Mass Extinctions

Question 1

2nd largest mass extinctions, (Hirthanian - Rhuddanian Mass Extinction), 85% casualties both on marine and land species, 60% of marine invertebrates died

Answer 1

Ordovician - Silurian ( mass extinctions ) - 450 - 440 ma

Question 2

Causes of Ordovician - Silurian mass extinctions.

Answer 2

Gondwana moved southwards resulting to extensive glaciation and sea level fall.

Question 3

5th largest mass extinctions, ( Frasnian - Famennian) Mass extinction, 80% of all living species, primarily the marine community have been wiped out. extinction of cooksania, tribulate corals, stromatoporoids, ostracoderms, and placoderms.

Answer 3

Late devonian mass extinctions

Question 4

also known as the “great dying”; largest mass extinctions, eliminations of over 95% of marine and 70% of terrestrial species, extinctions of trilobites, eurypterids, acanthodians, blastoids.

Answer 4

Permian - Triassic mass extinctions

Question 5

Causes of Permian - Triassic Mass extinctions

Answer 5

Bolide Impacts, Increased Volcanism, Suddn release of methane from sea floor, Sea level change, anoxia, aridity

Question 6

Marine genera observed extinction: 53%
Calculated Marine Species extinct: 80%
extinction of conodonts

Answer 6

Triassic - Jurassic mass extinctions

Question 7

75% of all species lost

Extinction of Dinosaurs and ammonites

Answer 7

Cretaceous - Tertiary (K-t/K-pg) Mass Extinction

Question 8

Possible causes of Cretaceous - Tertiary Mass extinctions

Answer 8

Meteorite Impact

Question 9

Evidence for Cretaceous - Tertiary mass extinctions

Answer 9

Iridium layer (k-pg)
Chixulub Crater ( 150 km) Yucatan Peninsula in Mexico.