I found these today in a box I packed away 40 years ago

[Ssherrick]

I found these today in a box of fossils from my collection that I had in the 1970's.  Other fossils in the box were mainly trilobites, crinoids and brachiopods.  At one time,  I had several thousand fossils, primarily from Ohio, Alaska and Utah.  I personally collected 100% of the collection,  so these fossils most likely came from oneof these states.   

 

Any help would be appreciated.   Thank you.

 

  

[Tidgy's Dad]

Internal mould of a bivalve. 

[Miocene_Mason]

These look like steinkerns of Cucullaea gigantea which come in bucket loads out of a certain place in Maryland.  Late Paleocene Aquia formation.

[Wolf89]

My first thought was steinkern too. 

[fossilnut]

I have also found them on the beach at North Myrtle Beach, SC where at times you can find a number of them. By the species name, they were comparatively large in size with some of them over fist size. Anyone know more about them? They must have formed large groupings. Be interested to know. Thanks

[Miocene_Mason]

4 minutes ago, fossilnut said:

I have also found them on the beach at North Myrtle Beach, SC where at times you can find a number of them. By the species name, they were comparatively large in size with some of them over fist size. Anyone know more about them? They must have formed large groupings. Be interested to know. Thanks

I don’t know much about them but the body design must have worked well, I have found similar fossils in Maryland’s Devonian and Miocene. Not the same type, but similar build.

[Plax]

all clam steinkerns shaped like this are not Cucullea steinkerns. I do believe the common ones at Myrtle Beach are Cucullea vulgaris though. Cucculea gigantea is found in the Aquia formation in MD and VA. Here's a good reference that shows the shell preserved so you can see the clam that enclosed the sediment.

https://pubs.usgs.gov/pp/1346/report.pdf

  Other "deep dish" clams have similar steinkerns such as Ark Clams.

 

[Ssherrick]

This narrows down when I found them.  Thanks for the replies.  I had done a collecting trip to the area around Calvert Cliffs in Maryland and Patuxet River Navel Air Station in the late 70's.  That also explains the crinoids that was packed with them. Thank you. 

[Miocene_Mason]

19 minutes ago, Ssherrick said:

This narrows down when I found them.  Thanks for the replies.  I had done a collecting trip to the area around Calvert Cliffs in Maryland and Patuxet River Navel Air Station in the late 70's.  That also explains the crinoids that was packed with them. Thank you. 

Crinoids are not common at the cliffs or the patuxent to my knowledge...

[abyssunder]

What is clear to me, there are nice bioeroded steinkers.

[Innocentx]

I've heard these called heart clams.

@abyssunder Yes the feeding traces are quite interesting as well.

[goatinformationist]

3 hours ago, WhodamanHD said:

I don’t know much about them but the body design must have worked well, I have found similar fossils in Maryland’s Devonian and Miocene. Not the same type, but similar build.

 

And they can be found all around Murrels Inlet in SC

[Ssherrick]

My crinoids must have come from somewhere else.   I know that I found a lot of them in Ohio.  Sometimes it seems that my memory will become as extinct as the fossils we collect. 

[Herb]

Ohio seems the likely place for the crinoids.

[fossilnut]

17 hours ago, Innocentx said:

@abyssunder Yes the feeding traces are quite interesting as well.

Do you have pictures or a reference for these? I would be very interested in seeing what they look like. Thanks

[fossilnut]

17 hours ago, goatinformationist said:

And they can be found all around Murrels Inlet in SC

Hi My wife and I long retired go to NMB, SC each late fall for a couple of weeks and hunt for fossils on the beach there. We shop and eat at Murrels inlet but never thought of fossiling there. Can you give me any more info on fossiling there? Thanks

[KimTexan]

We have very similar ones here in North Texas only they are light gray to tan. I have some with worm or snail traces.

They are called deer heart clams here. I’m not sure if the genus species name though.

[Plax]

22 minutes ago, fossilnut said:

Hi My wife and I long retired go to NMB, SC each late fall for a couple of weeks and hunt for fossils on the beach there. We shop and eat at Murrels inlet but never thought of fossiling there. Can you give me any more info on fossiling there? Thanks

search this forum as there are many references here.

[Innocentx]

1 hour ago, fossilnut said:

Do you have pictures or a reference for these? I would be very interested in seeing what they look like.

You would think there'd be easily accessible information about these borings as they seem ubiquitous to fossils of this clam in that area. Maybe I'm doing the search wrong but can't come up with it.

[fossilnut]

3 hours ago, Innocentx said:

You would think there'd be easily accessible information about these borings as they seem ubiquitous to fossils of this clam in that area. Maybe I'm doing the search wrong but can't come up with it.

Oh I totally misinterpreted @abyssunder's comment. It was about the feeding traces ON the steinkerns which are clearly evident. I was thinking it meant feeding traces left by the bivalves which would have been unusual to say the least.  But who caused the borings on the bivalves would be of interest as well.

[goatinformationist]

6 hours ago, fossilnut said:

Hi My wife and I long retired go to NMB, SC each late fall for a couple of weeks and hunt for fossils on the beach there. We shop and eat at Murrels inlet but never thought of fossiling there. Can you give me any more info on fossiling there? Thanks

 

My sister in-law lives there and has piles of these things from every earth moving building site in the city.  Sorry but that is all that she told me.  Good luck hunting.

[fossilnut]

14 minutes ago, goatinformationist said:

 

My sister in-law lives there and has piles of these things from every earth moving building site in the city.  Sorry but that is all that she told me.  Good luck hunting.

Thanks for that info.

[Bronzviking]

Here's some interesting info:

 

"Cucullaea Gigantea, a now extinct bivalve from the Paleocene ranging in age from 58.7 – 55.8 million years old. These guys were infaunal suspension feeders, meaning they burrowed into the seafloor and strained their food from the water. By now the shell had completely eroded away, but what was left is a perfect mold of the interior composed of the greenstone. When this creature died a small opening was left so that sediments could fill in and later harden into rock. As time passed the more easily weatherable shell went away and all that remained was the more durable greenstone. C. Gigantea is about twice the size of its relatives such as Cucullaea recendens averaging about 8 – 14 cm in length, while C. Recendens averages 5 – 8 cm. Finding marine fossils in a Maryland creek bed also shows that it was once a marine environment."

 

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