According to Earth System Science Education, the first land animals appeared toward the middle of the Paleozoic Era, in the late Silurian period. The earliest animals to adapt to the land were small arthropods similar to... More »

The first occurrence of simple animals was approximately 600 million years ago. These were characterized as multi-cellular organisms with basic structures, but no true tissues. An example would be a jellyfish or marine s... More »

As of April 2014, no animals other than human beings have landed on the moon. The first humans to land on the moon were Neil Armstrong and Edwin Aldrin. Armstrong was the first human to step on the moon. More »

The first occurrence of simple animals was approximately 600 million years ago. These were characterized as multi-cellular organisms with basic structures, but no true tissues. An example would be a jellyfish or marine s... More »

The climate of the Paleozoic Era varied as the period began with large glaciers covering the surface of the Earth, which gave way to warmer temperatures, glacial melt and volcanic activity. The Paleozoic Era existed 545 ... More »

Dinosaurs first walked the earth 230 million years ago and dominated the land for 160 million years. They became extinct 65 million years ago during the Cretaceous period. More »

As of 2015, scientists believe the first animal on Earth was the comb jelly of the phylum Ctenophora. It is an ocean-dwelling, gelatinous organism whose length varies from less than half an inch to 16 inches. Until 2008,... More »