This is something I wrote a while ago, this was in Northern Illinois. A true story, and told as how I remember it. They looked similar to the ones in the original post here, but more "oval" with no protruding parts to them.
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If I only had a time machine....
Back when I was around 10 years old or so, my cousin Matt and I were at his place for the day. It was a nice summer day and we were out by the pasture, probably making plans to build a fort of some kind. We were sitting by this huge old oak tree that was dying, and we were prying with some sticks into the ground at the base of it.
Out comes this weird little "statue" of some kind, approx. 7 inches tall, with a flat bottom and rounded top - in the image of a person. We were shocked and kept digging. Four more of these come out for a total of five, all made similar but a little different. All were possibly made by the same artisan but of different people. It was just so shocking that we'd happen to pop them out right there, it kind of freaked us out a little. I wanted to bring them back to his house but he didn't want to, he was afraid we'd get into trouble for some reason. I wanted to bring one of them back to ask his dad what he thought, but it was getting late and we reburied them and decided we'd ask another day.
It was all I could think about for days, and the next weekend my mom took me back over there. During that time, Matt's dad had taken a large tractor and graded the area, pushing the large dead trees into a huge pit that was used as a dump. The ground near the oak tree where our statues were, was graded down about four feet. I was very depressed about it. To this day they must still be there somewhere, whether buried 20 feet deep in the dump itself or spread in the surrounding dirt.
I have discussed this with Matt, he remembers "something" about this - but not much. He was around 8 years old at the time, and this was well over 35 years ago.