Paleontology.  Whiff of gas points to impact mass extinction.
R A
RA
Kerr
D000818:Animals; D001128:Argon / Q000032:analysis; D002244:Carbon / Q000032:analysis; D018534:Earth, Planet; D005580:Fossils; D037741:Fullerenes; D019015:Geologic Sediments / Q000737:chemistry*; D006371:Helium / Q000032:analysis; D007554:Isotopes; D019110:Meteoroids; D018543:Minor Planets; D010163:Paleontology
D037741:Fullerenes; D007554:Isotopes; D006371:Helium; D001128:Argon; D002244:Carbon; C069837:fullerene C60