Crocodile
First of all, their sex at birth depends on their temperature, not upon sex chromosomes (which they do not have). Eggs are laid in mounds near the water in sand or mud. They are guarded by the female, though she does have to go into the river to eat. The females are unusual for reptiles in that they continue to guard and protect the babies once they are born and in the river. They have a very distinctive behaviour when in the river: if the mother opens her mouth they swim back into it. When danger passes, she opens her mouth, and they swim out. Protection of the babies is one possible explanation of how the crocodiles have been able to survive. Much of this applies to alligators as well.