What 6 groups of organisms survived the cretaceous tertiary extinction?

The six groups of organisms that survived the Cretaceous-Paleogene (K-Pg) extinction event include mammals, birds, reptiles (specifically some lineages of lizards and snakes), amphibians, fish, and certain invertebrates like insects and crustaceans. These groups were able to adapt to the drastic environmental changes that followed the event, which was primarily caused by a massive asteroid impact and volcanic activity. Their survival laid the groundwork for the evolution and diversification of species in the subsequent eras.