TABLE 4.--A Summary of Sexual Dimorphism in _Terrapene ornata_. ============+============================+============================== CHARACTER | MALES | FEMALES ------------+----------------------------+------------------------------ Head | Snout truncate in lateral | Snout relatively round in | profile, top of head and | lateral profile; front of | front of maxilliary beak | maxillary beak not forming | forming an angle of nearly | right angle with top of head; | 90°; head yellowish green | head dark brown, distinct | to bluish green; markings | pale markings on head and | on head and neck reduced; | neck; head commonly spotted | head never spotted dorsally| dorsally (Pl. 25, Figs. 5 | (Pl. 11, Figs. 7 and 8). | and 6). ------------+----------------------------+------------------------------ Iris | Red | Yellowish brown ------------+----------------------------+------------------------------ Hind legs | Heavy and muscular; first | Not especially heavy or | toe turned in, thickened, | muscular; first toe, if | and widened (Fig. 21). | turned in, never thickened | | or widened (Fig. 21). ------------+----------------------------+----------------------------- Forelegs | Centers of antebrachial | Centers of antebrachial | scales bright orange or | scales yellow, pale orange, | red. | or brown. ------------+----------------------------+----------------------------- Carapace | Relatively lower, length | Relatively higher, length | contained in height (48 | contained in height (94 | specimens) .58 times | specimens) .50 times | (± .005[sigma]m, range, | (± .005[sigma]m, | .50 to .69). | range .44 to .60). ------------+----------------------------+------------------------------ Plastron | Ordinarily slightly | Flat or convex, never (hind lobe)| concave. | concave. ------------+----------------------------+------------------------------ TEMPERATURE RELATIONSHIPS Tolerances to environmental temperatures, and reactions to thermal stimuli influence the behavior of ectothermal animals to a large extent. _Terrapene ornata_, like other terrestrial reptiles inhabitating open grassland, is especially subject to the vicissitudes of environmental temperature. Other species of turtles living in the same area are more nearly aquatic and therefore live in a microhabitat that is more stable as regards temperature.