Extreme posterior shark teeth!

[Wolf89]

[ynot]

1 hour ago, Wolf89 said:

What are y'alls opinion on this tooth

Do not know the species, but it looks like a symphyseal tooth to Me.

Neat tooth regardless.

[digit]

C. taurus is the Sand Tiger Shark, a species that is reasonably common over here on the east coast fossil deposits. Can't remember if this species is found in the Shark Tooth Hill material that you are likely more familiar with. My first thought would be a symphyseal for any tooth that looks small and unlike others in the set. The figure on page 25 of this paper (an illustration modified from Compagno) makes me wonder if this might be a lateral (posterior) tooth from a species that looks to have a lot of tiny teeth in the back of its jaw. It's a pretty impressive shrinkage of tooth size compared to the size of the anterior teeth.

 

 

https://www.researchgate.net/publication/256841137_Analysis_of_dental_insertion_angles_in_the_sand_tiger_shark_Carcharias_taurus_Chondrichthyes_Lamniformes

 

Would love to hear what others think of this tiny tooth with the side cusps. @Al Dente?

 

 

Cheers.

 

-Ken

[Al Dente]

17 minutes ago, ynot said:

Do not know the species, but it looks like a symphyseal tooth to Me.

Neat tooth regardless.

I agree.

[MarcoSr]

17 hours ago, ynot said:

Well here is a different one.

I think it is a hexanchus.

 

Tony

 

It is very possible that this is a Hexanchus commissural tooth.  They can be much smaller than this specimen (down to 1mm in the extant jaws that I have).  I have only seen a few pictures of fossil Hexanchus commissural teeth because they are not found very often due to their small size and rarity.  If not a commissural tooth, it is possible that the tooth is a Heterodontus tooth but usually they are higher domed with a more prominent central ridge and side ridges.

 

Looking at my extant Hexanchus jaws due to the shape and size of your specimen, it does look like a commissural tooth after the regular teeth.  Unfortunately I don't have any pictures of my extant Hexanchus jaws.  However I do have pictures of one of my Heptranchias jaws which have very similar commissural teeth.  See below.

 

Upper Heptranchias jaw commissural teeth:

 

 

Lower Heptranchias jaw commissural teeth:

 

 

Great find!

 

Marco Sr.

[ynot]

Thanks @MarcoSr

[siteseer]

On 9/11/2018 at 8:13 AM, Al Dente said:

I agree.

 

I agree and think it's a Carcharhinus symphyseal.

[siteseer]

On 9/11/2018 at 8:45 AM, ynot said:

Thanks @MarcoSr

 

Tony and Marco Sr.,

 

I think it's a Hexanchus commissural tooth too.  It's a good match to a specimen in Herman, Hovestadt, and Hovestadt-Euler (1994: 161).

 

Jess

 

 

HERMAN, J., M. HOVESTADT-EULER, and D.C. HOVESTADT.  1994.
Contributions to the study of the comparative morphology of teeth and other relevant ichthyodorulites in living superaspecific taxa of Chondrichthyan fishes.  Addendum to Part A, No. 1: Hexanchiformes - Family: Hexanchidae. Odontological results supporting the validity of Hexanchus vitulus Springer & Waller. 1969 as the third species of the genus Hexanchus Rafinesque, 1810, and suggesting intrafamilial reordering of the Hexanchidae. Bulletin de l'Institut Royal des Sciences Naturelles de Belgique, Biologie, 64: 147–163.

 

 

[ynot]

1 hour ago, siteseer said:

I think it's a Hexanchus commissural tooth too. 

Thanks Jess.

[siteseer]

On 9/11/2018 at 8:13 AM, digit said:

C. taurus is the Sand Tiger Shark, a species that is reasonably common over here on the east coast fossil deposits. Can't remember if this species is found in the Shark Tooth Hill material that you are likely more familiar with. My first thought would be a symphyseal for any tooth that looks small and unlike others in the set. The figure on page 25 of this paper (an illustration modified from Compagno) makes me wonder if this might be a lateral (posterior) tooth from a species that looks to have a lot of tiny teeth in the back of its jaw. It's a pretty impressive shrinkage of tooth size compared to the size of the anterior teeth.

 

 

https://www.researchgate.net/publication/256841137_Analysis_of_dental_insertion_angles_in_the_sand_tiger_shark_Carcharias_taurus_Chondrichthyes_Lamniformes

 

Would love to hear what others think of this tiny tooth with the side cusps. @Al Dente?

 

 

Cheers.

 

-Ken

 

Hi Ken,

 

No, C. taurus isn't known from STH.  I don't think I've ever seen any sand tiger from there.  You can find sand tigers in the Olcese Sand, an older formation in the Bakersfield area.  It's just a couple of million years older than STH.  You get some of the same sharks but a different mix (Isurus is more common; C. hastalis and C. planus are absent; Echinorhinus more common, etc.).  Teeth are harder to find so most collectors in the area don't look for Olcese sites.  In four hours you might find over 80 teeth in the STH Bonebed, but in the Olcese (the shelly layer), you might find just 15-20 on a good day.  

 

Jess

 

 

Jess

[Rowboater]

@ynot Hi Tony, hope this is an appropriate place to ask about some teeth. You seem pretty expert on teeth! Most common here are sand tiger sharks so I should have some of the posterior ones (unless so small I miss them?)  Most commonly I think smaller teeth I find are just young teeth.  Have a lot to go through.

Before I go through those I picked through some lemon shark teeth (mostly beach teeth).  Most have the big cleft root (not the photo'ed side) and sides of blade which are visible only on the non-cleft side of the root.  Not sure all of these are lemon shark (particularly the top ones; the smaller ones at the bottom may be some posterior?

 

[ynot]

1 hour ago, Rowboater said:

, hope this is an appropriate place to ask about some teeth.

If You are looking for an ID it would be better to take individual pictures of the teeth and post a new thread in the fossil ID section.

 

All I know about shark teeth has been learned from others here on TFF, and I am still a novice with IDing them.

 

The top left tooth in Your picture could be a posterior sand tiger.

The center tooth of the bottom row could be a posterior but not sure of species.

The rest look like anterior or lateral teeth of 3 or 4 different species. It is hard to be sure with teeth that are so worn from beach tumbling.

 

Most of the posterior teeth I have came from searching micro matrix ( less than 1/4 inch).

[Rowboater]

Thanks Tony, I'll move to ID section.  I hurt my hip (hopefully temporarily) so will take scans and learn.

[ynot]

Thought I would bump this in hopes of getting some more postings of posterior shark teeth.

[Macrophyseter]

Here's my recently acquired megalodon posterior from the former Spanish Sahara, the length from root lobe to root lobe approaches around 1.5 inches or so.

 

[ynot]

8 hours ago, Macrophyseter said:

Here's my recently acquired megalodon posterior

Nice acquisition!

Thanks for adding it to this thread.

[ThePhysicist]

Love this thread! Here's my meager contribution: teeth from the Cretaceous of Texas. Biggest three are likely Scapanorhynchus, and anybody's guess on the smallest.

 

 

Edit: the smallest may actually be Cretodus sp. : http://www.thefossilforum.com/index.php?/gallery/image/51613-‘button-nose’-posterior-cretodus-crassidens-south-dakota/&browse=1

 

Edited January 15, 2021 by ThePhysicist

[ThePhysicist]

Found this yesterday:

 

Cretodus sp. (crassidens?)

Post Oak Creek, Sherman, TX

Eagle Ford Group, Late Cretaceous

4mm

 

[Untitled]

Scapanorhynchus texanus posterior 

Late Cretaceous 

Monmouth County, NJ personal find

[siteseer]

Here's a posterior Carcharocles megalodon from the early Pliocene of Sacaco, Peru.  It measures 3/4 inches (18mm) wide.  In the late 90's a couple of French importers brought a variety of fossils from Peru to Tucson but the Peruvian government outlawed export of them sometime in the early 2000's.  I was looking for the smaller stuff as well as the bigger teeth. 

[ynot]

Great teeth folks - Thanks to all who contributed to this thread.

 

I know there are some more nice posterior shark teeth to add- so let s see them.

[ynot]

Wanted to bump this thread and see if Y'all can post some more posteriors for Me?

 

[Thomas.Dodson]

I did find this posterior Cretolamna appendiculata at my last trip to W.M. Browning Fossil Park in north Mississippi. Demopolis Formation, late Campanian.

[Fin Lover]

Here's one I posted in April:

 

 

[Meganeura]

Gotta add in my 0.7” bone valley posterior Meg here!