serrated mako?

[Rowboater]

While collecting teeth I was surprised when what I thought was a ventral mako/ great white tooth had serrations (strong near the base, fine near the middle, nothing at the tip).  At first I thought this was a damaged hemipristis, but the shape of the tooth was different and serrations were smaller.  The tooth seems to be essentially the same as an unserrated mako/ great white, however the serrations are obvious.

 

Is this a transitional tooth between fossil mako and modern great white?  Or does this represent a totally different species?

[Fossildude19]

Maybe a Hemipristis serra? Lower? 

Not sure, but someone will weigh in shortly. 

Neat finds. 

[Darktooth]

I am pretty sure Tim's assessment is correct. But could you take a pic of the opposite side as well as side view? 

[digit]

Yup. Looks like a lower Hemipristis to me--they can have variable amounts of serrations from fully serrated to just a few serrations toward the base.

 

Some searches on this forum for "Hemipristis" should show a variety of specimens some possibly resembling your find. More information here as well:

 

https://www.fossilguy.com/gallery/vert/fish-shark/hemipristis/hemipristis.htm

 

EDIT: Looking closer at the photo on the left of the tooth in question, seems to show serrations on both sides up to near the tip. Lower Hemis tend to have a bit of a bulge at the middle of the root on the lingual side. A photo of the tooth in question from the other side would likely show this.

 

 

Cheers.

 

-Ken

[Rowboater]

Thanks Everyone!  I have limited experience (samples) of Hemipristis (the few I have came from a local beach, and are not ventral teeth), rarely see complete one's in my creek, and didn't realize they could have only minor serrations.  

[Rowboater]

On 9/19/2018 at 5:40 AM, sunbleached said:

You found some nice ones.  Is the river up with all the rain?  I was on the Chesapeake Sunday and the water was high.

 

11 hours ago, Fossildude19 said:

Maybe a Hemipristis serra? Lower? 

Not sure, but someone will weigh in shortly. 

Neat finds. 

 

11 hours ago, Darktooth said:

I am pretty sure Tim's assessment is correct. But could you take a pic of the opposite side as well as side view? 

 

11 hours ago, digit said:

Yup. Looks like a lower Hemipristis to me--they can have variable amounts of serrations from fully serrated to just a few serrations toward the base.

 

Some searches on this forum for "Hemipristis" should show a variety of specimens some possibly resembling your find. More information here as well:

 

https://www.fossilguy.com/gallery/vert/fish-shark/hemipristis/hemipristis.htm

 

EDIT: Looking closer at the photo on the left of the tooth in question, seems to show serrations on both sides up to near the tip. Lower Hemis tend to have a bit of a bulge at the middle of the root on the lingual side. A photo of the tooth in question from the other side would likely show this.

 

 

Cheers.

 

-Ken

from the side, the curvature of the blade is less than my two ventral mako teeth, and the root boss does seem more centralized than the mako teeth as Ken noted.  Thanks for the help!  New spot in the creek, hopefully more stuff to learn!

[digit]

56 minutes ago, Rowboater said:

New spot in the creek, hopefully more stuff to learn!

Isn't that the best.

 

 

Cheers.

 

-Ken