During the Devonian period (417 ~ 360 mya) one of the most important changes in the history of life on earth took place. It was during this time that backboned animals began to venture out of primordial bodies of water and onto terra firma, begetting a line of vertebrate land dwellers that eventually led to amphibians, reptiles, and mammals such as ourselves.
While we are descendants of the first backboned creatures to venture onto dry land, the first land vertebrates looked nothing like us. Indeed, they had a bizarre, otherworldly appearance, and resembled something of a cross between a fish and a salamander. Their fossil remains have been discovered in Devonian period rocks, many of which are located in northern Canada.
For those of you who are interested, here is a link to the Wikipedia page for the Devonian period: