Guide for ID of Moroccan Sand Tigers (Odontaspidae)

[Doctor Mud]

Hi everyone,

 

I've put this post in the Fossil ID area as I think it is a suitable place for it. I'm in the process of identifying 1000s of Moroccan sand tiger teeth and I've been accumulating all the information I could find.

There is no one piece of literature that does it all. I hope to update this through time and get feedback from those more knowledgeable than myself that all the information is correct. Let me know if I have made a mistake and I will correct it. I hope this will be a useful resource for everyone.

 

First, here is Arambourg 1952: http://hybodus.free.fr/maroc/Arambourg%20%20&%20alii%20Vert%E9br%E9s%20fossiles%20des%20gisements%20de%20

(Copy and paste into your browser)

 

Now, there have been a few revisions since 1952. Here is what I could find:

 

        Name in Arambourg 1952                                             New valid name (if applicable)

O. whitei Arambourg, 1952                                               Striatolamia whitei (Arambourg, 1952)

O. macrota premut. striata (Winkler) 1874                        Striatolamia macrota (Agassiz, 1843)

O. robusta var. africana Arambourg, 1952                        Carcharias robustus africanus (Arambourg, 1952)

O. hopei s./sp. atlantica Arambourg, 1952             

O. koerti (Stromer) 1910                                                   Brachycarcharias koerti (Stromer, 1910)

O. tingitana Arambourg, 1952                                          Carcharias tingitana (Arambourg, 1952)

O. speyeri Dart. et Casier, 1943                                  

O. substriata Stromer, 1910                                             Carcharias substriatus (Stromer, 1910)

O. substriata mut. atlasi Arambourg, 1952                       Brachycarcharias atlasi (Arambourg, 1952)

O. vincenti (Woodward) 1899                                           Brachycarcharias  lerichei (Casier, 1946)

O. winkleri Lerice 1905

 

Note that O. stands for Odontaspis. If the space in the "new valid name" column is blank, then the name in Arambourg 1952 is still valid.

[Doctor Mud]

Now here is a summary taken from all the figures in Arambourg 1952 that should be a helpful starting place for ID. What I would like for this thread is to eventually have nice photographs to replace all of the originals from Arambourg. In this image, all teeth are to scale and have their current valid names. There is a scale bar that is 20 mm high. I have sampled examples of important tooth positions to give an idea of tooth variation. Cusps are enlarged. Note that Striatolamia and sometimes Brachycarcharias atlasi have striations (grooves) on the lingual (sometimes called display side) and this can be a helpful feature for ID.

 

 

[siteseer]

On August 20, 2017 at 5:16 AM, Doctor Mud said:

Hi everyone,

 

I've put this post in the Fossil ID area as I think it is a suitable place for it. I'm in the process of identifying 1000s of Moroccan sand tiger teeth and I've been accumulating all the information I could find.

There is no one piece of literature that does it all. I hope to update this through time and get feedback from those more knowledgeable than myself that all the information is correct. Let me know if I have made a mistake and I will correct it. I hope this will be a useful resource for everyone.

 

First, here is Arambourg 1952: http://hybodus.free.fr/maroc/Arambourg%20%20&%20alii%20Vert%E9br%E9s%20fossiles%20des%20gisements%20de%20

(Copy and paste into your browser)

 

Now, there have been a few revisions since 1952. Here is what I could find:

 

        Name in Arambourg 1952                                             New valid name (if applicable)

O. whitei Arambourg, 1952                                               Striatolamia whitei (Arambourg, 1952)

O. macrota premut. striata (Winkler) 1874                        Striatolamia macrota (Agassiz, 1843)

O. robusta var. africana Arambourg, 1952                        Carcharias robustus africanus (Arambourg, 1952)

O. hopei s./sp. atlantica Arambourg, 1952             

O. koerti (Stromer) 1910                                                   Brachycarcharias koerti (Stromer, 1910)

O. tingitana Arambourg, 1952                                          Carcharias tingitana (Arambourg, 1952)

O. speyeri Dart. et Casier, 1943                                  

O. substriata Stromer, 1910                                             Carcharias substriatus (Stromer, 1910)

O. substriata mut. atlasi Arambourg, 1952                       Brachycarcharias atlasi (Arambourg, 1952)

O. vincenti (Woodward) 1899                                           Brachycarcharias  lerichei (Casier, 1946)

O. winkleri Lerice 1905

 

Note that O. stands for Odontaspis. If the space in the "new valid name" column is blank, then the name in Arambourg 1952 is still valid.

 

Doctor Mud,

 

As you know with shark teeth, it isn't always a matter of correct or incorrect, but whose interpretation you are following.  Besides Arambourg (1952) what other publications are you referencing.  Of the top of my head you should read Cunningham (2000) for a brilliant review of Striatolamia and odontaspidids in general as well as an alternate way of displaying a dentition.  A couple of other references listed below.

 

Jess

 

Cunningham, S.B. (2000)
A comparison of isolated teeth of early Eocene Striatolamia macrota (Chondrichthyes, Lamniformes), with those of a Recent sand shark, Carcharias taurus. Tertiary Research, 20 (1–4): 17–31, 17 pl., 1 tbl.

 

Long, D.J. 1992.

Sharks of the La Meseta Formation (Eocene), Seymour Island, Antarctic Peninsula. Journal of Vertebrate Paleontology 12(1): 11-32.

 

Purdy, R.W. 1998.

Chondrichthyan Fishes from the Paleocene of South Carolina. In A.E. Sanders (ed.). Paleobiology of the Williamsburg Formation (Black Mingo Group; Paleocene) of South Carolina, U.S.A. Transactions of the American Philosophical Society. Vol. 88, Pt. 4.

 

[Doctor Mud]

Thanks Jess @siteseer

 

Thanks for the papers. I'll have to check my library and see if I have those yet. I appreciate your input as I can tell you know more than I do from your posts through the years.

 

Excellent point regarding taxonomy and I'm sure the sand tigers is a group that could be the subject of debate. 

in terms of being "correct" I mean - do I have the latest valid genus and species names. Am I so far off with my IDs that my interpretation isn't logically sound and wouldn't fit with any possible taxonomy.

 

I found it a bit daunting entering the world of sand tiger taxonomy and Arambourg has been the starting point.

My approach has been to start of assuming Arambourg correctly assembled artificial tooth sets for various taxa, but that the taxonomy is probably no longer correct. I have then looked at the taxonomic database to look for the history of name changes and the currently valid taxonomy.

 

I guess for me a major goal is to develop artificial tooth sets for sand tiger taxa.

 

Do you think Arambourg's tooth sets are still valid and that the taxonomy has just changed? 

 

 

 

 

 

 

[siteseer]

On 9/14/2017 at 4:15 AM, Doctor Mud said:

Thanks Jess @siteseer

 

Thanks for the papers. I'll have to check my library and see if I have those yet. I appreciate your input as I can tell you know more than I do from your posts through the years.

 

Excellent point regarding taxonomy and I'm sure the sand tigers is a group that could be the subject of debate. 

in terms of being "correct" I mean - do I have the latest valid genus and species names. Am I so far off with my IDs that my interpretation isn't logically sound and wouldn't fit with any possible taxonomy.

 

I found it a bit daunting entering the world of sand tiger taxonomy and Arambourg has been the starting point.

My approach has been to start of assuming Arambourg correctly assembled artificial tooth sets for various taxa, but that the taxonomy is probably no longer correct. I have then looked at the taxonomic database to look for the history of name changes and the currently valid taxonomy.

 

I guess for me a major goal is to develop artificial tooth sets for sand tiger taxa.

 

Do you think Arambourg's tooth sets are still valid and that the taxonomy has just changed? 

 

 

 

 

 

 

 

 

You should read other pubs like the two guides on London Clay fossils by Clouter, Rayner, Rayner, and Mitchell, Kent's 1994 book on sharks of the Chesapeake Bay Region, as well as Cappetta & Nolf's review of sand tigers, where some of the newer names were proposed (and elasmo.com's comments on that article).  Really, you should hunt down anything that reviews Paleocene and Eocene sharks to get a handle on various researcher's comments.  

 

There was a radiation of sand tigers in the Paleocene to Early Eocene coinciding with warming oceans flooding lowlands worldwide and radiating bony fish groups as well.  As a worldwide cooling trend started in the mid-late Eocene, sand tiger diversity decreased.  It is a challenge to sort out isolated sand tiger teeth from the Paleocene and Early Eocene and I haven't looked at that situation in detail in years.  However, I am skeptical of so many genera being proposed.  Even going back just to Striatolamia, I think macrota should be assigned to Carcharias as I don't see a character that separates them (Carcharias has variable striations).  This isn't my idea.  I read Purdy's and Long's comments and they said it straight out.  Cunningham says it without stating it directly.  Siverson's opinion, stated on elasmo.com, doubted that Striatolamia is a sand tiger and may even be a descendant of Cretaceous Anomotodon!  He stressed studying Early Paleocene sand tiger/sand tiger-like teeth to see the basal groups from which all the diversity sprang.

 

Yes, when looking at Moroccan sharks from the phosphates, it all starts with Arambourg (1952).  Go ahead and get comfortable with those names and then see how the tooth forms have been reinterpreted.   Everything was Lamna before I started collecting fossils in the late 80's and then a lot of teeth started to be called Cretolamna with a few becoming Serratolamna by that time.  When teeth started coming out of Kazakhstan by the late 90's, you saw some unusually large specimens of some forms (Jaekelotodus, Striatolamia) and you got the idea that some oddball teeth might still belong to established taxa.

 

I saw that there's a review of the Middle Eocene teeth from Point-A-Dam area.  I don't have that.  You should look for that too.  I would also write to some of those researchers.  See if you can get some extra info or a PDF out of any of them.  Most think it's great that people out there are interested.

 

I'd really have to take some time to put together better-presented comments and a list of publications but I didn't want to leave you hanging for weeks-months.

 

Jess

 

[siteseer]

Here's a site to check out:

 

http://users.telenet.be/sharkteethcollection/sharkteeth list totaal/totaal sharteeth list.htm

 

Jess