Could this be a gryphaea, or is it something else?

[Pleuromya]

Hello, I found this. It looks like a bit of a large gryphaea, but it's probably not.

Sorry there's no scale, it is 6cm long.

I found it in Northamptonshire, UK.

Thanks.

 

[Pleuromya]

[TqB]

I think it is. I've found large Gryphaea lying around in fields in Northamptonshire, many get there in Boulder Clay, derived from the Oxford Clay.

[Pleuromya]

7 minutes ago, TqB said:

I think it is. I've found large Gryphaea lying around in fields in Northamptonshire, many get there in Boulder Clay, derived from the Oxford Clay.

Thanks, I just thought it was an odd shape for one.

[oxford clay keith]

It is part of a Gryphaea.  The slightly concave area with fine parallel lines is part of the hinge area, where the ligament was attached.

[Mark Kmiecik]

On 4/13/2020 at 2:23 PM, Chris Jones said:

Thanks, I just thought it was an odd shape for one.

I thought Gryphaea was the definition of "odd shape". 

[Pleuromya]

2 hours ago, oxford clay keith said:

It is part of a Gryphaea.  The slightly concave area with fine parallel lines is part of the hinge area, where the ligament was attached.

Thanks. 

1 hour ago, Mark Kmiecik said:

I thought Gryphaea was the definition of "odd shape". 

That's true!