California Tooth ID

[sharko69]

Any ideas on this little tooth? C. hastilis or something else. Found in California, Monterey Formation.

[sagacious]

It does look somewhat like C hastalis,  but based on your photos above, I think it's more likely I oxyrinchus.  

 

You have a very nice collection there. Can we see some more of it?

 

 

[Macrophyseter]

I also think it could more likely to be Isurus oxyrhinchus. If it were to be Cosmopolitodus hastalis, then I'd imagine the crown base to be a bit broader rather then curve inwards that much.

[sharko69]

6 hours ago, sagacious said:

It does look somewhat like C hastalis,  but based on your photos above, I think it's more likely I oxyrinchus.  

 

You have a very nice collection there. Can we see some more of it?

 

 

The box in the background are all of my Cali broken teeth. I have hunted in California only a few times. There are much better collections but I love every tooth I find wherever I find them. Here is the collection from Cali. My favorite are my two GW, one big and one small.

 

[sharko69]

A few more from the Cali collection.

[sharko69]

[sharko69]

And my favorites, the micro stuff.

[Scylla]

I wish I could get as organised as you with the display boxes and labels. Beautiful 

[FossilsAnonymous]

@sharko69 I agree with the others for I oxyrinchus. You have a beautifully organized collection.

[sixgill pete]

@sharko69 I am not convinced this tooth is I. oxyrinchus, though I have no other alternative at this time. Could you post some more pics of this tooth laying flat, not in your hand. Good, in focus close ups of labial and lingual sides. Also side views distally and mesially. Could you give us good measurements on the length and width along with thickness, preferably in millimeters. Showing it in your hand does not tell us the size, we have no idea how big or small your hands are. Also please give us some good photos of the cusp like projections on each shoulder of the tooth.

The Monterey Formation from what I can find is well know for crabs and fossil fish, but not so much teeth, It also seems to be spread over much of coastal southern and central California. I am trying to find a list list of known shark species from this formation, as it may help in identification. It may be I. oxyrinchus, but at this time I am not convinced.

 

@Boesse

[Macrophyseter]

3 hours ago, sixgill pete said:

The Monterey Formation from what I can find is well know for crabs and fossil fish, but not so much teeth, It also seems to be spread over much of coastal southern and central California. I am trying to find a list list of known shark species from this formation, as it may help in identification. It may be I. oxyrinchus, but at this time I am not convinced.

I am not sure how much different each location in the Monterey formation is. The outcrop that my city is located in doesn't really see many crabs like San Luis, but has some shark teeth, including species like Cosmopolitodus hastalis, Carcharodon plicatilis, Carcharodon carcharias, Isurus oxyrinchus, Isurus planus, Hemipristis serra, Carcharias spp., Galeocedro spp., Carcharhinus spp, Carcharocles megalodon just to name a few. Still, they are pretty rare here and I've only found one shark tooth locally so far.

[sharko69]

5 hours ago, sixgill pete said:

@sharko69 I am not convinced this tooth is I. oxyrinchus, though I have no other alternative at this time. Could you post some more pics of this tooth laying flat, not in your hand. Good, in focus close ups of labial and lingual sides. Also side views distally and mesially. Could you give us good measurements on the length and width along with thickness, preferably in millimeters. Showing it in your hand does not tell us the size, we have no idea how big or small your hands are. Also please give us some good photos of the cusp like projections on each shoulder of the tooth.

The Monterey Formation from what I can find is well know for crabs and fossil fish, but not so much teeth, It also seems to be spread over much of coastal southern and central California. I am trying to find a list list of known shark species from this formation, as it may help in identification. It may be I. oxyrinchus, but at this time I am not convinced.

 

@Boesse

Thanks. I am out of town until the weekend but will be sure to take better pictures from the angles you requested.

[sharko69]

3 hours ago, Macrophyseter said:

I am not sure how much different each location in the Monterey formation is. The outcrop that my city is located in doesn't really see many crabs like San Luis, but has some shark teeth, including species like Cosmopolitodus hastalis, Carcharodon plicatilis, Carcharodon carcharias, Isurus oxyrinchus, Isurus planus, Hemipristis serra, Carcharias spp., Galeocedro spp., Carcharhinus spp, Carcharocles megalodon just to name a few. Still, they are pretty rare here and I've only found one shark tooth locally so far.

Thank you. The two GWs in the pictures are also from the same formation.

[siteseer]

4 hours ago, Macrophyseter said:

I am not sure how much different each location in the Monterey formation is. The outcrop that my city is located in doesn't really see many crabs like San Luis, but has some shark teeth, including species like Cosmopolitodus hastalis, Carcharodon plicatilis, Carcharodon carcharias, Isurus oxyrinchus, Isurus planus, Hemipristis serra, Carcharias spp., Galeocedro spp., Carcharhinus spp, Carcharocles megalodon just to name a few. Still, they are pretty rare here and I've only found one shark tooth locally so far.

 

 

It does vary from location to location and even at the same site.  At Monterey Formation sites in my area you find the pea crabs (Pinnixa galliheri) but mostly in a couple of layers.  I saw a Hexanchus from the Carmel area and heard about a "tiger shark" that was found years before.  In other layers you get mollusk imprints. 

 

Down in Orange County, there were rich sites found during construction in the 60's-70's particularly at Leisure World.  These teeth came out of the basal part of the formation which is slightly younger than Sharktooth Hill age (I think).  The crabs are younger from higher up in the formation - more like 9-12 million years old.

[Wolf89]

11 hours ago, sharko69 said:

The box in the background are all of my Cali broken teeth. I have hunted in California only a few times. There are much better collections but I love every tooth I find wherever I find them. Here is the collection from Cali. My favorite are my two GW, one big and one small.

 

You have a few really nice stuff in there including a cow shark and a dolphin tooth

[sharko69]

33 minutes ago, Wolf89 said:

You have a few really nice stuff in there including a cow shark and a dolphin tooth

One cow in there is from the same area as the GWs. Very fragile. Have yet to find a complete

one. There are a couple of broken pieces in there as well that are from STH.

[sixgill pete]

@siteseer Jess, what is you opinion on this tooth.

[sagacious]

I should have previously listed the reasons for my suggested identification.  If this tooth were potentially from C hastalis or C hubbelli or C carcharodon, it could only be a lower lateral, but it's far too thin labio-lingually to be a lower lateral tooth from those species. 

 

The list of possible suspects is fairly short. Lamna sp seems unlikely in this instance, as the crown might be expected to be thicker and more upright, and the side cusps should more erect and pointed.  To my mind, by far the most likely other option is Isurus oxyrinchus.  The crown cusp is fairly well-centered and slightly slanted, which matches well for a lower lateral I oxyrinchus.  On the question tooth above there appears to be a distinct nutrient groove in the location of the nutrient pores, and low side cusps.  I occasionally see I oxyrichus with low side cusps or 'shoulders', and a distinct groove in the area of the nutrient pores is also visible the one pictured below. 

 

Jess is spot-on about the exposures varying from site-to-site.  Very often the teeth from these exposures are broken or eroded significantly, or have extremely fragile roots, as sharko69 noted above.  Every once in a great while, a miracle happens and you find a really nice one, like the I oxyrinchus from Santa Cruz pictured below for comparison.  

 

 

[sagacious]

5 hours ago, sharko69 said:

Thank you. The two GWs in the pictures are also from the same formation.

Wow sharko69, that's certainly a very nice collection!  Thank you for the additional photos.  Really fantastic that you have them all set in cases and boxes so they can be easily seen, studied, and enjoyed.  Many very nice specimens in there, and I find a lot can be learned from even broken teeth.  The large great white is superb.  Definitely a collection to be proud of.

[sharko69]

On 11/15/2018 at 8:22 PM, sagacious said:

Wow sharko69, that's certainly a very nice collection!  Thank you for the additional photos.  Really fantastic that you have them all set in cases and boxes so they can be easily seen, studied, and enjoyed.  Many very nice specimens in there, and I find a lot can be learned from even broken teeth.  The large great white is superb.  Definitely a collection to be proud of.

Thank you. I am fortunate to travel for work and at times end up in areas where I can hunt and get lucky enough sometimes to find something. Thank you for the ID and clarification. I am adding the word shoulders to my shark tooth vocabulary. Describes the appearance of cusps perfectly.