Sharktooth Hill Finds Needing ID! Baby Meg?

[dinoshark]

hi guys! 

i was fortunate enough to get to visit the ernst quarries at bakersfield, california, near sharktooth hill for the first time this past weekend. was able to find a lot of teeth (76 total, 54 complete ones), but i need help identifying the species  especially when it comes to the makos, i have a really hard time telling apart the species with the lower jaw teeth. i also know there are tiger sharks galeocerdo and a physogaleus - how can i tell the difference between these two species?

 

can someone please help me identify the species i was able to find? thank you so much in advance!! 

 - the first one hemipristis serra was easy to identify, but the species for the others are tricky!

 

 

as for one particular tooth, i have no idea, but it really looks like a meg tooth especially with the bourlette and the general heart shape - perhaps a really small one?   i circled it in blue. can someone please confirm if this is a meg, or another species?

 

 

 

 

 

[Al Dente]

6 hours ago, dinoshark said:

as for one particular tooth, i have no idea, but it really looks like a meg tooth especially with the bourlette and the general heart shape - perhaps a really small one?   i circled it in blue. can someone please confirm if this is a meg, or another species?

It is Carcharhinus. I’m not sure which species.

[hemipristis]

8 hours ago, dinoshark said:

as for one particular tooth, i have no idea, but it really looks like a meg tooth especially with the bourlette and the general heart shape - perhaps a really small one?   i circled it in blue. can someone please confirm if this is a meg, or another species?

 

 

 

 

 

 

The Sharktooth Hill fauna predates the Carcharhinius radiation by a couple of million years.  Currently, three Carcharhinus  "species" (more like general morphologies) are recognized in the fauna, and there is wide morphological variation within each, suggesting that should some brave soul have a large enough sample size, good eyes, and a lot of time on their hands, several more species could likely shake out.

 

The 3 "species":

• Carcharhinus cf limbatus (blacktip)/ C. cf brachyurus (copper shark or bronze whaler):  small, <1cm, narrow blade

 

 

 

• Carcharhinus cf obscurus: general shape and size as the current C. obscurus (dusky shark)/C. leucas (bull shark)

 

 

 

• C. "ergotoni" aka C. "priscus" aka C. "gibbesi" group: general size and morphology of C. falciformis (silky or soupfin shark) with its distinct shoulder notches, tends to be larger than Carcharhinus cf limbatus (blacktip)/ C. cf brachyurus, and the crown is wider.

 

 

 

 

 

Some add a 4th species, the more archaic C. antiquus to the mix, but I have been unable to find any photo or graphic.

 

I believe your tooth falls into basket #3, C. "ergotoni", upper anterior position

 

 

 

 

 

Edited June 19 by hemipristis

[Coco]

I think I also see 2 Squatina, they are teeth that sit on their root, to the left of the 3rd line.

 

Coco

[dinoshark]

On 6/19/2024 at 1:30 AM, Al Dente said:

It is Carcharhinus. I’m not sure which species.

 

On 6/19/2024 at 3:10 AM, hemipristis said:

The Sharktooth Hill fauna predates the Carcharhinius radiation by a couple of million years.  Currently, three Carcharhinus  "species" (more like general morphologies) are recognized in the fauna, and there is wide morphological variation within each, suggesting that should some brave soul have a large enough sample size, good eyes, and a lot of time on their hands, several more species could likely shake out.

 

The 3 "species":

• Carcharhinus cf limbatus (blacktip)/ C. cf brachyurus (copper shark or bronze whaler):  small, <1cm, narrow blade

 

 

 

• Carcharhinus cf obscurus: general shape and size as the current C. obscurus (dusky shark)/C. leucas (bull shark)

 

 

 

• C. "ergotoni" aka C. "priscus" aka C. "gibbesi" group: general size and morphology of C. falciformis (silky or soupfin shark) with its distinct shoulder notches, tends to be larger than Carcharhinus cf limbatus (blacktip)/ C. cf brachyurus, and the crown is wider.

 

 

 

 

 

Some add a 4th species, the more archaic C. antiquus to the mix, but I have been unable to find any photo or graphic.

 

I believe your tooth falls into basket #3, C. "ergotoni", upper anterior position

 

 

 

 

 

 

thank you! carcharhinus does seem to be the likely name here - i looked it up and also saw a tooth on elasmo from carcharhinus limbatus that looked almost identical. i will label the mystery tooth as c. ergotoni! 

[dinoshark]

On 6/19/2024 at 3:26 PM, Coco said:

I think I also see 2 Squatina, they are teeth that sit on their root, to the left of the 3rd line.

 

Coco

thank you! do you think they could be s. lerichei?

[Coco]

I do not know, but in any case to have a certainty it would take close-up photos !

 

Coco