Determine Real Fossil Shark Teeth including Megalodon using a dissecting microscope

[Biotalker]

I have been examining my megalodon teeth and even Ramanessin shark teeth and under the microscope I can usually see (presumably) enamel that had been laid down in thin lines that always turn and meet the tooth edges at a 90 degree angle. It is easiest to see in fossil teeth where the mineral coloring brings out these whitish lines. It is hard to see in extant white teeth. Here are 3 photos of what I mean. The horizontal lines are from the middle region of the meg tooth along the tooth axis. The picture with lines going both side-to-side and up-and-down is from the region near the edge. The picture of vertical lines and the edge of the tooth is where the enamel comes to a 90 degree angle with the edge of the tooth. Heck, even my dentist got animated when I explained what I was seeing in shark teeth.

 

Anyway, these white lines would be all but impossible to fake.

[Biotalker]

Magnification is about 90X.

[Gareth_]

Very interesting!

My question is why? Things like this (the evolutionary design of things) don't happen for no reason

A theory off the top of my head and I am absolutely no expert or scientist. 

Running the tooth axis - for outright bite force strength and allowing maybe a little flex. Bite force is perpendicular to the majority of the striations (much like trying to break wood against the grain)

Cross hatch pattern close to the edge - maximum breaking strength, stops any breakages entering or going past this region (like plywood - it's layered with opposing grain direction for strength)

Edge of tooth - running at 90 degrees to serrations, allowing for chips and breakage without sacrificing a larger piece of the tooth (thanks to cross hatch pattern just behind it). Facing this direction creates chips and not a lengthwise break (like breaking a sheet of wood with the grain)

 

Like I said, I'm no scientist but seeing your findings really got my attention and made me think "why"

 

 

 

Edited August 26, 2021 by Gareth_

[Gareth_]

On 9/6/2021 at 10:43 PM, eddie said:

 

 

 

[Gareth_]

@Biotalker I'd like to draw your attention to the pics above, they seem to highlight exactly what you were talking about - just without the microscope! Something in the fossilisation process highlighted the striations very vividly and I think it was worth posting here  

I still find it fascinating what you discovered under a microscope and without seeing what you showed I wouldn't have looked twice at the pattern on the pics above 
@eddie I hope you don't mind me posting your pics here, I can delete if you want but I find this topic very interesting and love to share knowledge

[Biotalker]

Wow! That is a magnificent tooth and does seem to highlight what I have observed (not discovered). Thanks for posting this Gareth, made my day.

 

[Biotalker]

I was inspired by @Gareth_'s post of @eddie pic of a multicolored meg tooth to acquire my own. I wanted to see if the lines of color deposition followed the direction of the enameloid fibers (also, of course, because I really wanted one super Meg tooth!). Here is the tooth, it a 5.2" from Indonesia.

[Biotalker]

So here are magnified views of the colored stripes of cream white, brown and black with visualization of the enameloid fibers. Colors and fibers do seem to correlate even though the color is deeper and the fibers more superficial. The color was presumably from mineralization that took place long after the enameloid deposition, so it unclear to me how the correlation happens. 

Here is a low mag view of a one region of the lingual edge.

[Biotalker]

With increasing magnification, one can see the fibers turning toward the direction of the edge......

[Biotalker]

and closer to the edge the colors have also turned and are going along with the fibers

[Biotalker]

Not a perfect correlation but interesting. 

 

Lastly, here is a pic of the fibers at the beginning of the crown.

[Josesaurus rex]

What magnifying glass or microscope have you used for those photos?  Can it be purchased in conventional stores or is it something more specialized?  Good images and good analysis of the teeth by the way.

[Biotalker]

On 10/31/2021 at 5:32 AM, Josesaurus rex said:

What magnifying glass or microscope have you used for those photos?  Can it be purchased in conventional stores or is it something more specialized?  Good images and good analysis of the teeth by the way.

It is a stereomicroscope- not a great one by any means- but fine. Its an Amscope stereoscope and you can see it  in my post below. You can get it with the boom so it will be steady above your fossil or with a regular stand. If you follow and wait, you might get it at 50% off sale.

 

[Gareth_]

On 10/31/2021 at 1:12 PM, Biotalker said:

Colors and fibers do seem to correlate even though the color is deeper and the fibers more superficial. The color was presumably from mineralization that took place long after the enameloid deposition, so it unclear to me how the correlation happens. 

 

Sorry about the delay in responding to your post. Totally nerding out on your latest pics, thank you for posting them.
Very nice excuse to add a 5"+ Meg tooth to your collection - you're buying it for science haha

....and a very nice specimen indeed! Overall, hard to fault it on anything

Is it possible the fibres are deeper than you suspect? Or the entire construction of the tooth follows the same general pattern you observed in enamel.... the enamel part of it is just easier to observe as it's slightly translucent. May explain why the mineralisation seems to correlate with the enamel. 

I feel like there is more to this story, it's definitely interesting! 

It's also a very, very useful piece of knowledge to have to help in spotting any restoration work before purchasing a Meg tooth if the sale is done in person. 

[Josesaurus rex]

On 11/1/2021 at 8:17 PM, Biotalker said:

It is a stereomicroscope- not a great one by any means- but fine. Its an Amscope stereoscope and you can see it  in my post below. You can get it with the boom so it will be steady above your fossil or with a regular stand. If you follow and wait, you might get it at 50% off sale.

 

Yes, I will do it.  I'll start looking for some.  It seems to me that it is a good tool to acquire.  I saw that there are various prices and increases.  I think I'll pick a more moderately priced one to start with and test how it works for me.

[Biotalker]

22 minutes ago, Josesaurus rex said:

Yes, I will do it.  I'll start looking for some.  It seems to me that it is a good tool to acquire.  I saw that there are various prices and increases.  I think I'll pick a more moderately priced one to start with and test how it works for me.

These Amscope microscopes are modular, meaning you can buy a stereomicroscope with the simple stand, and later just buy the boom and fit your scope into it. Also, you can increase or decrease magnification with lenses you can screw on underneath. It might also be a good idea to get the basic stereoscope unit with a 3rd port for a digital camera attachment.

[Josesaurus rex]

57 minutes ago, Biotalker said:

These Amscope microscopes are modular, meaning you can buy a stereomicroscope with the simple stand, and later just buy the boom and fit your scope into it. Also, you can increase or decrease magnification with lenses you can screw on underneath. It might also be a good idea to get the basic stereoscope unit with a 3rd port for a digital camera attachment.

Great!  Thank you very much, I will be reviewing what I find, I imagine that the brand is amscope, and that each accessory would be standard to be able to invite you, right?