Echinoid round rock

[JulianoLPD]

Me again here guys.

 

Well, I just stepped on this fossil on that auction website and it caught my attention because of the round shape of the rock.

As a newbie that seemed weird to me.... Would an echinoid fossil have this round aspect (Third pic speaks for what I mean)?

(I don't know if I'm clear on what I'm meanbut somehow it seems fake to me...)

 

Can anyone give more information on how to detect the fakes?

Thanks in advance

[Tidgy's Dad]

Looks real to me.

Nice specimen. 

[Seguidora-de-Isis]

I agree with our dear friend Tidgy's Dad. Do not worry. This Echinoid is real.

 

You are accustomed to walk on the beach and observe these beautiful flattened echinoids in the sand...

 

 

But just as there are currently several species of echinoids in the past was not so different ... We can find echinoids fossil flattened with a beautiful crown of King:

 

 

Round Thorny

 

 

Among a multitude of other species and more bizarre formats possible...

 

 

 

If this echinoid you posted here was discovered in the region of Agadir in Morocco, I do not rule out the possibility of being a Toxaster peroni.

 

[JulianoLPD]

Thank you both guys.

 

Learning a lot from you! 

[caterpillar]

Take a look

 

https://www.google.com/search?q=toxaster&client=firefox-b&source=lnms&tbm=isch&sa=X&ved=0ahUKEwj95enf_IbgAhUQCRoKHVYODmcQ_AUIDigB&biw=1704&bih=905

[DPS Ammonite]

1 hour ago, caterpillar said:

Take a look

 

https://www.google.com/search?q=toxaster&client=firefox-b&source=lnms&tbm=isch&sa=X&ved=0ahUKEwj95enf_IbgAhUQCRoKHVYODmcQ_AUIDigB&biw=1704&bih=905

I love it: thanks to Google ad software, there are pictures of toasters for sale at the top of the page. We want to see Toxasters for sale not toasters.

[Wightlight]

One of the reasons it's so round is that it's a "steinkern" (stone core) fossil. It's created by the echinoid shell getting filled with sediment, which consolidates and creates a stone imprint of the inside of the shell, while the outside dissolves away. So there's no spiny shell or anything left.

[FossilDAWG]

1 minute ago, Wightlight said:

One of the reasons it's so round is that it's a "steinkern" (stone core) fossil. It's created by the echinoid shell getting filled with sediment, which consolidates and creates a stone imprint of the inside of the shell, while the outside dissolves away. So there's no spiny shell or anything left.

I disagree with this statement.  The slit-shaped openings in the ambulacra ("petals") go into the fossil; they would stick out in a steinkern.  Same for the pores in the genital plates.  Also the tubercles that were bases for the spines stick out; they would not be present at all on the inside of the test (shell) and so they would be absent on a steinkern.  The surface we see is the surface of the echinoid test, not the surface of an internal filling. 

 

Don

[Wightlight]

11 minutes ago, FossilDAWG said:

I disagree with this statement.  The slit-shaped openings in the ambulacra ("petals") go into the fossil; they would stick out in a steinkern.  Same for the pores in the plates.  Also the tubercles that were bases for the spines stick out; they would not be present at all on the inside of the test (shell) and so they would be absent on a steinkern.  The surface we see is the surface of the echinoid test, not the surface of an internal filling. 

 

Don

I gotta admit that I'm unfamiliar with the type of echinoid in question and based it on the echinoid flint steinkerns we get here in Denmark (Galerites and the like) where the ambulacra impression is inward. My bad!

[FossilDAWG]

That is a nice steinkern you have there .  

 

Don

[sixgill pete]

@JulianoLPD thats is a gorgeous echinoid. If it comes with all the needed info and the price is right i would say get it.

@Wightlight that is indeed a gorgeous steinkern. 

[JulianoLPD]

Thank you all guys!

 

Very informative answers.

Quote

2 hours ago, sixgill pete said:

@JulianoLPD thats is a gorgeous echinoid. If it comes with all the needed info and the price is right i would say get it.

As for the price, since I'm a total newbie, I can't say if it is right... 
What would you say is a fair deal?

 

 

[sixgill pete]

4 minutes ago, JulianoLPD said:

Thank you all guys!

 

Very informative answers.

 

Only you can decide if the price is right for you. 

[JulianoLPD]

I understand! Thanks!