealers and collectors have no way to know the bed of origin as you noted and saw in person.

However, it is possible to get samples from collectors who know the geology and have been able to dig on their own or have accompanied paleontologists on digs. When you have teeth with labels that provide the bed number, that's the starting point to understanding not only what comes out of Morocco but also what time it represents. In Noubhani and Cappetta (1997) figures on page 10, 11, 12, 13, and 14 provide a decent overview of the phosphate basins, general localities, and generalized stratigraphic columns (because no particular site provides a view of the whole column which can be constructed from the sum of the sites) with a close-up of one basin's main collecting sites.

I have been lucky to meet collectors who have hunted the phosphates themselves or who have traded directly with them so I have some specimens with exact locality data. I don't have a full understanding of the sharks and rays of Morocco since I don't have samples of all the taxa, or even most of them, from each bed, but I am getting an idea of the chronologic range of certain species, and that helps whenever I get into one of these discussions.

Arambourg, C. 1952.

Les vertebres fossiles des gisements de phosphates (Maroc-Algerie-Tunisie). Serv. Geol. Maroc, Notes et Mem., 92: 1-372.

[Anyone who collects sharks and rays should have this. You should be able to find it at a university library or get it through inter-library loan at your local public library.]

Noubhani, A. and H. Cappetta. 1997.

Les Orectolobiformes, Carcharhiniformes et Myliobatiformes (Elasmobranchii, Neoselachii) des Bassins a phosphate du Maroc (Maastrichtien-Lutetien basal): Systematique, biostratigraphie, evolution et dynamique des faunes. Palaeo Ichthyologica 8.

[This one is harder to find. I asked for it and a couple of other Palaeo Ichthyologica issues for Christmas/birthdays over time but still don't have the most recent shark-related one.]

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His name is Bretton Kent and the book is Fossil Sharks of the Chesapeake Bay Region. It may sound kind of localized, but the descriptions tell where teeth have been found worldwide and it does feature great illustrations of all species mentioned, with multiple pictures showing different tooth positions. There are several diagrams of complete dentitions. It really is a great reference book. The bible is probably Cappetta's Handbook of Paleoicthyology, but that is a pricey one if you can find it.

Yes, this was a great book when it came out. It fleshed out more about sharks especially in combination with the Welton and Farish book on Cretaceous sharks and rays of Texas that was published the year before. One weakness with the Kent book was the use of drawings instead of photos especially with the dentitions. It's better to deal with something concrete rather than idealized but I don't want to be too critical on that point because it's better to have good drawings than blurry photos.

Like the Texas book, the Kent book covered many species that are found in other parts of the world. It provided another perspective for collectors before the Internet and its mix of the informative (elasmo.com) and the ridiculous (some dealer sites).

Cappetta's book isn't really an ID guide in that it doesn't show many tooth positions for each genus. It is a nice review of the known genera as of 1987 but it also has drawings as its primary form of illustration. His new edition is supposed to be published this summer and is said to have numerous photos.

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I don't think anyone would fault you for saying they are S. aschersoni. The Brachycarcharias is another fairly new species for me as well. Until this thread started, I hadn't given them much thought, and as I said earlier, S. gafsana is a totally new species to me. I think I would like to see more examples of each before I could differentiate between them with reasonable confidence. This has been a great learning experience for me though and for that I thank you Harry.

ps Cris: I agree with Harry-great teeth

S. aschersoni and S. gafsani look a little alike but aschersoni upper crowns are generally narrower and proportionally higher relative to the width of the root. The crown is also less convex across the labial face. The well-developed lateral cusplets, however, provide the most apparent distinguishing feature. They are longer, narrower, sharper, and strongly compressed labiolingually (these comments are based on Arambourg, 1952).

If you have access to Arambourg (1952), Plate XIX shows teeth of both species and differences are clear. C. gafsana does show more widely-extended root lobes relative to the crown height with a broader crown base with shorter and less-pointed lateral cusplets.

S. gafsana is best known from the Early Eocene of Tunisia and has not been officially recorded from Morocco as far as I know, while aschersoni is found in Morocco but not Tunisia. This seems weird since the environment was much the same across North Africa at the time.

As an additional note, I have an email from David Ward dated 13 July 1999 regarding aschersoni. He stated that aschersoni had not been seen from the London Clay most likely because it was cooler, deeper water there and aschersoni was a shallow water, subtropical animal. He added that Case (1994) mistakenly ID'ed a tooth as gafsana but it was aschersoni ("shallow root and bizarre lateral cusps"). He also said that gafsana had been found in the Late Paleocene Upnor Formation, UK and the Nanjemoy Formation of the USA, disagreeing with elasmo.com's ID of aschersoni at the time.

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S. aschersoni and S. gafsani look a little alike but aschersoni upper crowns are generally narrower and proportionally higher relative to the width of the root. The crown is also less convex across the labial face. The well-developed lateral cusplets, however, provide the most apparent distinguishing feature. They are longer, narrower, sharper, and strongly compressed labiolingually (these comments are based on Arambourg, 1952).

If you have access to Arambourg (1952), Plate XIX shows teeth of both species and differences are clear. C. gafsana does show more widely-extended root lobes relative to the crown height with a broader crown base with shorter and less-pointed lateral cusplets.

S. gafsana is best known from the Early Eocene of Tunisia and has not been officially recorded from Morocco as far as I know, while aschersoni is found in Morocco but not Tunisia. This seems weird since the environment was much the same across North Africa at the time.

As an additional note, I have an email from David Ward dated 13 July 1999 regarding aschersoni. He stated that aschersoni had not been seen from the London Clay most likely because it was cooler, deeper water there and aschersoni was a shallow water, subtropical animal. He added that Case (1994) mistakenly ID'ed a tooth as gafsana but it was aschersoni ("shallow root and bizarre lateral cusps"). He also said that gafsana had been found in the Late Paleocene Upnor Formation, UK and the Nanjemoy Formation of the USA, disagreeing with elasmo.com's ID of aschersoni at the time.

If you have access to Arambourg, how about scanning and posting the plates you reference.

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This old thread is getting interesting again. Please Jess, post some pics or as Harry mentioned, scans of articles. This is what I love about this hobby

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Jess, or anyone else for that matter, would you know where the miocene site is in the Western Sahara? The Eocene teeth are coming from Ad-Dakhla as far as I know, but I can't find the source for the Miocene megs and makos

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Here's a link to a PDF of a bivalve study of the Upper Miocene of the Sais Basin; maybe something to start a Google search with?

My link

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I won't argue with you about whether your Moroccan teeth are dyed or not. But I know I have never seen preservation like that from Morocco and they sure look a lot like the dyed teeth that I ended up with. And your pictures are always VERY GOOD so I doubt the blackness of the roots is an "artifact". You can see how the dye has seaped into the growth cracks, no??? The species you have are common and available for sale all over the internet. Maybe you could point me to a website that has some with similar preservation to yours????

Maybe someone else has seen Moroccan teeth with preservation like this??? I admit I could be wrong, but I just have not seen it before. And we all know how common Moroccan teeth are.... someone should have seen it if they are out there.

.steve

Steve,

I have also seen black in a black matrix. One dealer called the site "Gigou near Seffrou" and I've heard of another site. I started seeing these teeth several years ago.

In Noubhani and Cappetta (1997) they note that the Moroccan sediments (and therefore the fossils) can range from black (because of their richness in organic material, particularly the Maastrichtian, and in the Danian of one site, Yousouffia, in the Ganntour Basin) to white, the color of several beds of different ages. The article noted yellow, brown, gray, and gray mottled with red.

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If you have access to Arambourg, how about scanning and posting the plates you reference.

Harry,

I will try to do that tomorrow. I don't have a scanner or a good camera but my brother does. I would've tried today but am recovering from food poisoning (second worst case I've dealt with ever).

Jess

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This old thread is getting interesting again. Please Jess, post some pics or as Harry mentioned, scans of articles. This is what I love about this hobby

Northern,

I will get some teeth together too and try to get them photographed as well.

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Jess, or anyone else for that matter, would you know where the miocene site is in the Western Sahara? The Eocene teeth are coming from Ad-Dakhla as far as I know, but I can't find the source for the Miocene megs and makos

Northern,

I saw a photo of cliff face where the teeth were said to have been collected and it was near the coast but the site did not have a name. I can ask around.

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If you have access to Arambourg, how about scanning and posting the plates you reference.

Here's a scan of the Arambourg (1952) showing teeth of "Lamna" gafsana and aschersoni.post-1482-084943000 1275875716_thumb.jpg

It didn't come out as clear as I hoped but it comes out okay when you click on it.

Edited by siteseer

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