The Triassic–Jurassic extinction represents a significant boundary event in the geologic record, marking a profound biological crisis that dramatically altered global ecosystems. This mass extinction is primarily characterized by a severe reduction in biodiversity across both marine and terrestrial environments. Scientific consensus points to large-scale environmental stressors, such as massive volcanism and associated rapid climate change, as the driving forces behind the global collapse of established biotas. The resulting ecological upheaval caused a major restructuring of faunal assemblages, allowing surviving lineages to radiate and giving rise to new dominant groups that defined subsequent periods of life on Earth.