If a big meteor hit there would be a lot of damaged living beings in the vicinity, but on the other side of the earth there would be slow death. We know that the dinosaurs all died. However small mammals and reptiles, and even birds survived. Crocodiles and alligators hide under embankments. Turtles have thick shells. Birds have feathers. Small mammals live in underbrush and burrows. Small lizards and snakes live in cracks and crevices. So one theory I have is that the bolide strike destroyed the ozone layer and large animals died of skin cancer and disease. Why did the small dinosaurs also die? Perhaps disease that was especially deadly to dinosaurs. Also why did the great marine reptiles die as well, in fact do we know if they did die at that time?
The temperature went up, the water supply vanished, the Sun vanished, food vanished. Smaller critters would need less of everything. The megafauna died off. Marine life also changed dramatically — although that used to be denied, and that particular denial may still be clinged to by the residue of gradualist morons who claim that the dinos *gradually went extinct* over millions of years. It got harder and harder to find a mate on the D-Date website, apparently, until there was only one left. /s
You’ve put your finger on a great detail — if a massive flood of neutrinos killed off the dinos, why would it not kill off everything on, in, under the Earth, regardless of which side of the globe — neutrinos, we’re assured, can pass right through the entire Earth.