Sea reptiles become extinct > Mammals appear > birds appear.
Marine reptiles started to disappear around the Mesozoic Era. The massive extinction of ichthyosaurs, nothosaurs, and placodonts started at the middle-late Triassic. Early mammal population appeared 180 million ago with the monotremes, a species of animals that lay eggs. 168 million ago appeared the Epidexipteryx, a half-feather dinosaur that could not fly but is considered the first kind of bird.
The right answer for the question that is being asked and shown above is that: "Sea reptiles become extinct > Mammals appear > Birds appear." The list below describes some events which took place at different periods in the geologic time scale. This is the <span>order of the events from the earliest to the most recent</span>
