Atmospheric Pressure Reconstruction in the Jurassic and the Mechanism of the Cretaceous-Paleogene Mass Extinction from the Perspective of Atmospheric Increment

Traditional earth science theories mostly regard the Earth's atmosphere as a dynamically balanced or slowly escaping system, attributing the Cretaceous-Paleogene (K-Pg) mass extinction to climate cooling and food chain collapse caused by an asteroid impact. Based on the core axiom that "the Earth's atmosphere is a unidirectionally accumulating incremental body", combined with measured atmospheric mass growth rate, paleontological body size evidence and physical mechanics principles, this study reconstructs the atmospheric pressure at the end of the Jurassic, deduces the instantaneous impact of the asteroid impact on the Earth's atmospheric mass and pressure, and proposes a new extinction mechanism of "physical structure mismatch of large organisms caused by sudden pressure changes". The results show that the sea-level atmospheric pressure at the end of the Jurassic was about 770.66 hPa (only 76.1% of the modern standard atmospheric pressure), and the low-pressure environment provided a physical basis for the survival of giant dinosaurs; the asteroid impact at the end of the Cretaceous brought a large amount of water vapor, gaseous substances and dust to the Earth at one time, leading to an instantaneous increase in atmospheric mass, and the atmospheric pressure jumped from 770.66 hPa to about 951 hPa in a short period of time. The huge static atmospheric pressure resultant force caused physical failure of the respiratory and circulatory systems of large terrestrial and marine organisms, realizing precise extinction divided by body size, while small organisms survived due to their high pressure tolerance threshold. This study perfectly connects astrophysics, atmospheric science, paleontology and geology, constructs a unified explanatory framework for Earth's environmental evolution and mass extinction, achieves a paradigm shift in related fields, and provides a new perspective and quantitative basis for the study of Earth's atmospheric evolution, mass extinction and modern earthquake causes