Rapid burial by volcanic ash is rather easily comprehended; by other means, not so much.
The massive, incomprehensibly rapid burials of trilobites comes to mind, preserving gazillions of their remains intact over wide areas, their structures amazingly intact, even in some instances their chitinious exoskeletons not mineralized, while fossil remains of their evolutionary predecessors elude us, denying us clues as to the developmental steps leading to the amazingly (and that word fails to render descriptive justice) complex trilobite eye .
Whole communities of ape-like creatures may have been killed in volcanic disasters that struck East Africa 18 million years ago... the once active volcano Kisingiri... contained fossils of what is believed to be a forerunner of humans called Proconsul... they may have been caught by a pyroclastic flow... the abundance of the hominoid fossils may represent "death assemblages" -- whole populations wiped out simultaneously by "glowing cloud" eruptions.
