Help needed in fossil sharks ID (Paleocene of Chile)

[terminatordiego]

Hello to all of you guys, I´m a newbie to the forum, so i would like to before anything, say hi to everyone here

And with that already said, i would need some help with the identification of some fossils of Elasmobranchii, that I have seen near the coast of south central Chile. The fossils are 2 teeth and something else that I´m unable to ID correctly (I think maybe a vertebra? or some weird gastropod). The age of the sandstone that contains these should be around the Upper Paleocene.

 

 

 

The fisrt tooth I think is from some (I think) sand tiger shark (something near Carcharias), and correspond to an upper lateral or near upper posterior position. My best shots right now around this are some sp. of Carcharias, Brachycarcharias, and even Striatolamia but for me it would not be weird if its something else. Here the photos (each segment of the scale is a milimeter):

 

 

 

 

And the second one is, for me, some lateral tooth of a Paraorthocodus, but not sure about the sp. of it. Should be somewhere near P. eocaenus or P. clarkii?. Here the images:

 

 

Finally, the misterious one. Here the photo:

 

thanks for reading, and help would be very nice (sorry if my english is not the best)

Edited August 31, 2021 by terminatordiego

[Mainefossils]

Very nice teeth! And, by the way, I think your English is excellent. We have some experts on shark teeth on this forum, I think that @Al Dente and @Praefectus should be able to point you in the right direction. 

 

Welcome to the Forum! 

[bthemoose]

Cool teeth! I agree on sand tiger for the first (though not sure which genus) and Paraorthacodus sp. for the second (if I found it here in Maryland, USA, I’d call it P. clarkii). Hopefully someone else will be able to narrow things down further.

[Praefectus]

Upper Paleocene of Chile? Wow, unique location. I am not 100% sure of the identification, but the tooth on the left kinda looks like Cretolamna.

[terminatordiego]

Thanks so much for replying!!!

And indeed, is quite an unique location, and not well known or studied yet the specific fauna in these upper paleocene strata.

[Tidgy's Dad]

Hello, Diego, and a very warm welcome to TFF from Morocco. 

Nice finds, you have a good eye. 

I think your mystery item is a shark vertebra. 

Or maybe another type of little fishy. 

[FossilDAWG]

@MarcoSr may be able to offer suggestions.  He is very familiar with the Paleocene fauna of the Chesapeake area.

 

Don

[Notidanodon]

Hi Diego very nice finds, the paraorthacodus is P.eocaenus, the striations are more pronounced than clarkii  

[MarcoSr]

On 8/31/2021 at 7:43 PM, FossilDAWG said:

@MarcoSr may be able to offer suggestions.  He is very familiar with the Paleocene fauna of the Chesapeake area.

 

Don

 

 

I'm not that familiar with the different faunas of Chile.  From what I know of the Paleocene of Chile, the shark teeth are scarce and mostly reworked.  These teeth definitely don't look like they are reworked.  So I'm questioning whether they are from the Paleocene or the Maastrichtian, Cretaceous of Chile.  The second tooth is Paraorthacodus sp.  Cappetta in his 2012 Handbook does not list Paraorthacodus from Chile or even from South America.  So with Cappetta not listing any species of Paraorthacodus from South America and not knowing the fauna, I can't say more.  The first tooth looks like it could be a Cretaceous tooth like Archaeolomna sp. or Cretalamna sp.  If the fauna is indeed Paleocene, I  would go with Cretalamna sp.  Note, I've never seen a scale like in the pictures before. Are the increments 2 mm?

 

Marco Sr.

[terminatordiego]

1 hour ago, MarcoSr said:

 

 

I'm not that familiar with the different faunas of Chile.  From what I know of the Paleocene of Chile, the shark teeth are scarce and mostly reworked.  These teeth definitely don't look like they are reworked.  So I'm questioning whether they are from the Paleocene or the Maastrichtian, Cretaceous of Chile.  The second tooth is Paraorthacodus sp.  Cappetta in his 2012 Handbook does not list Paraorthacodus from Chile or even from South America.  So with Cappetta not listing any species of Paraorthacodus from South America and not knowing the fauna, I can't say more.  The first tooth looks like it could be a Cretaceous tooth like Archaeolomna sp. or Cretalamna sp.  If the fauna is indeed Paleocene, I  would go with Cretalamna sp.  Note, I've never seen a scale like in the pictures before. Are the increments 2 mm?

 

Marco Sr.

Hello Mr. Marco, indeed you are absolutely correct about the increments of the scale (my bad ), gonna try to edit for correction right now.

About the geologic meaning of the fossils, certainly there are shark teeth in the Maastrichtian of central Chile (Quiriquina Formation), and also there are, but very less described, in the Lebu Group that is overlying Quiriquina Fm. The Lebu Group extends from Mid or Upper Paleocene to Upper Eocene, and outcrop in most places next  or near Quiriquina Fm. Besides that, I´m currently working on my graduate degree (Geologist) thesis on a certain place geology including not only Quiriquina Fm., but also the Lebu Group (from base to top, Pilpilco Fm, Curanilahue Fm, Boca-Lebu Fm, Trihueco Fm and Millongue Fm) and I´ve also visited alone and in field work with a local university the type localities of these formations. The level with the teeth that I posted is overlying Quiriquina Fm. in paraconformity (Hiatus + erosion), representing an outcrop of Pilpilco Fm. Also, I´m aware of Cappetta or any other relevant work not listing and not referencing these taxons in Chile, the papers about it are really very scarce due to lack of support for research (for several reasons).

I think the are a couple of less noticed papers (generally only describing down to genus level and validating a Paleocene age) about the teeth in the study area I´m currently working, if anyone is interested I´ll be happy of providing it, or more information about Chile´s particular geology/paleontology or by private messages with any questions, I´ll be also very glad to help in anything.

Thanks for replying!!!!!!!!!!!!!!!!!!

Edited September 2, 2021 by terminatordiego