What is this Odd Symmetrical Fossil? northern South Carolina Beach

[TheSuddenFox]

I found this odd and extremely symmetrical fossil washed up on the northern SC shore. I can best describe it as a rhombohedron (kite shaped, but extended out), about 1.5x1x1cm. It has a straight cut from the top to bottom face, as if it is a nasal structure, but I have no idea. Also the bottom side has 2 circular divots. Any ideas?

[PeaceRiverHistory]

Looks like a fish bone, most likely a skull piece but please provide images with a scale such as a ruler 

[Fossildude19]

Looks like a tilly bone, to me.

[FossilizedDistraction]

I believe this is a hyperostotic fish bone (Tilly bone). Specifically, I think it’s a hyperostotic neurocranium element. These are a not uncommon find around Cherry Grove Beach and Main Street Beach in North Myrtle Beach, SC.

 

I have close to 3 dozen of these Tilly bones I’ve collected over the past 3 years.

[lisam]

At first I thought it was a tooth but its definitely a fish bone as FossilizedDistraction said.

On 8/23/2023 at 8:17 AM, FossilizedDistraction said:

I believe this is a hyperostotic fish bone (Tilly bone). Specifically, I think it’s a hyperostotic neurocranium element. These are a not uncommon find around Cherry Grove Beach and Main Street Beach in North Myrtle Beach, SC.

 

I have close to 3 dozen of these Tilly bones I’ve collected over the past 3 years.