"This is sad," the bearded man (professor or specialist or rock/fossil guy) says. "A fragment of a paleosomethingsomething shell. Only a fragment." He turns the shell over and over in his hands before holding it up to peer at the surface. Its owner, the family hopeful for an identification, hovers on the other side of the table. The specialist offers a bit of information before turning to another fossil, one that's more intact.

"Ah, now look at this." His eyes light up. "Was this fossil grown in freshwater? No. This was definitely grown in salt water. It's four hundred and fifty million years old, and how did it find its way into the Great Lakes? We were part of the sea at one time." The family nods and stares, clinging to his every word.

Once a year, the U-M Exhibit Museum of Natural History fills its hallways with long display tables staffed with experts in anthropology, geological sciences, zoology, horticulture, archaeology, and paleontology. Then they help people identify stuff they've found — this family's fossils, but also rocks, critters, bugs, and flowers.

The bearded gentleman with the fossils is interesting, but across the aisle are rows and rows of spectacular insect display boxes. George Harmon is manning them, and he showers me with fascinating details of insect life. These magnificent insect specimens are all kept here at the museum — neotropical iridescent butterflies, gigantic (and I mean scary huge) beetles, brilliant dragonflies, cicadas, and katydids. They're loaned out to researchers across the globe and occasionally shown to students but rarely hauled out en masse. ID day is a special event. George interrupts himself to tell a little boy with a magnifying glass about the difference between the katydids and the cicadas. He even imitates their calls.

I try not to look at the spider collection, but I do overhear a gentleman explaining how to collect a spider web. You shoo away the spider, spray black spray paint onto the web, and then walk right through it with paper to gather an impression — from which, I gather, one can identify the spider.

Way upstairs, a geologist isn't sure whether the stone my son retrieved from the lake bottom is a fossil or not. I don't care, really; to me this little rock is a living being. It looks just like a sea lion, with perfectly shaped eyes and a smiling mouth. What I find most fascinating is that this little sea-lion rock absorbs water — sucks it right up. The geologist and I discuss what he calls the "Gaia theory" — that planet Earth functions like a single organism. I tell him I'm glad to hear it.

This year's U-M Exhibit Museum ID Day is Sunday, October 7.

—Charmie Gholson

[Review published October 2007]