Our Human Ancestors Had Tentacles
Wednesday, April 22, 2015 - 16:20
in Paleontology & Archaeology
The famous Vitruvian Man, drawn by Leonardo da Vinci, pictures the canon of human's proportions - though we did not become bilaterally symmetric all at once. There are two main points of view on the last common bilaterian ancestor, its appearance and the course of evolution. It is likely that the ancestor of Bilateria appeared at the end of the Vendian period which is the last geological period of the Neoproterozoic Era preceding the Cambrian Period. It lasted from approximately 635 to 541±1 million years ago. The organisms, which lived in the Vendian sea, were mostly radially symmetrical creatures. Some of them were floating in the water, while others were crawling along the bottom or leading sessile benthic life. read more