What is this? Thingies found on top of cold compost.

I'm not really sure if this is the best place for this post, please move this to the proper Forum if I'm in the wrong place.

I found these odd little, nodules? On top of a pile of random cold composted materials*. What are they? I first thought they might be fruit pits from the tree that overhangs it but I don't think so. Because there seem to be clusters.


*I did some work today in the barely tended backyard.
I was clearing out some of the random weeds growing in a former raised bed. The bottom had been filled with sticks and grass clippings and leaves and all kinds of random organic matter in the beginning. With wood chips and soil pockets on top that held the plants. It's been left and ignored for several years now. I should probably scoop it out and relay the bottom and put some sunchokes in it. It's probably good stuff.

Hm! Well somebody's been playing in your slow compost.

Can you cut a nodule in half and post a photo?

That looks like mushrooms to me.  There are hundreds of varieties.

Also, mushrooms would love that sort of organic material.

Of course, it is hard to say what they are without seeing them in person. 

Are they soft like mushrooms or hard as Douglas suggested, nodules?