Probably not an egg

[ranger_kate]

A gentleman asked for help identifying this and told me he found it near Mt. Pleasant, TX. Based off images on the internet he thought it might be a fossilized egg. He was NOT willing to break it open. I forgot to include something in the photo for scale, but it's about 5" across the long side. He's asked me to call him when I find out more information.

 

My first thought was a geode. Members of the Dallas Paleontological Society's Facebook group said an iron or limonite concretion.

 

What features differentiate this from a fossilized egg?

 

 

[Kane]

I'm thinking it is not a fossilized egg.  

 

The "rind" seems a bit too thick and lacking in texture. This seems to be a nodule or concretion. There are parts of the "rind" that seem to blend with the interior of the piece, which may also be a telltale sign it is not a fossil egg. The fact that the exterior and interior seem to be about the same colour and roughly the same texture also points to concretion. 

[abyssunder]

I agree. It's not an egg. A concretion might be a good ID for it.

[ranger_kate]

Thank you, Kane for the reasons why it's not an egg! I feel more comfortable now explaining that it's probably a concretion.