October 2026 Natural Mystery Answered

We had a tremendous variety of answers for last month's Natural Mystery ranging from insects to crustaceans to herptiles. Everyone who wrote in cued in on the wide trail, close foot placement, and the center drag mark. Congratulations to Local Track & Sign Specialist Maria Wesserle, who did extensive research and took a deep dive into the subtleties of this trail to correctly identify it.

This is the trail of a hatchling freshwater turtle (terrapin, for our South African friends), most likely a snapping turtle (Chelydra serpentina).

I'll turn things over to Maria to share her process and research, then chime in with a quick note at the end:

"Here we see tracks of a small creature crawling out of wet sand and moving into the Mississippi River. Based on this context and the relatively wide trail width in proportion to track size, I am immediately ruling out mammals. The trail looks similar to a hatchling turtle or a crayfish, and this behavior and habitat makes sense for both species. Here are some more details to differentiate the two.

"Crayfish will emerge from sand adjacent to rivers, as seen in this iNaturalist observation by Kim Cabrera (@beartracker). However, note in this photo the many closely-spaced tracks on either side, and the wide drag mark down the middle created by the tail. Sometimes (especially in soft substrates) the drag mark can look more narrow, as in this observation by Kim Cabrera. But in the photos where the drag marks looks like one central line, the tracks are heavily obscured. In photos with clearer tracks, we can see two distinct parallel lines running down the middle of the trail, like a railroad track. This is not present in the natural mystery photo, yet the tracks register quite deeply. When crayfish trails register clearly, you can see distinct groupings of three or four marks, caused by the movement of the four pairs of legs behind their large claws. See for example this iNaturalist observation by Cade Campbell (@cadecampbell). Note again how closely spaced the tracks are, which does not match the appearance of the tracks in the natural mystery photo.

"Now let's compare turtle tracks to the natural mystery photo. In Filip Tkaczyk's Tracks & Sign of Reptiles & Amphibians, he describes a behavior called "dig-ins" and "dig-outs," which are basically when a turtle burrows into or emerges out of a temporary shelter of mud, sand, or leaves. The photo of a musk turtle dig-out on page 329 shows a rounded depression in the mud with paired sets of tracks leading away. And though this doesn't show a dig-out, we can see a trail of a hatchling turtle emerging from soft mud in this iNaturalist observation by Jonathan Poppele (@jonathanpoppele). Note the tail drag and the alternating sets of tracks that look somewhat like a comma or an inverted J in the soft mud. This matches the natural mystery photo!

We are therefore looking at a baby turtle. Though turtles lay their eggs in the spring (usually May or June in our area), it takes about 2-3 months for them to hatch, so they don't appear until fall. I don't think we are seeing evidence of the act of hatching in the photo, as turtles in our area move upland to lay their eggs, and this is very close to the river.

In terms of species, I think this is probably snapping turtle, as they are most likely to leave a tail drag. Furthermore, upon closer examination of the dig-out, I believe you can see the leading edge of the diamond-shaped plastron (see this photo by Wayne T. 'Tom' Helfrich). I don't know of any other turtles in our area with such a narrow plastron."

Thanks to Maria for this amazing analysis. As for the species ID, we can also consider the animal's posture while walking in deep mud. The diamond-shaped plastron that Maria mentions allows snapping turtles to orient their legs nearly straight down--raising their bodies higher off the ground. Pond turtles typically show plastron drag, especially in (proportionally) deep mud like this. For a nice comparison of plastron shape and tail length in hatchling turtles, check out these iNaturalist observations:

• Hatchling snapping turtle by Danielle Kathryn (@awildplantlady)

• Hatchling painted turtle by @funky_commelina

Congratulations again to Maria for sorting out this challenging Natural Mystery. And thanks to everyone who wrote to share their ideas and their process.