I live in New Orleans. While doing some digging around the yard, I found what looks to be a fossilized egg. I called a local rock guy who said he doubted that was what I had. But, when I brought it to him he said there was a possibility that it was (he mentioned the membrane-like lines on the bottom as a point of interest). I'm attaching some photos to get some more input. Any insights into what this is would be greatly appreciated!
GeologyRocks