They genuinely do house organisms found nowhere else, products of long isolation and evolutionary divergence.

The landscape genuinely does feel, to visitors, like somewhere that operates under different rules than the familiar world.

The “lost world” phrase is also resonant with something that the scientific description of tepui biology makes more rigorous: the idea that evolution is not a single global process moving all life forms in the same direction, but a multitude of local processes, each working with the organisms available in a specific place under specific conditions, producing outcomes that can be radically different from what the same starting organisms would have produced in different conditions.

The Roraima bush toad did not evolve direct development because evolution was “trying” to produce a toad that could dispense with a tadpole stage.