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Searcher78

Shark Tooth

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Searcher78

Since I’m in lockdown, I’m going through old teeth. One small tooth in my Flag Pond, MD box had me stumped. I’m now leaning toward a small Galeocerno contortus. It is all black and hard to get a good picture.

FFBE60D7-C6FC-46E9-A0A0-6F1097AB7533.jpeg

7E45C4C1-33C2-49CF-BD83-D25A68F0F151.jpeg

D7F33972-BADB-4991-B2F0-B2FC9DDB92E9.jpeg

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hokietech96

It looks like it. There should be serrations on the distal shoulder I believe. Tooth so black I can’t tell

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Peto Lithos

A head-on photo would help, but from what I can see that looks correct as well.

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minnbuckeye
2 minutes ago, digit said:

 

By using a medium to darker gray background the camera can brighten the overall image resulting in better detail and less shadows.

Great tip! I always shoot teeth on a white background.

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digit

That's the natural inclination to provide a featureless background. Many scientific papers (digitally) cut out photographed specimens and place them on a white background in figures. Best to do that in post-editing and not actually while shooting dark subjects. Using a neutral (grayscale) background is important in that it helps the camera find a proper color balance. If the lighting imparts a cast (cooler blue or warmer red tones) photo editing software can restore a proper color balance using the gray of the background as a neutral color reference. I use gray card stock that has a lot of texture (fibers) in it as it helps in focusing. If I were shooting for a scientific paper where I wanted to digitally "subtract" the background leaving only the photographed item, I'd likely use a smoother gray background.

 

BTW: The tooth in the original posting does resemble a Galeocerdo contortus but at first the lack of detail made it look like a symphyseal Carcharius taurus which are very narrow teeth with the curve perpendicular to the tiger sharks. The lack of detail (shadowed) in the middle image of three above is what makes it resemble this symphyseal tooth. I think the detail of the root in the first image makes me lean toward the Galeocerdo.

 

 

Cheers.

 

-Ken

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Searcher78
8 hours ago, digit said:

That's the natural inclination to provide a featureless background. Many scientific papers (digitally) cut out photographed specimens and place them on a white background in figures. Best to do that in post-editing and not actually while shooting dark subjects. Using a neutral (grayscale) background is important in that it helps the camera find a proper color balance. If the lighting imparts a cast (cooler blue or warmer red tones) photo editing software can restore a proper color balance using the gray of the background as a neutral color reference. I use gray card stock that has a lot of texture (fibers) in it as it helps in focusing. If I were shooting for a scientific paper where I wanted to digitally "subtract" the background leaving only the photographed item, I'd likely use a smoother gray background.

 

BTW: The tooth in the original posting does resemble a Galeocerdo contortus but at first the lack of detail made it look like a symphyseal Carcharius taurus which are very narrow teeth with the curve perpendicular to the tiger sharks. The lack of detail (shadowed) in the middle image of three above is what makes it resemble this symphyseal tooth. I think the detail of the root in the first image makes me lean toward the Galeocerdo.

 

 

Cheers.

 

-Ken

Thanks for the tips. I will have to try it.

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Searcher78

Using a gray background. I also use a microscope which is not the easiest to get the best photos. Here are a few angles.

5D30482B-19E3-45A4-A763-74352BBD76EF.jpeg

A653A45E-E6A2-4042-A3B6-2FA70FCB1CD0.jpeg

659D9222-53BD-444E-8473-9A0CF7ECCCA7.jpeg

9FDC353A-AA90-425C-BA76-3E33C82D2EF5.jpeg

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digit

Disregard what I was saying before about Carcharias taurus (Sand Tiger) symphyseals--I was thinking about Hemipristis serra symphyseals which are very narrow and resemble the first of four images above when viewed from the side. Your tooth does indeed seem to be Physogaleus contortus. How big is it that you have to photograph it with a scope?

 

Here's an interesting reference showing both Physogaleus teeth and the Hemipristis of which I speak. You'll see the upper and lower symphyseals for this species (11&12 and 15&16) in the figure do resemble your tooth (29&30) when viewed from the side.

 

https://www.researchgate.net/figure/Carcharhiniformes-I-Hemipristis-Galeocerdo-and-Physogaleus-from-the-Chucunaque_fig12_316052378

 

Carcharhiniformes-I-Hemipristis-Galeocerdo-and-Physogaleus-from-the-Chucunaque.png

 

Cheers.

 

-Ken

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Searcher78
40 minutes ago, digit said:

Disregard what I was saying before about Carcharias taurus (Sand Tiger) symphyseals--I was thinking about Hemipristis serra symphyseals which are very narrow and resemble the first of four images above when viewed from the side. Your tooth does indeed seem to be Physogaleus contortus. How big is it that you have to photograph it with a scope?

 

Here's an interesting reference showing both Physogaleus teeth and the Hemipristis of which I speak. You'll see the upper and lower symphyseals for this species (11&12 and 15&16) in the figure do resemble your tooth (29&30) when viewed from the side.

 

https://www.researchgate.net/figure/Carcharhiniformes-I-Hemipristis-Galeocerdo-and-Physogaleus-from-the-Chucunaque_fig12_316052378

 

Carcharhiniformes-I-Hemipristis-Galeocerdo-and-Physogaleus-from-the-Chucunaque.png

 

Cheers.

 

-Ken

It was small (5 mm) like the sharp nose shark teeth I found.

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digit

If it's the size of the Rhizoprionodon teeth then it is from a really small Physogaleus. Nice find. That's the size of my largest Cookiecutter Shark (Isistius triangulus) teeth. :)

 

 

Cheers.

 

-Ken

 

 

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