I wonder why the crocodiles survived.
My guess is that everything that survived was either a burrow nester, no mammal larger that a house cat survived, many birds, some are also burrow nesters, or buried its eggs as do turtles and snakes, or placed them in large, often wet, debris piles like crocodiles.
The Chicxulub impact was worst possible case, a shallow water impact. Imagine a 90 mile wide white hot crater with sea water flooding in from all sides. It would be like a rocket engine blasting steam and entrained air into space.
The world could have lost half its air into space!
Burrow dwellers are accustomed to low oxygen environments. Burrow dwellers are protected from surface fires and the rain of red hot debris. Surface dwellers, not so much...
“I wonder why the crocodiles survived.”
Keith Richards and cockroaches survived this asteroid.