We are lucky to have birds!

The K-Pg Event Almost Killed the Birds

In this article a researcher from Bath University says that only a small number of ancestral bird species survived the asteroid impact that did for the dinosaurs.

All the tree living ones died; probably because all the trees were destroyed! Only five bird lineages survived and they were all ground dwellers.  There is a lot more in the original paper, but this is far from my (limited) areas of expertise so I will leave criticism of the evidence to others.

The tinamous is one of the most similar living birds to those that survived the K-Pg. Daniel J Field, Author provided