circa 530,000,000 BCE — The first animals leave the ocean

The earliest known fossil footprints on land actually predate the earliest definitively land-based animals fossils by a considerable margin: 170 million years. It appears that our early ancestors may have explored the land before they moved there permanently. In fact, fossil records suggest that this exploration began before there were even terrestrial (as opposed to aquatic) plants – which may account for this peculiarity: no plants would have meant no food.

The first known animals to leave the ocean for good were members of the superclass Tetrapoda, a large group that includes all amphibians, reptiles, birds, and mammals, living and extinct. Including us.

circa 580,000,000 years ago — The first animals evolve

The Proterozoic Eon, which began some 2.5 billion years ago and ended about 542 million years ago, was traditionally regarded as the last era before the evolution of what we would recognise as animals. But more recent fossil discoveries have repainted this picture, and it now appears that animals roughly midway through the Ediacaran Period.

The earliest animals were very simple creatures- small invertebrate multi-cellular forms like the earliest worms and such. Arthropods evolved shortly thereafter, and would go on to become the most dominant type of animal on the planet – just think how many insects and spiders and such you see each day if you don’t believe that.