Devonian Bivalve? from Paulding

[connorp]

I found this small "clam" last week at the Paulding Community Fossil Garden in Ohio. This specimen was found loose but likely came from the Silica Shale (Middle Devonian). It has a bivalve-y look, similar to the bivalve Mytilarca cordata which is known from here. However, the valves are not symmetric about the hinge line, although @Peat Burns suggested it could be a deformation. Any ideas are appreciated.

 

[Tidgy's Dad]

Pretty sure that's a bivalve. 

[Ludwigia]

+1 for deformed bivalve. I've seen plenty like this in the Jurassic. Was it deposited in clay or marl?...aha...Silica Shale...good chance for deformation.

[minnbuckeye]

Looks similar to  Mytilarca cordata. I found this one at the Lafarge Quarry site in Paulding. This species is distinctively triangular. Can't tell from your pictures if it is. Otherwise @Peat Burns is the Paulding expert! He likes to prove me wrong. LOL

[connorp]

1 hour ago, minnbuckeye said:

Looks similar to  Mytilarca cordata. I found this one at the Lafarge Quarry site in Paulding. This species is distinctively triangular. Can't tell from your pictures if it is. Otherwise @Peat Burns is the Paulding expert! He likes to prove me wrong. LOL

 

Yep, triangular is a word I would use to describe mine. Thanks.

[FossilDAWG]

I'm not sure it's all that deformed.  I think that's their actual shape.  Have the piles been replenished in a while?  I stopped by about this time last year, and it was obvious the piles had been there for some time.  Still found a nice diversity of brachiopods, corals, and trilobits though, so I was quite happy.  A squished thorax+pygidium was the closest I got to anything complete unfortunately. 

 

Don

[Peat Burns]

2 hours ago, minnbuckeye said:

Looks similar to  Mytilarca cordata. I found this one at the Lafarge Quarry site in Paulding. This species is distinctively triangular. Can't tell from your pictures if it is. Otherwise @Peat Burns is the Paulding expert! He likes to prove me wrong. LOL

 

Mytilarca cordata was my first thought when connorp showed it to me in a PM.   It would have to be a juvenile, though.  I've never seen one this small.  I'm going to dig into my literature tomorrow and see if there are any taxa that are a better match.  Hopefully it's something different so we can add another taxon to the site list 

[connorp]

26 minutes ago, FossilDAWG said:

I'm not sure it's all that deformed.  I think that's their actual shape.  Have the piles been replenished in a while?  I stopped by about this time last year, and it was obvious the piles had been there for some time.  Still found a nice diversity of brachiopods, corals, and trilobits though, so I was quite happy.  A squished thorax+pygidium was the closest I got to anything complete unfortunately. 

 

Don

I don’t think so. I don’t think they have been in a while, if ever. But there’s still a lot to be found. I found basically everything but a complete trilobite on this trip – a gastropod, one or two bivalves, and a placoderm armor plate were the highlights.

[Peat Burns]

37 minutes ago, FossilDAWG said:

Have the piles been replenished in a while?

They added several new rows of material a year or two ago (may be closer to two years.  I lose all sense of time as I get older).  The new material is closest to the parking lot and not yet overgrown with weeds.  The original material is getting pretty overgrown except the first row (furthest from the parking lot) which has a lot of large chunks of hard limestone.  The original material seemed to yield more enrolled trilobites than this new stuff.  I guess it depends on what members are excavated and deposited.  I wish they would feather-out the original stuff with a dozer.  I'm sure there is still a bunch of goodies buried in those piles.

[Jeffrey P]

On 7/1/2020 at 9:58 PM, Peat Burns said:

Mytilarca cordata was my first thought when connorp showed it to me in a PM.   It would have to be a juvenile, though.  I've never seen one this small.  I'm going to dig into my literature tomorrow and see if there are any taxa that are a better match.  Hopefully it's something different so we can add another taxon to the site list 

I'm thinking that is Gosselettia triqueter, though a rather small one. Mytilarca is more oval-shaped. I found a Goselettia there last month which surprised me. I've only seen them from two sites in Central N.Y., both very close to one another, both the same formation- The Oaktacreek Formation Mottville Member. I checked the species list for the Silica Shale and Gosselittia was on it.