Reddit reviews Solnhofen: A Study in Mesozoic Palaeontology

This book has a faunal list accurate to the time of publication. A few new species have been described since, though.

Sea life survived because the water itself was stratified, i.e. there was a surface layer that was oxic and warm and a deeper layer that was anoxic and cold, and these layers did not mix due to temperature-dependent differences in density. This is typical of deep lacustrine and some lagunal aquatic systems. Animals that traversed the boundaries between these layers would have quickly died.