Cetorhinus Sp.

[Gerard]

Hi all,

I found this Cetorhinus sp. from Bakersfield.

Does someone know the exact name? It looks like this tooth has a side spike or something.

Thanks!

Gerard

[siteseer]

Hi all,

I found this Cetorhinus sp. from Bakersfield.

Does someone know the exact name? It looks like this tooth has a side spike or something.

Thanks!

Gerard

Gerard,

Assuming it is from the Sharktooth Hill Bonebed (they are also found lower in the Round Mountain Silt and Olcese Sand), there have been a couple of species suggested over the years but it is best left in open nomenclature. Some of the teeth have a weak side cusplet like that along with other variations of the crown. Some have a globular root and some have a root with weakly branching lobes.

[Gerard]

Gerard,

Assuming it is from the Sharktooth Hill Bonebed (they are also found lower in the Round Mountain Silt and Olcese Sand), there have been a couple of species suggested over the years but it is best left in open nomenclature. Some of the teeth have a weak side cusplet like that along with other variations of the crown. Some have a globular root and some have a root with weakly branching lobes.

Can you tell me what species are suggested for that site (STH)?

Thanks!

Gerard

[siteseer]

Can you tell me what species are suggested for that site (STH)?

Thanks!

Gerard

I have seen the teeth named to three different species:

C. parvus: This name is incorrect because it was originally used to describe gill rakers with no associated teeth. Gill rakers are not diagnostic of a species so the name is invalid anyway. Moreover, the STH teeth are not a good match for any of the Cenozoic teeth I've seen from Europe (Oligocene of Germany; Miocene/Pliocene of Belgium).

C. maximus: This is the modern species. Its teeth do not show the same range of crown variation as the STH form so maximus is also incorrect.

C. occidentalis: I don't know where this name came from but it has not been officially proposed. Joe Cocke listed it as a junior synonym in his book, "Fossil Shark Teeth of the World." I asked him about that name in particular. He couldn't recall where he heard it first but a few collectors were using it. Perhaps it was a misunderstanding that spiraled into a life of its own.

I say that because in Jordan and Hannibal (1923), there is a suite of nine teeth identified as Gyrace occidentalis. Eight of the teeth are actually referrable to Galeocerdo and the other one is a Cetorhinus tooth (as pointed out in Bruce Welton's 1979 PhD dissertation during a discussion of another topic). Someone might have thought that occidentalis could then be a name for the Cetorhinus tooth, but without it being officially proposed in a peer-reviewed journal, it would not be available for formal usage and wouldn't make much sense for informal usage either.

[Gerard]

So the most safe ID will be Cetorhinus sp.?

Just as on elasmo.com :

Cetorhinus sp — Basking shark

Originally identified as C. cf maximus (GUNNER 1765) it now seems more appropriate to go with a more conservative identification. These teeth are deemed a common component of the fauna.

[siteseer]

So the most safe ID will be Cetorhinus sp.?

Just as on elasmo.com :

Cetorhinus sp — Basking shark

Originally identified as C. cf maximus (GUNNER 1765) it now seems more appropriate to go with a more conservative identification. These teeth are deemed a common component of the fauna.

Yes, until someone writes a formal description of the STH basking shark (probably a distinct species and one with a rather wide morphological range), it is best to call it Cetorhinus sp. It was identified on elasmo.com as C. maximus in the first version of its STH page (2002) and was reinterpreted after additional input for the 2008 revised page. You'd have to track back through various articles to see how the STH occurrence was first listed or mentioned. I don't have access to my articles at the moment.

[Gerard]

Thanks for your help!

Gerard

[siteseer]

Thanks for your help!

Gerard

Gerard,

I did find the first report of Cetorhinus in the STH Bonebed. It was by Bishop (1961), a brief, informal but informative review of the sharks and rays from the four shark tooth-bearing beds in the Bakersfield area. Richard Bishop (an expert on sharks) and his family did a lot of collecting during the 50's, 60's, and 70's and donated a lot of material (the extinct pinniped, Pinnarctidion bishopi, was named in his honor). I know one of his sons, Chuck, though I haven't seen him in a few years. He was still digging at a few of his secret spots then.

Anyway, Bishop (1961) listed the basking shark as "Cetorhinus sp." with "Cetorhinus maximus" in parentheses next to it.