Amphioxus

This small organism known as Amphioxus, or as Lancelet is believed to be the precursor to modern vertebrates. This is believed because this organism has been around for millions of years. It has a basic structure but it has many of the basic parts that set apart vertebrates from other organisms. Its basic structure and its old origins have led to the belief that it is an early basis for what evolved into modern vertebrates. Another characteristic that supports this theory is the study of the Lanelet genome. When studying the genome scientist find that it is by far the most basic chordate identified. This means that it was the first to split from the common ancestor from all chordates that predates the Cambrian Era. It being the first split shows that it is the origin of today's vertebrates.