Q 01/05

Roughly how many years ago did the extinction that wiped out the non-avian dinosaurs occur?

A) 6 million

B) 1 billion

C) 66 million

D) 250 million

Answer · why

C) 66 million

It ended the Cretaceous and the Mesozoic and opened the Cenozoic era.

Q 02/05

What proportion of plant and animal species on Earth are estimated to have died in the K-Pg extinction?

A) About a quarter

B) About one-tenth

C) About three-quarters

D) About half

Answer · why

C) About three-quarters

Marine fossils suggest 75% or more of species vanished.

Q 03/05

By what earlier name was the K-Pg mass extinction commonly known?

A) The Great Dying (Permian)

B) The K-T (Cretaceous-Tertiary)

C) The Late Pleistocene die-off

D) The P-Tr (Permian-Triassic)

Answer · why

B) The K-T (Cretaceous-Tertiary)

'Tertiary' was dropped as a formal period name in favour of Paleogene.

Q 04/05

Which metal, more common in asteroids than in Earth's crust, is unusually abundant in the K-Pg clay?

A) Nickel

B) Iridium

C) Uranium

D) Platinum

Answer · why

B) Iridium

The Alvarez team found it at 20 to 160 times normal levels in the sections they first studied.

Q 05/05

Which father-and-son team proposed in 1980 that an asteroid impact killed the dinosaurs?

A) Luis and Walter Alvarez

B) William and Lawrence Bragg

C) Charles and Francis Darwin

D) Louis and Richard Leakey

Answer · why

A) Luis and Walter Alvarez

Luis was a Nobel-winning physicist and Walter a geologist; chemists Frank Asaro and Helen Michel co-authored the study.