In turtles, females are usually larger - probably relating to fecundity. Males do not compete strongly for females. As expected, more females are produced at high temperatures. In crocodilians and some lizards, males are larger, probably due to intense intra-sexual competition among males for access to females. Here, as expected, males develop at higher temperatures.
Exceptions are instructive.
For example, snapping turtles produce more males at high temperature. Here, as is crocs, the males are quite aggressive and fight for females. We have been discussing situations where animals might change their primary sex ratio. Another way to play this game is for an individual to change sex. Let me give you three different kinds of hermaphroditism and the circumstances that might favor each.