Late Paleozoic part 2

By the Carboniferous, freshwater lakes and streams were inhabited by numerous species of fishes, especially ___-______ fishes and sharks.

Until the Permian Period, __________ were the dominant terrestrial vertebrates.

Reptiles appeared in the late Carboniferous, and in the Permian they began diversifying into the groups we know as _________ (lizards and snakes), __________ (crocodiles, dinosaurs, and flying reptiles), and others.

More than 90% of all marine species are estimated to have become extinct in the waning stages of the Permian Period.

• True

• False

Answer explanation

Over 80% of marine species are believed to have become extinct in the later Permian period.

Which marine species was among the few to survive the late Permian extinction event and survive into the triassic period?

• Trilobites

• Brachiopods

• Placoderms

• Ammonoids

Extinction was so severe among terrestrial vegetation that ____ _____, which result from the accumulation of peat, are absent from strata of the Early ________.

Aridification of vast areas led to widespread _________ deposition.

Carbon isotopes in sediments became enriched in ______-__ close to the end of the Permian Period, and organic-rich sediments attest to ______ conditions in the deep sea.

Finally, the rate of extinction at the end of the Permian Period may have been accelerated by the impact of a meteorite or comet.

• True

• False

Upper Permian strata are unusually enriched in soccer- ball shaped carbon molecules, called __________, that contain argon and helium-3 atoms.