Dinosaurs died out in this geological era that means "middle life"
[DOC] [TLE] Mesozoic Era: Age of the Dinosaurs - Live Science [PAR] Jan 7, 2015 ... During the Mesozoic, or "Middle Life" Era, life diversified rapidly and ... English 
geologist John Phillips, the first person to create the global geologic timescale, 
first coined ... at the start of the Mesozoic, is defined relative to a particular section 
... elements from the asteroid impact that wiped out the dinosaurs.