New Jersey Cretaceous ID help

[frankh8147]

Greetings!

 

I found this today in a Cretaceous stream in Monmouth County, NJ. My best guess would be some type of enchinoid, but I'm really not sure so I'm wondering if anyone knew what it was. I believe it to be from the  Wenonah Formation. 

 

As always, any help is greatly appreciated!

-Frank

 

[Fossildude19]

Neat find, Frank! 

Looks echinoid to me! 

I think the triangular shapes on the top are the Aristotle's lantern.   

Can't help any further than that, though.

 

John's website has some pictured - don't know if that htelps. 

[Peat Burns]

30 minutes ago, Fossildude19 said:

Neat find, Frank! 

Looks echinoid to me! 

I think the triangular shapes on the top are the Aristotle's lantern.   

Can't help any further than that, though.

 

John's website has some pictured - don't know if that htelps. 

+1

[Al Dente]

It is the oral surface of an echinoid. The five triangular structures are part of the peristome. Aristotle lanterns are found in regular echinoids, this looks like an irregular echinoid, maybe something similar to Hardouinia.

[frankh8147]

That's great! Thank you everyone,  I really appreciate the help! 

[erose]

Great fossil. Echinoids are rare in the brooks.

[Tidgy's Dad]

Nice find! 

And rather pretty too! 

[frankh8147]

6 hours ago, erose said:

Great fossil. Echinoids are rare in the brooks.

Thanks guys! And yeah, I was hoping it was an enchinoid but haven't seen many come from there so I didn't have much to compare. Appreciate all the help again!

 

[Coco]

On 03/05/2018 at 11:53 PM, Al Dente said:

Aristotle lanterns are found in regular echinoids

Are you sure it is only found in regular sea urchins ? Clypeaster and several flat sea urchins have teeth, I suppose they have Aristotle lanterns too. Or then it has another name than I don't know...

 

But I agree with you, it is not aristote's lantern, but probably an intern part of sea urchin.

 

Coco

[Al Dente]

20 minutes ago, Coco said:

Clypeaster and several flat sea urchins have teeth, I suppose they have Aristotle lanterns too. Or then it has another name than I don't know...

You are right, sand dollars also have a modified version of an Aristotle’s lantern. It seems odd to me that the sand dollars retained this structure while other irregular echinoids had no need for it.