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What Is Your Take On This Cow Shark Tooth


Guest bmorefossil

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Upper lateral Notorhynchus primigenius

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I'm basing my opinion on species on 3 factors

1) The size. Of the 4 species of cow sharks in the area, I eliminated the ones that were significantly smaller

2) The fact that N. primigenius is the most common of the cow sharks in the area

3) Kent's book states something to the effect of Notorhynchus teeth having much more prominent mesial serrations than what is generally found on Hexanchus

The overall shape of the tooth is why I suggested upper lateral

I also was looking up this stuff at 5:30 am, so if my facts are wrong, blame a lack of coffee :blush:

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Guest bmorefossil
I'm basing my opinion on species on 3 factors

1) The size. Of the 4 species of cow sharks in the area, I eliminated the ones that were significantly smaller

2) The fact that N. primigenius is the most common of the cow sharks in the area

3) Kent's book states something to the effect of Notorhynchus teeth having much more prominent mesial serrations than what is generally found on Hexanchus

The overall shape of the tooth is why I suggested upper lateral

I also was looking up this stuff at 5:30 am, so if my facts are wrong, blame a lack of coffee :blush:

i have read up on it and have seen pictures from both species, as for the mesial serrations on my upper lateral teeth from n. primigenius the serrations are usually large and decrease in size as they reach the root, the serrations on this tooth start small become larger then become smaller again, this occurs on hex teeth.

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My first thought was Hexanchus gigas. They are rare along the cliffs but they do show up and they are the larger of the two species of cow sharks found in that area. It looks bigger than most of the Notorhynchus primigenius that are typically found there and most Notorhynchus that I have seen from that position exibit a small cusp-like serration on the anterior edge. The mesial serrations on your tooth are finer than most of the Notorhynchus I have seen but are a bit more coarse than those on the upper Hex teeth that I have. All of the upper Hex teeth I have are Pliocene and I only have about ten of them so there may be more variation that a larger sample than mine would show.

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Guest bmorefossil
My first thought was Hexanchus gigas. They are rare along the cliffs but they do show up and they are the larger of the two species of cow sharks found in that area. It looks bigger than most of the Notorhynchus primigenius that are typically found there and most Notorhynchus that I have seen from that position exibit a small cusp-like serration on the anterior edge. The mesial serrations on your tooth are finer than most of the Notorhynchus I have seen but are a bit more coarse than those on the upper Hex teeth that I have. All of the upper Hex teeth I have are Pliocene and I only have about ten of them so there may be more variation that a larger sample than mine would show.

so you dont think it is a hex?

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i have read up on it and have seen pictures from both species, as for the mesial serrations on my upper lateral teeth from n. primigenius the serrations are usually large and decrease in size as they reach the root, the serrations on this tooth start small become larger then become smaller again, this occurs on hex teeth.

I'm wondering if this could do with the sexual dimorphism these species display, or maybe a positional thing. I looked at the pics on Elasmo, and I can't see much in the way of mesial serrations on the upper Hexanchus teeth. The lowers vary between fairly consistant size and a bulge in the middle. The last photo they show of a N. cepedianus upper looks to me very similar to your specimen. Also, they say that N.primigenius may be a junior synonym of N. cepedianus, the extant taxon.

There's no limit to what you can accomplish when you're supposed to be doing something else

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so you dont think it is a hex?

It looks Hex-ish but it doesn't look like the Pliocene Hex teeth I have. My uppers have super fine mesial serrations and I have only seen lower Hex teeth from the Miocene, no uppers, so I don't know if their mesial serrations were more coarse than the Pliocene teeth. I think you would need to compare your tooth to a collection of Miocene Hex uppers.

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I'm wondering if this could do with the sexual dimorphism these species display, or maybe a positional thing. I looked at the pics on Elasmo, and I can't see much in the way of mesial serrations on the upper Hexanchus teeth. The lowers vary between fairly consistant size and a bulge in the middle. The last photo they show of a N. cepedianus upper looks to me very similar to your specimen. Also, they say that N.primigenius may be a junior synonym of N. cepedianus, the extant taxon.

Most of the literature I have read indicated that N. primigenius and N. cepedianus are considered to be the same species.

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Guest bmorefossil
It looks Hex-ish but it doesn't look like the Pliocene Hex teeth I have. My uppers have super fine mesial serrations and I have only seen lower Hex teeth from the Miocene, no uppers, so I don't know if their mesial serrations were more coarse than the Pliocene teeth. I think you would need to compare your tooth to a collection of Miocene Hex uppers.

yea i found one that someone found at lee creek and it looks so close to my tooth. other than that tooth i have only seen lowers

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Guest bmorefossil

well i dont know exactly what it is stil but Stephen Godfrey really liked my tooth alot and got really happy when he saw it, he said that he wants me to donate it to the museum, and that they are going to have it in the newsletter. So even if its not a hex its really cool

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yea the size throws me, but that 45 degree angle says no hex, but super cool. Iwonder if they are inbreed/

also i have gravel for sale check the trade room or my posts. god hunting.

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Cool find. For some reason I'm seeing and hearing that a lot more cow shark teeth are being found along the cliffs recently than earlier in the season.

Carpe Diem, Carpe Somnium

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Cool find. For some reason I'm seeing and hearing that a lot more cow shark teeth are being found along the cliffs recently than earlier in the season.

its a Hexanchus, the mesial teeth of a notorynchus on the front are bigger,

Greet Sean

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Guest bmorefossil
its a Hexanchus, the mesial teeth of a notorynchus on the front are bigger,

Greet Sean

and the size of it lol, being over 1" x 1"

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