This chart was compiled by Megan Kane using turtle carapace-length data from the Vermont Reptile and Amphibian Atlas Database in June of 2013 and was updated in 2025. The lengths of large adults of each Vermont turtle species were averaged to determine the average adult length. Turtle species were organized by average carapace size, and this average includes the largest 10% for each species. For the 2025 update, we checked to see if the largest individuals for each species had changed (or had been corrected) and adjusted the average adult sizes or record sizes only as needed.
The lengths in the left numerical column are those you would expect for mature adults of the larger sex (usually females) of these species in Vermont. The right numerical column shows the number of individuals that made up the largest 10% of records for that species in the 2013 analysis. The lengths in the middle are those for the largest, reliably-documented turtle of that species from Vermont. Can you document a larger one?
| Length Data for the Longest (Top 10%) Vermont Turtles | ||||
|---|---|---|---|---|
| Measured in inches in a straight line from the front to the back of the carapace | ||||
| Species | Average Carapace Length | Longest Reported in Vermont | Sample Size | Person(s) Who Recorded Longest |
| Spotted Turtle | 4.8 | 4.9 | 2 | Steve Parren et al. |
| Eastern Musk Turtle | 5.0 | 5.3 | 2 | Zach Drummond and Cooper Sacks |
| Painted Turtle | 7.5 | 8.0 | 36 | Chris Dunby |
| Wood Turtle | 7.7 | 8.3 | 3 | Steve Parren |
| Northern Map Turtle | 9.3 | 10.8 | 2 | Rowena Brown |
| Spiny Softshell | 15.0 | 15.6 | 16 | Jed Merrow |
| North American Snapping Turtle | 16.5 | 18.5 | 25 | Kiley Briggs |
