Evolution. Did an impact trigger the dinosaurs' rise?
Kerr
Richard A
RA
D000818:Animals; D005075:Biological Evolution; D025061:Dinosaurs; D017753:Ecosystem; D029624:Ferns; D005580:Fossils; D019015:Geologic Sediments / Q000737:chemistry; D007495:Iridium / Q000032:analysis; D019110:Meteoroids; D018543:Minor Planets; D009656:North America; D010414:Pennsylvania
D007495:Iridium