Observations and measurements on the North American Wood Turtle: Glyptemys (Clemmys) insculpta with notation of two different phenotypes – A 1985 study
Courtesy of POLYPHEMOS (2004)
Typical dimensions of Glyptemys insculpta
Based on eight live specimens
Research conducted 1985
Carapace length Carapace width Head width Carapace- Plastron length("Carastron index") inches / centimeters
Males -Yellowlegs phenotype
7 3/4 19.8 5 9/16 14.2 1 5/16 3.5 11/16 1.6
7 5/16 18.3 5 1/2 13.9 1 7/16 3.6 6/16 1.0
Males -redlegs phenotype
7 1/16 17.8 5 4/16 13.6 1 3/16 2.8 9/16 1.3
7 14/16 19.9 5 12/16 14.4 1 4/16 3.2 1 5/16 2.2
Females -yellowlegs phenotype
6 11/16 17.4 5 9/16 14.3 1 1/16 2.7 -1/16 -0.2
7 3/16 18.3 5 11/16 14.4 1 3/16 2.9 -2/16 -0.3
Females -redlegs phenotype
7 4/16 18.5 5 1/2 13.9 1 2/16 2.8 4/16 0.7
7 4/16 18.5 5 9/16 14.0 1 3/16 2.9 5/16 0.9
Research and observations were conducted in 1985 by Brian L. Schnirel on Glyptemys insculpta. Live specimens were acquired and it was noted at that time that two distinct phenotypes were in evidence with this species. The different color aspect of this species has been mentioned by Pope (1938) and Harding (1997).
The Redlegs (Pope, 1938) phenotype has reddish – orange skin and a yellow ringed iris (In most cases). The Yellowlegs (Schnirel, 1985) phenotype has yellowish skin and no yellow iris ring. The eye is completely black.
Both types of Glyptemys insculpta were measured for carapace and plastron length, head width, and difference in length between the carapace and plastron (‘carastron’ index). Two of these measurements (the head width and the ‘carastron index are linked with sexual dimorphism of Glyptemys insculpta. The two varieties were tested using variations of the Tinklepaugh labyrinth experiment, Yerkes space reaction experiment, and mirror association experiments. Photographs were taken at this time on these two phenotypes and were included in this report.
Contributed by Brian – LCRC.
Accepted on October 8, 2007.