The Chicxulub Impact and the K-Pg Mass Extinction

Approximately 66.04 million years ago, a carbonaceous asteroid measuring an estimated 10 to 14 kilometers in diameter struck the carbonate-rich continental shelf of the Yucatan Peninsula in modern Mexico at an angle of roughly 45 to 60 degrees.

The Cascade of Global Cataclysms

1. Kinetic Blast and Thermal Radiation: The impact released energy equivalent to approximately 100 million megatons of TNT, triggering regional thermal pulses that ignited global wildfires within hours.

1. The Impact Winter: Billions of tons of vaporized sulfur-rich anhydrite, soot, and pulverized dust were propelled into the stratosphere, blocking sunlight and shutting down photosynthetic primary productivity in both terrestrial and marine ecosystems for multiple years.

1. Selective Survival: Small ectothermic vertebrates with low metabolic requirements (such as crocodilians, turtles, and lizards), burrowing organisms, and toothless neornithine birds capable of feeding on seeds and detritus survived, while all non-avian dinosaurs succumbed.