The Devonian Mass Extinction (359 MYA)

The Late Devonian Mass Extinction wiped out as much as 45% of all life. Corals were almost wiped out completely.Giant armored fish vanished forever, but sharks living today have hardly changed from this time. The cause of the extinction is believed to be changing sea levels or salinity in the oceans changed. During the this period fish had crawled on land to become amphibians and the first trees appeared.

Dinichthys, an armored, shark-like fish that died out in the mass extinction of the Devonian

The Ordovician Mass Extinction (450-435 MYA)

The Ordovician Mass Extinction occurred long before any animals had appeared on land.  It was the second most devastating mass extinction to ever affect the planet. As much as 50% of all species disappeared forever. The trilobites, many legged shelled creatures, were most affected. The cause of this extinction was due to a long ice age. The water began to freeze into great ice sheets at the South Pole, and the sea levels dropped dramatically. Another possibility is that a giant star, thousands of times bigger than our own sun, far out in space, started to collapse in on itself. Then it exploded, sending highly harmful gamma rays toward the Earth, poisoning the seas and atmosphere with high radioactivity.

The Ordovician sea before the mass extincion

Mass Extinction Week!

Hi! Starting tomorrow is mass extinction week. Will cover different mass extinctions through until Saturday. A mass extinction is when an enormous amount species go extinct at one time. There have been five major mass extinctions in the Earths history. They all have been very devastating. Please check each day for a new post.

Cool Picture of the Late Cretaceous Period

The Late Cretaceous period, 67 million years ago. The Dinosaurs in this picture are (left to right) Triceratops, Tyrannosaurus Rex, Ankylosaurus, and a Trachodon or Edmontosaurus