Overview
- The analysis in Biology Letters compared measurements from public photos, scaled by coins, with museum specimens of eight small-mammal species found in Chicago.
- Key proportions in the concrete print did not align with a brown rat, including longer forelimbs and digits than rat measurements would predict.
- Eastern gray squirrel provided the closest match, with fox squirrel or muskrat also plausible, leading the authors to avoid a definitive species identification.
- The team proposes the animal likely fell from a nearby tree onto wet concrete during daylight, consistent with squirrel activity and concrete-pouring times.
- City crews removed the damaged slab in 2024; it now sits under glass at Chicago City Hall as officials consider public display and educational uses.