How long have leatherback sea turtles roamed our planet?

Leatherback sea turtles have roamed our planet for 100 million years.

Explanation:

Leatherback sea turtles have a lifespan of about 50 years, these live in oceans and are world's largest turtles about 2m long in length. They also migrate huge distances. These big reptiles have been on our planet earth for a really long time of about 100 million years. These turtles are carnivores in nature i.e they feed on other sea animals like jellyfish. These have been on the planet since dinosaurs existed. For now, these turtles are critically endangered and require conservation and care.

answer; /// i do believe that its napolean's conquest of spain;

north atlantic treaty organization.