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How did the Chicxulub asteroid impact disrupt the dinosaur food chain?

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Illustration showing various dinosaur species drawn to scale and grouped by geologic era: Late Cretaceous, Early Cretaceous, Jurassic, and Triassic. Dinosaurs range from large species like Brachiosaurus and Tyrannosaurus to smaller ones like Velociraptor and Compsognathus, with a human silhouette included for size comparison. Measurement bars at the bottom indicate 1 meter and 3 feet for scale reference. — dinosaur A selection of dinosaurs grouped by the geologic interval in which they lived.

The Chicxulub asteroid impact disrupted the dinosaur food chain primarily by triggering a global environmental collapse that halted photosynthesis.12

When the asteroid struck Earth 66 million years ago, it ejected an enormous volume of rock, dust, and debris into the atmosphere. This material enshrouded the planet, blocking out sunlight for months or potentially years. The resulting lack of light caused green plants to die, which led to the subsequent collapse of ecosystems and the food chain. As primary producers vanished, herbivores lost their food source, which in turn led to the starvation and extinction of their predators and scavengers.1342

Additionally, the impact caused widespread wildfires and significant climatic cooling, with global temperatures potentially dropping by as much as 28 °C (50 °F). While some species, such as small mammals and those living in freshwater environments, were better equipped to survive these harsh conditions, the disruption proved fatal for the majority of dinosaur species.42