What form of reproduction did the first animals on land use*? Were they hermaphrodites, or did they have male and female sexes? [Is there a proper term for sexual separation in a species?]
Were any land species believed to have evolved from hermaphrodite ocean species (that crossed to land on roughly the same geological time periods that land creatures first evolved)?
*I know that 'first on land' is a complicated concept itself, since it could mean first creatures be able to survive on land at all, first to freely travel between land and water, or first to only live on land, or anywhere in between. I assume all three categories were sexual though?