Some scientists believe that the slow repositioning of Earth's
landmasses lead to the extinction of dinosaurs. Convection
currents within the Earth's mantle caused landmasses to drift,
collide, and eventually heave upward. Ocean currents were
redirected and sea levels throughout the planet dropped. For
example, the interior seaway, which once divided North America,
drained away as the Colorado Plateau rose thousands of feet into
the air. Without shallow seas like this one, climates became
cooler and drier. Such climatic change resulted in new
ecosystems that could not provide enough biomass to support
dinosaur life.
Which scenario leading to the extinction of the dinosaurs is NOT
discussed in the two passages which discuss possible theories?
A) a flood
B)
an asteroid
unstable earth
D)
erupting volcanoes