Biogeographical Evidence: The following website introduces the

biogeographical evidence and shows the movement of the continents from Pangaea (the earliest supercontinent from which all continents arose) to present dayPangaea - ZoomSchool.com

Pangaea broke into 2 smaller supercontinents during late Triassic.

Evidence of common Plant life and animal life can be found on all continents, giving support to this theory – eg. Glossopteris (fossil fern) found on every southern continent – India, South America, Australia, Antarctica, and Southern Africa

First aquatic reptile, Mesosarus, (lived before the dinosaurs) fossils were found in both South Africa and South America, supporting the theory

Seven “missing link” fossils

There was a mass extinction at end of Permian Period (last period of Paleozoic, right before Jurassic Period)

During the Triassic, Jurassic and Cretaceous (periods of the Mesozoic Era) many new species were formedTriassic: Dinosaurs, Mammals, flying reptiles,

amphibians Jurassic: birds

at the end of the Cretaceous period (called the K – T extinction), which wiped out 85% of all species including the dinosaurs

65 mya The K-T Extinction was the second largest Called K – T because it occurred at the

boundary of the Cretaceous and Tertiary periods, K is used for

Cretaceous

The cause of the mass extinction is generally believed to be a meteorite colliding with earth.

Evidence supporting the meteor or comet showers theoryA layer of sediment deposited at that time

in Earth’s history contains incredibly high amounts of Iridium

Iridium is found only in Earth’s mantle and in outer space

Volcanic eruptions are another viable theory due to Iridium in Earth’s mantle