The nastiest feud in science (2018)

Why not both? - An Asteroid and a series of colossal Volcanic Eruptions.

>According to this well-established fire-and-brimstone scenario, the dinosaurs were exterminated when a six-mile-wide asteroid, larger than Mount Everest is tall, slammed into our planet with the force of 10 billion atomic bombs. The impact unleashed giant fireballs, crushing tsunamis, continent-shaking earthquakes, and suffocating darkness that transformed the Earth into what one poetic scientist described as “an Old Testament version of hell.”

The the kinetic energy of an impact from massive Asteroid,

would create major pressure differentials in the earths' molten core, causing fracturing of the mantle.

Q.E.D: Dead Dinosaurs et al.